Artificial hair fibers and hair ornaments

Abstract

The present invention provides artificial hair fibers capable of adequately maintaining the appearance of a braided structure when the braided structure is brought into contact with 75°C hot water, and hair ornaments equipped with such artificial hair fibers. [Solution] A fiber for artificial hair that has a tanδ peak of 88°C or less in dynamic viscoelasticity measurement at a frequency of 1 Hz in water. A hair accessory comprising the artificial hair fiber.

Description

Technical Field

[0001] The present invention relates to fibers for artificial hair, hair ornaments, and the like.

Background Art

[0002] Fibers for artificial hair (fibers used for artificial hair) can be used in hair ornaments. As fibers for artificial hair, studies have been made to obtain an appearance equivalent to that of human hair (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] After incorporating fibers for artificial hair to obtain a knitted structure, the appearance of the knitted structure can be adjusted by bringing the knitted structure into contact with warm water. In this case, although warm water at a high temperature such as 95°C can be used, when the temperature of the warm water decreases over time, it may be difficult to continue to adjust the appearance of the knitted structure using this warm water. Therefore, it is desirable that the appearance of the knitted structure can be sufficiently adjusted even when the temperature of the warm water decreases over time and, for example, warm water at 75°C is used.

[0005] One aspect of the present invention is to provide fibers for artificial hair that can sufficiently adjust the appearance of a knitted structure when the knitted structure of the fibers for artificial hair is brought into contact with warm water at 75°C. Another aspect of the present invention is to provide a hair ornament provided with such fibers for artificial hair.

Means for Solving the Problems

[0006] In some respects, the present invention relates to the following [1] to [4], etc. [1] A fiber for artificial hair that has a tanδ peak of 88°C or less in dynamic viscoelasticity measurements at a frequency of 1 Hz in water. [2] The artificial hair fiber according to [1], wherein the temperature of the tanδ peak is 50 to 88°C. [3] A fiber for artificial hair according to [1] or [2], containing a vinyl chloride polymer. A hair ornament comprising artificial hair fibers as described in any one of [4][1] to [3]. [Effects of the Invention]

[0007] According to one aspect of the present invention, it is possible to provide artificial hair fibers that can sufficiently improve the appearance of the braided structure when the braided structure of the artificial hair fibers is brought into contact with hot water at 75°C. According to another aspect of the present invention, it is possible to provide a hair ornament comprising such artificial hair fibers. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described in detail below.

[0009] In numerical ranges, "greater than or equal to A" means A and the range greater than A. In numerical ranges, "less than or equal to A" means A and the range less than A. In numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. In numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. "A or B" means that either A or B is included, or both are included. Unless otherwise specified, the materials exemplified in this specification can be used individually or in combination of two or more. The content of each component in a composition means the total amount of multiple substances present in the composition if there are multiple substances corresponding to each component in the composition, unless otherwise specified. The term "process" is included not only in the sense of an independent process, but also in the sense that the intended function of the process is achieved even if it cannot be clearly distinguished from other processes. "(meth)acrylic acid" means at least one of acrylic acid and the corresponding methacrylic acid. The same applies to other similar expressions such as "(meth)acrylate".

[0010] The artificial hair fibers according to this embodiment have a tanδ peak (loss tangent peak) of 88°C or less in dynamic viscoelasticity measurements at a frequency of 1 Hz in water. The artificial hair fibers according to this embodiment can be used as artificial hair (for example, as a base fiber for artificial hair), and can also be used to obtain artificial hair. The artificial hair fibers according to this embodiment may be fibers after stretching treatment, or they may be unstretched fibers.

[0011] The braided structure (braided body; braided structure) according to this embodiment is a braided structure of artificial hair fibers according to this embodiment, and can be obtained by braiding the artificial hair fibers according to this embodiment. The braided structure according to this embodiment is not particularly limited and includes two-strand braids, three-strand braids, four-strand braids, five-strand braids, six-strand braids, eight-strand braids, etc.

[0012] The inventors have discovered that the appearance of the braided structure of artificial hair fibers can be adjusted when the braided structure of the artificial hair fibers is brought into contact with warm water, by using the temperature of the tanδ peak of the artificial hair fibers obtained by dynamic viscoelasticity measurement in water as an indicator. According to the artificial hair fibers of this embodiment, it is possible to sufficiently adjust the appearance of the braided structure when the braided structure of the artificial hair fibers (e.g., fiber bundles of artificial hair fibers) is brought into contact with warm water at 75°C. For example, by bringing protruding fibers into contact with warm water to adjust the orientation of the fibers, the appearance of the braided structure can be sufficiently adjusted (excellent shape cohesion can be obtained). For example, according to the artificial hair fibers of this embodiment, in the evaluation method described in the examples below, by using warm water at 75°C, it is possible to obtain a state in which fibers that protrude from the braid before treatment are aligned with the braiding direction after treatment (a state in which the orientation of the fibers is adjusted by treatment).

[0013] The inventors speculate that the reason why the appearance of the braided structure can be sufficiently refined when exposed to 75°C hot water is as follows: The temperature of the tanδ peak of the artificial hair fibers obtained by dynamic viscoelasticity measurement in water correlates with how easily the artificial hair fibers soften when exposed to hot water. When the temperature of such a tanδ peak is low, the fibers soften easily in hot water, and the orientation of the fibers is easily adjusted. Therefore, the appearance of the braided structure can be sufficiently refined when exposed to 75°C hot water. However, the reason why the appearance of the braided structure can be sufficiently refined is not limited to the above.

[0014] In the artificial hair fibers according to this embodiment, it is sufficient that the appearance of the braided structure is sufficiently smoothed when using 75°C hot water, and the appearance of the braided structure may be smoothed using hot water at other temperatures depending on the application. According to one embodiment of the artificial hair fibers according to this embodiment, the appearance of the braided structure can be sufficiently smoothed when the braided structure of the artificial hair fibers is brought into contact with 95°C hot water.

[0015] The artificial hair fibers according to this embodiment have a tanδ peak (hereinafter sometimes referred to as "peak P") below 88°C in dynamic viscoelasticity measurements at a frequency of 1 Hz in water, from the viewpoint of ensuring a good appearance of the braided structure when exposed to 75°C hot water. If multiple tanδ peaks are observed in the temperature range of 88°C or below, the temperature of the peak with the largest tanδ can be used as the temperature of peak P. Peak P may be a peak derived from the monomer units of vinyl chloride in the vinyl chloride polymer. The temperature of peak P can be measured under the conditions described in the examples. The temperature of peak P can be adjusted by the type and content of the components contained in the artificial hair fibers, for example, by the type and content of the plasticizer.

[0016] The temperature of peak P (peak temperature) may be 87°C or lower, 86°C or lower, 85°C or lower, 83°C or lower, 80°C or lower, 78°C or lower, 77°C or lower, 75°C or lower, 70°C or lower, 65°C or lower, 60°C or lower, 55°C or lower, or 54°C or lower, from the viewpoint of easily obtaining a good tactile feel for the artificial hair fibers. From these perspectives, the temperature of peak P may be 40-88°C, 40-80°C, 40-70°C, 40-60°C, 50-88°C, 50-80°C, 50-70°C, 50-60°C, 60-88°C, 60-80°C, 70-88°C, or 70-80°C.

[0017] The artificial hair fibers according to this embodiment may contain polymers. The polymer may be a resin material. Examples of polymers include vinyl chloride polymers, polyester polymers, polyamide polymers, polyolefin polymers, vinyl acetate polymers (ethylene-vinyl acetate copolymer (EVA), etc.), acrylonitrile polymers (acrylonitrile-butadiene rubber (NBR), acrylonitrile-butadiene-styrene polymer (ABS), acrylonitrile-styrene copolymer (AS), etc.), thermoplastic polyurethane (TPU), polyester thermoplastic elastomer (TPEE), methyl methacrylate-butadiene-styrene polymer (MBS), and polymethyl methacrylate (PMMA). If a polymer that could be classified as a polymer other than a vinyl chloride polymer has a monomer unit of vinyl chloride, that polymer is defined as a vinyl chloride polymer. As polymers, one type can be used alone or two or more types can be used in combination. For example, a vinyl chloride polymer and acrylonitrile-styrene copolymer (AS) can be used in combination.

[0018] The artificial hair fibers according to this embodiment may contain a vinyl chloride polymer, from the viewpoint of easily shaping the appearance of the braided structure when brought into contact with warm water (for example, warm water at 75°C). The vinyl chloride polymer is a polymer having vinyl chloride as a monomer unit (a polymer having vinyl chloride monomer units). The vinyl chloride polymer can be obtained by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc.

[0019] Examples of vinyl chloride polymers include homopolymers (homopolymers, polyvinyl chloride) of vinyl chloride, copolymers of vinyl chloride with other monomers, and mixtures thereof may be used. Examples of copolymers of vinyl chloride with other monomers include copolymers of vinyl chloride with vinyl esters (vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl propionate copolymer, etc.); copolymers of vinyl chloride with (meth)acrylic acid compounds ((meth)acrylic acid, (meth)acrylic acid ester, etc.) (vinyl chloride-butyl acrylate copolymer, vinyl chloride-2-ethylhexyl acrylate copolymer, etc.); copolymers of vinyl chloride with the polyfunctional monomers described later; copolymers of vinyl chloride with olefins (vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, etc.); and vinyl chloride-acrylonitrile copolymer. Vinyl chloride polymers do not necessarily have monomer units of (meth)acrylic acid compounds.

[0020] The vinyl chloride polymer may contain a crosslinked vinyl chloride resin, and may also contain a non-crosslinked vinyl chloride resin, from the viewpoint of easily shaping the appearance of the braided structure when brought into contact with hot water (for example, hot water at 75°C). "Crosslinking" in the crosslinked vinyl chloride resin means that it has branching points in the polymerization chain (for example, branching points where the carbon chains of the side chains branch off from the carbon chains of the main chain) and is not linear. "Non-crosslinking" in the non-crosslinked vinyl chloride resin means that it does not have branching points in the polymerization chain (for example, branching points where the carbon chains of the side chains branch off from the carbon chains of the main chain) and is linear.

[0021] Crosslinked vinyl chloride resins can be obtained by adding polyfunctional monomers during the polymerization of vinyl chloride. Examples of polyfunctional monomers include di(meth)acrylate compounds such as polyethylene glycol di(meth)acrylate and bisphenol A-modified di(meth)acrylate. Crosslinked vinyl chloride resins may be a mixture of a gel component having a crosslinked structure and mainly composed of vinyl chloride monomer units, and a polyvinyl chloride component (a component consisting of vinyl chloride monomer units). The gel component tends to be insoluble in tetrahydrofuran, while the polyvinyl chloride component tends to be soluble in tetrahydrofuran.

[0022] When the content of the non-crosslinked vinyl chloride resin in the vinyl chloride polymer is brought into contact with warm water (for example, warm water at 75°C), from the viewpoint of facilitating the appearance of the knitted structure, based on the total mass of the vinyl chloride polymer, it may be 50% by mass or more, more than 50% by mass, 70% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more. The vinyl chloride polymer may be in a form consisting essentially of only the non-crosslinked vinyl chloride resin (substantially 100% by mass of the vinyl chloride polymer is the non-crosslinked vinyl chloride resin).

[0023] From the viewpoint of facilitating the appearance of the knitted structure when the polymer is brought into contact with warm water (for example, warm water at 75°C), the polymer may contain a non-crosslinked vinyl chloride resin having the following viscosity average degree of polymerization. The viscosity average degree of polymerization may be 100 or more, 300 or more, 400 or more, 500 or more, 600 or more, 700 or more, 800 or more, 900 or more, or 1000 or more. The viscosity average degree of polymerization may be 3000 or less, 2500 or less, 2000 or less, 1500 or less, 1200 or less, or 1000 or less. From these viewpoints, the viscosity average degree of polymerization may be 100 - 3000, 100 - 2000, 100 - 1500, 500 - 3000, 500 - 2000, 500 - 1500, 800 - 3000, 800 - 2000, or 800 - 1500. The viscosity average degree of polymerization can be measured with an Ubbelohde viscometer in a constant temperature bath at 30°C for the specific viscosity of the solution obtained by dissolving 200 mg of the non-crosslinked vinyl chloride resin in 50 mL of nitrobenzene and calculated according to JIS K 6721.

[0024] When the polymer is brought into contact with warm water (for example, warm water at 75°C), from the viewpoint of facilitating the appearance of the knitted structure, based on the total mass of the polymer, the content of the vinyl chloride polymer in the polymer may be 50% by mass or more, more than 50% by mass, 70% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more. The polymer may be in a form consisting essentially of only the vinyl chloride polymer (substantially 100% by mass of the polymer is the vinyl chloride polymer).

[0025] The polymer may include a vinyl chloride-based polymer and a mixture of components capable of forming a polymer alloy with the vinyl chloride-based polymer. Examples of components capable of forming a polymer alloy with the vinyl chloride-based polymer include ethylene vinyl acetate copolymer (EVA), acrylonitrile butadiene rubber (NBR), thermoplastic polyurethane (TPU), polyester-based thermoplastic elastomer (TPEE), methyl methacrylate butadiene styrene polymer (MBS), acrylonitrile butadiene styrene polymer (ABS), acrylonitrile-styrene copolymer (AS), polymethyl methacrylate (PMMA), and the like.

[0026] Examples of polyester-based polymers include polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polymethylene terephthalate, glycol-modified polyethylene terephthalate, and the like.

[0027] Examples of polyamide-based polymers include nylon 6, nylon 66, nylon 11, nylon 12, nylon 6 / 10, nylon 6 / 12, and the like.

[0028] Examples of polyolefin-based polymers include polyethylene, polypropylene, and the like.

[0029] The polymer content, or vinyl chloride polymer content, may be within the following ranges based on the total mass of the artificial hair fibers. From the viewpoint of easily obtaining an excellent tactile feel for the artificial hair fibers, Content A may be 50% by mass or more, more than 50% by mass, 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 72% by mass or more, 75% by mass or more, 78% by mass or more, 80% by mass or more, 82% by mass or more, 85% by mass or more, or 88% by mass or more. From the viewpoint of easily shaping the appearance of the braided structure when in contact with hot water (for example, hot water at 75°C), Content A may be 90% by mass or less, 89% by mass or less, 88% by mass or less, 85% by mass or less, 82% by mass or less, 80% by mass or less, 78% by mass or less, or 75% by mass or less. From these perspectives, content A may be 50-90% by mass, 50-85% by mass, 50-80% by mass, 50-75% by mass, 70-90% by mass, 70-85% by mass, 70-80% by mass, 70-75% by mass, 80-90% by mass, 80-85% by mass, or 85-90% by mass.

[0030] The artificial hair fibers according to this embodiment may contain plasticizers. Examples of plasticizers include epoxy plasticizers, phthalate plasticizers, isophthalate plasticizers, terephthalate plasticizers, adipic acid plasticizers (excluding plasticizers that fall under the category of polyester plasticizers), polyester plasticizers, phosphate plasticizers, trimellitic acid plasticizers, benzoic acid plasticizers, and the like. Specific examples of plasticizers include epoxidized soybean oil, epoxidized linseed oil, diisonyl phthalate (DINP), diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate (n-DOP), diisodecyl phthalate (DIDP), propylene glycol phthalate-based polyesters, benzyl butyl phthalate (BBP), di-2-ethylhexyl isophthalate (DOIP), and di-2-ethylhexyl terephthalate (DOTP). Examples include diisononyl adipate (DINA), di-2-ethylhexyl adipate (DOA), diisodecyl adipate, benzyloctyl adipate (BOA), adipate-propylene glycol polyester, adipate-butylene glycol polyester, tricresyl phosphate (TCP), diphenylcresyl phosphate (DPCP), tri-2-ethylhexyl trimellitate (TOTM), and oxydiethylene dibenzoate. Plasticizers can be used individually or in combination of two or more; for example, epoxidized soybean oil may be used in combination with other plasticizers.

[0031] The plasticizer may include at least one selected from the group consisting of epoxy plasticizers, phthalate plasticizers, terephthalate plasticizers, adipic acid plasticizers, and polyester plasticizers, from the viewpoint of easily shaping the appearance of the braided structure when it is brought into contact with hot water (for example, hot water at 75°C), and may also include at least one selected from the group consisting of epoxidized soybean oil, disonyl phthalate, di-2-ethylhexyl terephthalate, and diisononyl adipate.

[0032] The plasticizer content may be within the following ranges based on the total mass of the artificial hair fibers. The plasticizer content may be 2.0% by mass or more, 3.0% by mass or more, 4.0% by mass or more, 5.0% by mass or more, 6.0% by mass or more, 7.0% by mass or more, 8.0% by mass or more, 9.0% by mass or more, 10.0% by mass or more, 12.0% by mass or more, 15.0% by mass or more, 18.0% by mass or more, or 20.0% by mass or more, from the viewpoint of making it easier to maintain the appearance of the braided structure when exposed to hot water (for example, hot water at 75°C). The plasticizer content may be 30.0% by mass or less, 25.0% by mass or less, 20.0% by mass or less, 18.0% by mass or less, 15.0% by mass or less, 12.0% by mass or less, 10.0% by mass or less, 9.0% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, or 5.0% by mass or less, from the viewpoint of easily obtaining a good tactile feel for the artificial hair fibers. From these perspectives, the plasticizer content may be 2.0-30.0% by mass, 2.0-20.0% by mass, 2.0-10.0% by mass, 2.0-6.0% by mass, 4.0-30.0% by mass, 4.0-20.0% by mass, 4.0-10.0% by mass, 4.0-6.0% by mass, 5.0-30.0% by mass, 5.0-20.0% by mass, 5.0-10.0% by mass, 10.0-30.0% by mass, or 15.0-30.0% by mass.

[0033] The plasticizer content may be within the following ranges per 100 parts by mass of polymer or 100 parts by mass of vinyl chloride polymer. The plasticizer content may be 2.0 parts by mass or more, 3.0 parts by mass or more, 4.0 parts by mass or more, 5.0 parts by mass or more, 6.0 parts by mass or more, 7.0 parts by mass or more, 8.0 parts by mass or more, 9.0 parts by mass or more, 10.0 parts by mass or more, 12.0 parts by mass or more, 15.0 parts by mass or more, 18.0 parts by mass or more, 20.0 parts by mass or more, 22.0 parts by mass or more, 25.0 parts by mass or more, 28.0 parts by mass or more, or 30.0 parts by mass or more, from the viewpoint of easily shaping the appearance of the braided structure when in contact with hot water (for example, hot water at 75°C). The plasticizer content may be 50.0 parts by mass or less, 45.0 parts by mass or less, 40.0 parts by mass or less, 35.0 parts by mass or less, 30.0 parts by mass or less, 28.0 parts by mass or less, 25.0 parts by mass or less, 22.0 parts by mass or less, 20.0 parts by mass or less, 18.0 parts by mass or less, 15.0 parts by mass or less, 12.0 parts by mass or less, 10.0 parts by mass or less, 9.0 parts by mass or less, 8.0 parts by mass or less, 7.0 parts by mass or less, 6.0 parts by mass or less, or 5.0 parts by mass or less, from the viewpoint of easily obtaining a good tactile feel for the artificial hair fibers. From these perspectives, the plasticizer content may be 2.0 to 50.0 parts by mass, 2.0 to 30.0 parts by mass, 2.0 to 10.0 parts by mass, 2.0 to 8.0 parts by mass, 4.0 to 50.0 parts by mass, 4.0 to 30.0 parts by mass, 4.0 to 10.0 parts by mass, 4.0 to 8.0 parts by mass, 6.0 to 50.0 parts by mass, 6.0 to 30.0 parts by mass, 6.0 to 10.0 parts by mass, 10.0 to 50.0 parts by mass, or 20.0 to 50.0 parts by mass.

[0034] The artificial hair fibers according to this embodiment may contain components other than those described above (polymers, plasticizers, etc.). Examples of such components include heat stabilizers, lubricants, antistatic agents, flame retardants, flame retardant additives, ultraviolet absorbers, light stabilizers, fluorescent agents, antioxidants, and the like.

[0035] Examples of heat stabilizers include Ca-Zn-based heat stabilizers, hydrotalcite-based heat stabilizers, tin-based heat stabilizers, and β-diketone-based heat stabilizers.

[0036] Examples of Ca-Zn-based heat stabilizers include zinc stearate, calcium stearate, zinc 12-hydroxystearate, and calcium 12-hydroxystearate.

[0037] Examples of hydrotalcite-based heat stabilizers include complex salt compounds consisting of magnesium and / or alkali metals and aluminum or zinc, complex salt compounds consisting of magnesium and aluminum, and compounds obtained by dehydrating the crystal water of these complex salt compounds.

[0038] Examples of tin-based heat stabilizers include mercapto-tin heat stabilizers such as dimethyl tin mercapto, dimethyl tin mercaptide, dibutyl tin mercapto, dioctyl tin mercapto, dioctyl tin mercapto polymer, and dioctyl tin mercapto acetate; maleate-tin heat stabilizers such as dimethyl tin maleate, dibutyl tin maleate, dioctyl tin maleate, and dioctyl tin maleate polymer; and laurate-tin heat stabilizers such as dimethyl tin laurate, dibutyl tin laurate, and dioctyl tin laurate.

[0039] Examples of β-diketone-based heat stabilizers include stearoylbenzoylmethane and dibenzoylmethane.

[0040] Examples of lubricants include metal soap-based lubricants, higher fatty acid-based lubricants, ester-based lubricants, and higher alcohol-based lubricants.

[0041] Examples of metal soap-based lubricants include metal soaps such as stearates, laurates, palmitates, and oleates of Na, Mg, Al, Ca, and Ba.

[0042] Examples of higher fatty acid-based lubricants include saturated fatty acids such as stearic acid, palmitic acid, myristic acid, lauric acid, and capric acid; unsaturated fatty acids such as oleic acid; and mixtures thereof.

[0043] Examples of ester-based lubricants include ester-based lubricants consisting of an alcohol and a fatty acid; pentaerythritol-based lubricants such as monoesters, diesters, triesters, tetraesters, or mixtures thereof of pentaerythritol or dipentaerythritol and a higher fatty acid; and montanic acid wax-based lubricants such as esters of montanic acid and a higher alcohol (stearyl alcohol, palmityl alcohol, myristyl alcohol, lauryl alcohol, oleyl alcohol, etc.).

[0044] Examples of higher alcohol-based lubricants include stearyl alcohol, palmityl alcohol, myristyl alcohol, lauryl alcohol, and oleyl alcohol.

[0045] The single fineness of the artificial hair fibers according to this embodiment may be within the following ranges after the stretching treatment. The single fineness may be 20 decitex or more, 30 decitex or more, 40 decitex or more, or 50 decitex or more. The single fineness may be 100 decitex or less, 90 decitex or less, 80 decitex or less, or 70 decitex or less. From these viewpoints, the single fineness may be between 20 and 100 decitex.

[0046] The method for producing artificial hair fibers according to this embodiment may include a spinning step in which a composition containing the components of the artificial hair fibers (polymer, plasticizer, etc.) is spun. In the spinning step, the composition containing the components of the artificial hair fibers (polymer, plasticizer, etc.) can be melt-spun (melt-deformed).

[0047] The method for producing artificial hair fibers according to this embodiment may include a kneading step before the spinning step in which a composition containing the components of the artificial hair fibers (polymer, plasticizer, etc.) is melt-kneaded. Various general kneaders can be used as the apparatus for melt-kneading. Examples of kneaders include single-screw extruders, twin-screw extruders, rolls, Banbury mixers, kneaders, etc.

[0048] The method for manufacturing fibers for artificial hair according to this embodiment may include a stretching step after the spinning step, in which the yarn (unstretched yarn) obtained in the spinning step is stretched.

[0049] The stretch ratio in the stretching process may be 1.5 times or more, or 2.0 times or more, from the viewpoint of easily developing fiber strength. The stretch ratio may be 5.0 times or less, or 4.0 times or less, from the viewpoint of minimizing yarn breakage during the stretching process. From these viewpoints, the stretch ratio may be between 1.5 and 5.0 times.

[0050] The drawing process may be carried out in a two-step method in which the undrawn yarn is first wound onto a bobbin and then drawn in a step that is not continuous with the spinning process, or it may be carried out in a direct spinning and drawing method in which the undrawn yarn is drawn in a step that is continuous with the spinning process without first winding it onto a bobbin. The drawing process may be carried out in a single-step drawing method in which the yarn is drawn to the desired drawing ratio in one step, or it may be carried out in a multi-step drawing method in which the yarn is drawn to the desired drawing ratio by drawing it two or more times.

[0051] The temperature for the stretching process may be between 80 and 120°C. A temperature of 80°C or higher makes it easier to ensure sufficient fiber strength and reduces the likelihood of yarn breakage. A temperature of 120°C or lower makes it easier to obtain a desirable texture for the fiber.

[0052] The method for manufacturing fibers for artificial hair according to this embodiment may include a heat treatment step after the stretching step, in which the yarn obtained in the stretching step (stretched yarn) is heat-treated (annealed). By performing the heat treatment step, the thermal shrinkage rate of the stretched yarn can be reduced.

[0053] The heat treatment temperature may be 100°C or higher, or 120°C or higher. The heat treatment temperature may be 200°C or lower, or 150°C or lower. From these viewpoints, the heat treatment temperature may be between 100°C and 200°C. The heat treatment may be performed immediately after the stretching treatment, or it may be performed after a period of time has passed since the material was wound up.

[0054] The method for manufacturing artificial hair fibers according to this embodiment may include a gear processing step in which the artificial hair fibers are subjected to a gear processing treatment (shaping treatment). The gear processing treatment is a process in which the fibers are crimped by passing them between two meshing, high-temperature gears. The gear processing step can be performed after the spinning step, and may be performed after the heat treatment step described above. In the gear processing treatment, the material of the gears, the gear waveform, the number of gears, etc., are not particularly limited.

[0055] The method for manufacturing artificial hair fibers according to this embodiment may include a hot water treatment step in which the artificial hair fibers are brought into contact with (e.g., immersed in) hot water. The hot water treatment step can be performed after the spinning step, after the heat treatment step described above, or after the gear processing step described above. The temperature of the hot water may be 70-100°C, 75-100°C, or 75-95°C.

[0056] The hair ornament according to this embodiment comprises artificial hair fibers according to this embodiment. The hair ornament according to this embodiment is an article that can be attached to and detached from the head, and may be an embodiment consisting of artificial hair fibers according to this embodiment (for example, a fiber bundle of artificial hair fibers). Examples of hair ornaments include wigs, hairpieces, braids, hair extensions, and hairpieces. [Examples]

[0057] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0058] <Production of fibers for artificial hair> A polymer (manufactured by OCEAN PVC CO., LTD., trade name: TH1000, uncrosslinked vinyl chloride resin, homopolymer of vinyl chloride, viscosity average degree of polymerization: 1000), a plasticizer (manufactured by Chang Chun Petrochemical Co., Ltd., trade name: Epoxidized Soybean Oil / ESBO / ESBOD, epoxidized soybean oil), and an additive (such as a heat stabilizer) were mixed with a blender to obtain a vinyl chloride resin composition. At a cylinder temperature of 130 to 170 °C, pellets were produced by compounding this vinyl chloride resin composition using an extruder with a diameter of 65 mm. Fiber A was obtained by melt spinning these pellets using an extruder with a diameter of 40 mm. The cylinder temperature in the melt spinning was 150 to 190 °C. Fiber B with an average fineness of 140 decitex was obtained by heat-treating Fiber A for about 0.5 to 1.5 seconds with a heating cylinder provided immediately below the nozzle. After stretching Fiber B by 300% in an air atmosphere at 100 °C, heat shrinkage was performed in an air atmosphere at 120 °C until the total fiber length shrank to 80% of the length before treatment, thereby obtaining a fiber for artificial hair with 56 decitex. Table 1 shows the contents of the polymer and the plasticizer based on the total mass of the fiber for artificial hair. The content of the additive is the remainder obtained by subtracting the contents of the polymer and the plasticizer from the total mass of the fiber for artificial hair.

[0059] <Production of fiber bundle> Using a gear machine (NEW YAKI BRAID CRIMPING M / C - 2.5mm / SUNG JIN INDUSTRIAL CO., LTD.), the above-mentioned fiber for artificial hair was shaped under the conditions of a gear pitch of 2.5 mm, preheating at 80 °C, a gear roll temperature of 80 °C, and a gear roll rotation speed of 1 m / min. Then, the fibers were bundled to obtain a fiber bundle with a length of 400 mm and a mass of 5.1 g.

[0060] <Measurement of temperature of tanδ peak> Four artificial hair fibers were extracted from the aforementioned fiber bundle. Next, the four fibers were arranged in a line with adjacent fibers in contact with each other, fixed with a jig, and then immersed in a container of water. The dynamic viscoelasticity of the fibers in water was then measured using a measuring device (TA instruments, product name: RSA-G2), and the peak temperature of the tanδ peak was obtained. The underwater measurement unit of this device was used, with measurement conditions of a heating rate of 1°C / min, a chuck distance of 10 mm, a frequency of 1 Hz, a strain of 0.1%, tensile mode, and a measurement temperature range of 25-96°C. The water temperature in the container was increased at a heating rate of 1°C / min within the measurement temperature range of 25-96°C. The peak temperature measurement results are shown in Table 1. In Examples 1-3 and Comparative Examples 1-2, only one peak was observed in the temperature range of 25-96°C.

[0061] <Exterior Evaluation> A braided structure was created using the aforementioned fiber bundle, which was 400 mm long and weighed 5.1 g. This braided structure was then immersed in water at 95°C or 75°C for 15 seconds. Next, after removing the braided structure from the water, the water was wiped off by lightly rubbing the surface of the braided structure three times. After natural drying at room temperature (25°C) for more than 24 hours, the appearance of the braided structure was visually observed. A good braid was judged as "A," and a poor braid was judged as "B." A good condition was defined as when fibers that were protruding from the braid before treatment were aligned with the braiding direction after treatment (a state in which the direction of the fibers was aligned by the treatment). The results are shown in Table 1.

[0062] [Table 1]

Claims

1. A fiber for artificial hair that exhibits a tanδ peak below 88°C in dynamic viscoelasticity measurements at a frequency of 1 Hz in water.

2. The artificial hair fiber according to claim 1, wherein the temperature of the tanδ peak is 50 to 88°C.

3. The artificial hair fiber according to claim 1, comprising a vinyl chloride polymer.

4. A hair ornament comprising the artificial hair fiber described in any one of claims 1 to 3.

Images