Fiber for artificial hair, hair ornament, and method for producing fiber for artificial hair

Abstract

Provided is a fiber for artificial hair having an appropriate heat shrinkage rate. The present invention provides a fiber for artificial hair comprising a polyvinyl chloride-based resin and a chlorinated polyvinyl chloride-based resin having a chlorine content of 64.0-67.0 mass%. The chlorinated polyvinyl chloride-based resin contains a first chlorinated polyvinyl chloride-based resin having a chlorine content of 64.0-68.0 mass%. The fiber for artificial hair contains 5 to 30 parts by mass of the first chlorinated polyvinyl chloride-based resin having a chlorine content of 64.0-67.0 mass% with respect to 100 parts by mass of the polyvinyl chloride-based resin. The fiber for artificial hair has a storage elastic modulus E' at 105 °C of 1.5 × 107 - 4.5 × 107 in a dynamic viscoelasticity measurement at a frequency of 1 Hz.

Description

Artificial hair fiber, hair accessories, and method for manufacturing artificial hair fiber

[0001] The present invention relates to a fiber for artificial hair, a hair accessory, and a method for producing a fiber for artificial hair.

[0002] As materials for artificial hair fibers, fibers made of acrylic resin, vinyl chloride resin, or polyester fiber are commercially available. For example, vinyl chloride resin is used because it is easy to process and low cost. Vinyl chloride resin fibers have excellent strength and elongation, and are used, for example, as artificial hair fibers for hair accessories.

[0003] Patent Document 1 discloses a polyvinyl chloride fiber characterized by comprising a vinyl chloride resin composition obtained by blending, with respect to 100 parts by weight of (a) vinyl chloride resin, (b) 1 to 6 parts by weight of a plasticizer, (c) 0.2 to 5 parts by weight of a heat stabilizer, (d) 0.2 to 5 parts by weight of a lubricant, (e) 0.2 to 5 parts by weight in total of one or more acrylic polymers having a specific viscosity of 0.08 or more and less than 0.5, and (f) 0.2 to 5 parts by weight in total of one or more acrylic polymers having a specific viscosity of 0.5 or more.

[0004] Japanese Patent Application Laid-Open No. 2004-156149

[0005] In recent years, artificial hair fibers have been required to have an appropriate heat shrinkage when exposed to a high-temperature environment. However, conventional artificial hair fibers have either too large or too small heat shrinkage, making it difficult to obtain artificial hair fibers with an appropriate heat shrinkage.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a fiber for artificial hair having an appropriate heat shrinkage rate.

[0007] According to the present invention, there is provided an artificial hair fiber comprising a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, wherein the chlorinated polyvinyl chloride resin comprises a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 68.0% by mass, and the artificial hair fiber comprises 5 to 30 parts by mass of the first chlorinated polyvinyl chloride resin per 100 parts by mass of the polyvinyl chloride resin, and the artificial hair fiber has a storage modulus E' at 105°C of 1.5 x 10 in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ The present invention provides an artificial hair fiber,

[0008] The present inventors have conducted extensive research and have found that in artificial hair fibers containing a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, by adjusting the blending amount of the chlorinated polyvinyl chloride resin with a specific chlorine content and by adjusting the storage modulus E' of the artificial hair fiber, artificial hair fibers having an appropriate thermal shrinkage rate can be obtained, leading to the completion of the present invention.

[0009] Various embodiments of the present invention are exemplified below. The embodiments shown below can be combined with each other. [1] An artificial hair fiber containing a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, wherein the chlorinated polyvinyl chloride resin contains a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 68.0% by mass, and the artificial hair fiber contains 5 to 30 parts by mass of the first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 67.0% by mass per 100 parts by mass of the polyvinyl chloride resin, and the artificial hair fiber has a storage modulus E' at 105°C of 1.5 x 10 in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ [2] An artificial hair fiber comprising a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, wherein the artificial hair fiber has a chlorine content of 57.5 to 58.9% by mass relative to 100% by mass of the total of the polyvinyl chloride resin and the chlorinated polyvinyl chloride resin, and the artificial hair fiber has a storage modulus E' at 105°C of 1.5 x 10 in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７[3] The artificial hair fiber has a storage modulus E' of 1.0 x 10 at 115°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~2.5 x 10 ７ [4] The fiber for artificial hair according to any one of [1] to [3], which contains 1 to 10 parts by mass of a second chlorinated polyvinyl chloride resin having a chlorine content of 59.0% by mass or more and less than 64.0% by mass relative to 100 parts by mass of the polyvinyl chloride resin. [5] The chlorinated polyvinyl chloride resin has a storage modulus E' at 105°C of 1.0 x 10 in dynamic viscoelasticity measurement at a frequency of 1 Hz. ６ ~1.0 x 10 ９ [6] A hair accessory comprising the artificial hair fiber according to any one of [1] to [5]. [7] A method for producing an artificial hair fiber, the method comprising a step of preparing a resin composition for an artificial hair fiber and a spinning step, wherein in the step of preparing a resin composition for an artificial hair fiber, raw materials containing a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin are mixed to obtain a resin composition for an artificial hair fiber, the raw materials containing 5 to 30 parts by mass of a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 67.0% by mass per 100 parts by mass of the polyvinyl chloride resin, and in the spinning step, the resin composition for an artificial hair fiber is melt-spun to obtain the artificial hair fiber, and the artificial hair fiber has a storage modulus E' at 105°C of 1.5 x 10 in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ [8] The production method according to [7], further comprising a chlorinated polyvinyl chloride resin preparation step, in which a polyvinyl chloride resin is chlorinated by a thermal chlorination method to obtain the chlorinated polyvinyl chloride resin.

[0010] The artificial hair fiber according to the present invention has a moderate heat shrinkage rate. Furthermore, by using the artificial hair fiber according to the present invention, hair accessories can be obtained that include the artificial hair fiber having a moderate heat shrinkage rate. Since the artificial hair fiber according to the present invention has a heat shrinkage rate within a specific range at a specific temperature, it can form a natural curl shape. Furthermore, by using the method for producing the artificial hair fiber according to the present invention, it is possible to obtain artificial hair fiber having a moderate heat shrinkage rate.

[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 Fiber According to the First Embodiment 1.1 Artificial Hair Fiber The artificial hair fiber according to the first embodiment of the present invention comprises a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin. The chlorinated polyvinyl chloride resin according to the first embodiment of the present invention comprises a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 68.0% by mass, and the artificial hair fiber comprises 5 to 30 parts by mass of the first chlorinated polyvinyl chloride resin per 100 parts by mass of the polyvinyl chloride resin. Furthermore, the artificial hair fiber has a storage modulus E' at 105°C of 1.5 x 10 in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ is.

[0013] 1.1.1 Polyvinyl Chloride Resin The polyvinyl chloride resin according to the present invention may comprise a vinyl chloride polymer containing monomer units (vinyl chloride monomer units) derived from vinyl chloride monomer. The polyvinyl chloride resin according to the present invention may comprise a homopolymer obtained by homopolymerizing vinyl chloride monomer and / or a copolymer containing monomer units derived from vinyl chloride monomer and another monomer copolymerizable with 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.

[0014] The polyvinyl chloride resin according to the present invention may be primarily composed of vinyl chloride monomer units and may contain 70% by weight or more of vinyl chloride monomer units relative to 100% by weight of the polyvinyl chloride resin. The content of vinyl chloride monomer units may be, for example, 70, 75, 80, 85, 90, 95, or 100% by weight, or may be within a range between any two of the values ​​exemplified here. The polyvinyl chloride resin according to one embodiment of the present invention may be composed of vinyl chloride monomer units, i.e., may be a homopolymer of one or more vinyl chlorides.

[0015] The polyvinyl chloride resin according to the present invention refers to a polyvinyl chloride resin that has not been chlorinated. The polyvinyl chloride resin according to the present invention may have a chlorine content of 58% by mass or less, and may be 56 to 58% by mass. The chlorine content of the polyvinyl chloride resin may be, for example, 56.0, 56.1, 56.2, 56.3, 56.4, 56.5, 56.6, 56.7, 56.8, 56.9, 57.0, 57.1, 57.2, 57.3, 57.4, 57.5, 57.6, 57.7, 57.8, 57.9, or 58.0% by mass, or may be within a range between any two of the values ​​exemplified here.

[0016] The average degree of polymerization of the polyvinyl chloride resin according to one embodiment of the present invention can be 500 to 1500. The average degree of polymerization is, for example, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, or 1500, and may be within a range between any two of the values ​​exemplified here. The average degree of polymerization can be calculated in accordance with JIS K6720-2:1999 by dissolving 200 mg of polyvinyl chloride resin in 50 mL of nitrobenzene, measuring the specific viscosity of the resulting polymer solution using an Ubbelohde viscometer in a thermostatic bath at 30°C.

[0017] The polyvinyl chloride resin according to one embodiment of the present invention has a storage modulus E' of 1.0 x 10 at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ６ ~5.0 x 10 ８ The storage modulus E' can be, for example, 1.0 x 10 ６ , 2.0 × 10 ６ , 5.0 × 10 ６ , 1.0×10 ７ , 2.0 × 10 ７ , 5.0 × 10 ７ , 1.0×10 ８ , 2.0 × 10 ８ , 5.0 × 10 ８ and may be within a range between any two of the values ​​exemplified herein. The storage modulus E' of a polyvinyl chloride resin can be determined by preparing a sheet-like sample using the polyvinyl chloride resin and measuring the dynamic viscoelasticity of the sheet-like sample using a dynamic viscoelasticity measuring device. Specifically, it can be determined by the method described in the examples.

[0018] 1.1.2 Chlorinated Polyvinyl Chloride Resin The chlorinated polyvinyl chloride resin according to the present invention refers to a polyvinyl chloride resin that has been subjected to a chlorination treatment. The chlorinated polyvinyl chloride resin can have a higher chlorine content than the polyvinyl chloride resin before chlorination. Examples of the polyvinyl chloride resin before chlorination include the polyvinyl chloride resins described above. The chlorinated polyvinyl chloride resin according to the present invention can be composed of one type of chlorinated vinyl chloride polymer, or can contain two or more types of chlorinated vinyl chloride polymers. The chlorinated polyvinyl chloride resin can have a chlorine content of more than 58% by mass, preferably 59% by mass or more. The chlorine content of the chlorinated polyvinyl chloride resin according to one embodiment of the present invention is, for example, 59.0, 59.5, 60.0, 60.5, 61.0, 61.5, 62.0, 62.5, 63.0, 63.5, 64.0, 64.5, 65.0, 65.5, 66.0, 66.5, 67.0, 67.5, or 68.0 mass%, and may be within a range between any two of the numerical values ​​exemplified here.

[0019] The chlorinated polyvinyl chloride resin according to the first embodiment includes a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 68.0 mass %. The chlorine content of the first chlorinated polyvinyl chloride resin is, for example, 64.0, 64.1, 64.2, 64.3, 64.4, 64.5, 64.6, 64.7, 64.8, 64.9, 65.0, 65.1, 65.2, 65.3, 65.4, 65.5, 65.6, 65.7, 65.8, 65.9, 66.0, 66.1, 66.2, 66.3, 66.4, 66.5, 66.6, 66.7, 66.8, 66.9, 67.0, 67.1, 67.2, 67.3, 67.4, 67.5, 67.6, 67.7, 67.8, 67.9, or 68.0% by mass, and may be within a range between any two of the values ​​exemplified here.

[0020] The average degree of polymerization of the first chlorinated polyvinyl chloride resin can be 300 to 1000. The average degree of polymerization is, for example, 300, 400, 500, 600, 700, 800, 900, or 1000, and may be within a range between any two of the values ​​exemplified here.

[0021] The storage modulus E' of the first chlorinated polyvinyl chloride resin at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz was 1.0 x 10 ９ The following can be obtained: 1.0 × 10 ９ It can be less than 1.0 × 10 ８ ~1.0 x 10 ９ This gives 1.0 x 10 ８ Above 1.0 x 10 ９ It can be less than 1.0 × 10 ８ ~9.9 x 10 ９ The storage modulus E' can be, for example, 1.0 x 10 ８ , 2.0 × 10 ８ , 3.0 × 10 ８ , 4.0 × 10 ８ , 5.0 × 10 ８ , 6.0 × 10 ８ , 7.0 × 10 ８ , 8.0 × 10 ８ , 9.0 × 10 ８ , 9.5 x 10 ８ , 9.9 x 10 ８ , 1.0×10 ９ and may be in a range between any two of the values ​​given here.

[0022] The storage modulus E' of a chlorinated polyvinyl chloride resin can be determined by preparing a sheet-like sample from the chlorinated polyvinyl chloride resin and measuring the dynamic viscoelasticity of the sheet-like sample using a dynamic viscoelasticity measuring device. Specifically, it can be determined by the method described in the Examples. The storage modulus E' of a chlorinated polyvinyl chloride resin can be controlled by adjusting the production conditions of the chlorinated polyvinyl chloride resin. For example, the storage modulus E' can be adjusted by adjusting the chlorine content or by appropriately selecting the chlorination method. Specifically, by selecting thermal chlorination as the chlorination method, a chlorinated polyvinyl chloride having a storage modulus E' within the above-mentioned numerical range can be more easily obtained. The first chlorinated polyvinyl chloride resin can be a chlorinated polyvinyl chloride resin obtained by a thermal chlorination method.

[0023] The chlorinated polyvinyl chloride resin according to the first embodiment contains 5 to 30 parts by mass of the first chlorinated polyvinyl chloride resin relative to 100 parts by mass of the polyvinyl chloride resin. The content of the first chlorinated polyvinyl chloride resin is, for example, 5, 10, 15, 20, 25, or 30 parts by mass, and may be within a range between any two of the numerical values ​​exemplified here.

[0024] The chlorinated polyvinyl chloride resin according to one embodiment of the present invention may contain a second chlorinated polyvinyl chloride resin having a chlorine content of 59.0% by mass or more and less than 64.0% by mass. The chlorine content of the second chlorinated polyvinyl chloride resin may be, for example, 59.0, 59.1, 59.2, 59.3, 59.4, 59.5, 59.6, 59.7, 59.8, 59.9, 60.0, 60.1, 60.2, 60.3, 60.4, 60.5, 60.6, 60.7, 60.8, 60.9, 61.0, 61.1, 61.2, 61.3, 61.4, 61.5 , 61.6, 61.7, 61.8, 61.9, 62.0, 62.1, 62.2, 62.3, 62.4, 62.5, 62.6, 62.7, 62.8, 62.9, 63.0, 63.1, 63.2, 63.3, 63.4, 63.5, 63.6, 63.7, 63.8, 63.9 mass%, and may be within a range between any two of the numerical values ​​exemplified here.

[0025] The average degree of polymerization of the second chlorinated polyvinyl chloride resin can be 300 to 1000. The average degree of polymerization is, for example, 300, 400, 500, 600, 700, 800, 900, or 1000, and may be within a range between any two of the values ​​exemplified here.

[0026] The storage modulus E' of the second chlorinated polyvinyl chloride resin at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz was 1.0 x 10 ６ ~5.0 x 10 ８ This gives 1.0 x 10 ７ ~5.0 x 10 ８ This gives 1.0 x 10 ７ Super 1.0×10 ８ The following can be obtained: 1.0 × 10 ７ Super 1.0×10 ８ The storage modulus E' can be, for example, less than 1.0 x 10 ６ , 2.0 × 10６ , 5.0 × 10 ６ , 1.0×10 ７ , 1.1 × 10 ７ , 2.0 × 10 ７ , 5.0 × 10 ７ , 9.9 x 10 ８ , 1.0×10 ８ , 2.0 × 10 ８ , 5.0 × 10 ８ and may be within a range between any two of the numerical values ​​exemplified here. The second chlorinated polyvinyl chloride resin may be a chlorinated polyvinyl chloride resin obtained by a thermal chlorination method.

[0027] The chlorinated polyvinyl chloride resin according to one embodiment of the present invention may include 1 to 10 parts by weight of the second chlorinated polyvinyl chloride resin relative to 100 parts by weight of the polyvinyl chloride resin. The content of the second chlorinated polyvinyl chloride resin may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by weight, or may be within a range between any two of the values ​​exemplified here.

[0028] The chlorinated polyvinyl chloride resin according to one embodiment of the present invention has a storage modulus E' of 1.0 x 10 at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ６ ~1.0 x 10 ９ The chlorinated polyvinyl chloride resin may contain a chlorinated polyvinyl chloride resin having a molecular weight of 1.0×10 ６ That's it, 1.0 x 10 ９ It is preferable that the resin contains a chlorinated polyvinyl chloride resin having a molecular weight of less than 1.0×10 ７ Super, 1.0×10 ９ The chlorinated polyvinyl chloride resin according to one embodiment of the present invention preferably contains a chlorinated polyvinyl chloride resin having a storage modulus E′ of less than 1.0×10 ９ Preferably, the first chlorinated polyvinyl chloride resin has a storage modulus E′ of 1.0×10 or less. ８ That's it, 1.0 x 10 ９ and the storage modulus E′ is preferably less than 1.0×10 ８ ~9.9 x 10 ８The chlorinated polyvinyl chloride resin according to one embodiment of the present invention further comprises a first chlorinated polyvinyl chloride resin having a storage modulus E′ of 1.0×10 ６ ~5.0 x 10 ８ It is more preferable that the second chlorinated polyvinyl chloride resin contains a second chlorinated polyvinyl chloride resin having the formula:

[0029] The chlorinated polyvinyl chloride resin according to one embodiment of the present invention preferably contains a chlorinated polyvinyl chloride resin obtained by a thermal chlorination method. The chlorinated polyvinyl chloride resin according to one embodiment of the present invention preferably contains a first chlorinated polyvinyl chloride resin obtained by a thermal chlorination method, and more preferably contains a first chlorinated polyvinyl chloride resin obtained by a thermal chlorination method and a second chlorinated polyvinyl chloride resin obtained by a thermal chlorination method.

[0030] The storage modulus E' of the chlorinated polyvinyl chloride resin (which may contain a plurality of chlorinated polyvinyl chloride resins) according to one embodiment of the present invention is 1.0 × 10 ９ The following can be obtained: 1.0 × 10 ９ The storage modulus E' can be, for example, less than 1.0 x 10 ６ , 2.0 × 10 ６ , 5.0 × 10 ６ , 1.0×10 ７ , 2.0 × 10 ７ , 5.0 × 10 ７ , 1.0×10 ８ , 2.0 × 10 ８ , 3.0 × 10 ８ , 4.0 × 10 ８ , 5.0 × 10 ８ , 6.0 × 10 ８ , 7.0 × 10 ８ , 8.0 × 10 ８ , 9.0 x 10 ８ , 9.9 x 10 ８ , 1.0×10 ９ and may be in a range between any two of the values ​​given here.

[0031] 1.1.3 Other Components The artificial hair fiber according to one embodiment of the present invention may contain other components as needed, such as antistatic agents, heat stabilizers, lubricants, and colorants.

[0032] The antistatic agent may be a cationic, anionic, or amphoteric agent. The amount of the antistatic agent to be added is preferably in the range of 0.01 to 1 part by mass per 100 parts by mass of the polyvinyl chloride resin. By adjusting the amount of the antistatic agent to fall within this range, static electricity generation is suppressed, making it less likely for thread breakage to occur during the manufacturing process of the artificial hair fiber.

[0033] Conventional heat stabilizers can be used. Among these, it is desirable to use one or more selected from Ca-Zn-based heat stabilizers, hydrotalcite-based heat stabilizers, tin-based heat stabilizers, and epoxy-based heat stabilizers. Heat stabilizers are used to prevent thermal decomposition during molding, improve long-run properties, and improve the color tone of the filaments. A combination of Ca-Zn-based heat stabilizers and hydrotalcite-based heat stabilizers is particularly preferred, as they offer an excellent balance between molding processability and yarn properties. The blending amount of these heat stabilizers is preferably 0.1 to 5.0 parts by mass per 100 parts by mass of polyvinyl chloride resin. By adjusting the blending amount of the heat stabilizer within this range, thermal degradation of the resulting artificial hair fiber is suppressed, making it less susceptible to yellowing. Hydrotalcite-based heat stabilizers are specifically hydrotalcite compounds, and more specifically, complex salt compounds composed of magnesium and / or alkali metals and aluminum, or complex salt compounds composed of zinc, magnesium, and aluminum, with the water of crystallization removed. The hydrotalcite compound may be a natural product or a synthetic product, and the synthetic product may be synthesized by a conventionally known method.

[0034] Among the heat stabilizers, examples of Ca-Zn-based heat stabilizers include zinc stearate, calcium stearate, zinc 12-hydroxystearate, and calcium 12-hydroxystearate. Examples of hydrotalcite-based heat stabilizers include Alcamizer manufactured by Kyowa Chemical Industry Co., Ltd. Examples of tin-based heat stabilizers include mercaptotin-based heat stabilizers such as dimethyltin mercapto, dimethyltin mercaptide, dibutyltin mercapto, dioctyltin mercapto, dioctyltin mercapto polymer, and dioctyltin mercaptoacetate; maleate-tin-based heat stabilizers such as dimethyltin maleate, dibutyltin maleate, dioctyltin maleate, and dioctyltin maleate polymer; and laurate-tin-based heat stabilizers such as dimethyltin laurate, dibutyltin laurate, and dioctyltin laurate. Examples of epoxy-based heat stabilizers include epoxidized oils such as epoxidized soybean oil and epoxidized linseed oil. Examples of β-diketone-based heat stabilizers include stearoylbenzoylmethane (SBM) and dibenzoylmethane (DBM). The amount of these heat stabilizers added is preferably 0.2 to 10.0 parts by mass per 100 parts by mass of the polyvinyl chloride resin.

[0035] Conventional lubricants can be used as the lubricant. At least one lubricant selected from the group consisting of metal soap-based lubricants, hydrocarbon-based lubricants, higher fatty acid-based lubricants, ester-based lubricants, and higher alcohol-based lubricants is particularly preferred. The lubricant reduces friction with the metal surface of the processing machine and friction between resins, improving fluidity and processability. The amount of lubricant blended is preferably 0.2 to 5.0 parts by mass per 100 parts by mass of polyvinyl chloride resin. By adjusting the amount of lubricant blended within this range, the fluidity of the resin composition is improved, allowing for stable molding of the resin composition.

[0036] Examples of metal soap-based lubricants include metal soaps such as stearates, laurates, palmitates, and oleates of Na, Mg, Al, Ca, and Ba. Examples of hydrocarbon-based lubricants include polyethylene wax and polypropylene wax. 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. Examples of ester-based lubricants include ester-based lubricants composed of alcohols and fatty acids, pentaerythritol-based lubricants such as monoesters, diesters, triesters, and tetraesters of pentaerythritol or dipentaerythritol with higher fatty acids, and mixtures thereof, and montanic acid wax-based lubricants such as esters of montanic acid with higher alcohols such as stearyl alcohol, palmityl alcohol, myristyl alcohol, lauryl alcohol, and oleyl alcohol. Examples of higher alcohol lubricants include stearyl alcohol, palmityl alcohol, myristyl alcohol, lauryl alcohol, and oleyl alcohol.

[0037] The colorant is a pigment, a dye, or the like, and by incorporating the colorant, pre-colored fibers (so-called spun-dyed fibers) can be obtained. As the colorant, conventionally known colorants can be used, such as black colorants, red colorants, yellow colorants, and purple colorants, and one or more of these can be used. In one embodiment of the present invention, the colorant can be used in combination with a dispersant to enhance the dispersibility of the colorant in the resin. Examples of dispersants include montanic acid metal salts, montanic acid waxes, polyethylene waxes, and fluorine waxes.

[0038] In addition to the antistatic agent, known compounding agents may be added to the artificial hair fiber according to one embodiment of the present invention depending on the purpose, provided that the effects of the present invention are not impaired. Examples of such compounding agents include processing aids, plasticizers, reinforcing agents, ultraviolet absorbers, antioxidants, fillers, flame retardants, pigments, initial color improvers, conductivity imparting agents, fragrances, etc.

[0039] 1.1.4 Characteristics of Artificial Hair Fibers The artificial hair fibers according to the present invention have a storage modulus E' of 1.5 x 10 at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ is 1.5 × 10 ７ ~4.0 x 10 ７ The storage modulus E' at 105°C is preferably 1.5 × 10 ７ , 1.6 × 10 ７ , 1.7 × 10 ７ , 1.8 × 10 ７ , 1.9 × 10 ７ , 2.0 × 10 ７ , 2.1 × 10 ７ , 2.2 × 10 ７ , 2.3 × 10 ７ , 2.4 × 10 ７ , 2.5 × 10 ７ , 2.6 × 10 ７ , 2.7 × 10 ７ , 2.8 × 10 ７ , 2.9 × 10 ７ , 3.0 × 10 ７ , 3.1 × 10 ７ , 3.2 × 10 ７ , 3.3 × 10 ７ , 3.4 × 10 ７ , 3.5 × 10 ７ , 3.6 × 10 ７ , 3.7 × 10 ７ , 3.8 × 10 ７ , 3.9 × 10 ７ , 4.0 × 10 ７ , 4.1 × 10 ７ , 4.2 × 10 ７ , 4.3 × 10 ７ , 4.4 × 10 ７ , 4.5 × 10 ７ and may be in a range between any two of the values ​​given here.

[0040] The artificial hair fiber according to the present invention has a storage modulus E' of 1.0 x 10 at 115°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~2.5 x 10 ７ It is preferable that the ７ ~2.0 x 10 ７The storage modulus E' at 105°C is, for example, 1.0 × 10 ７ , 1.1 × 10 ７ , 1.2 × 10 ７ , 1.3 × 10 ７ , 1.4 × 10 ７ , 1.5 × 10 ７ , 1.6 × 10 ７ , 1.7 × 10 ７ , 1.8 × 10 ７ , 1.9 × 10 ７ , 2.0 × 10 ７ , 2.1 × 10 ７ , 2.2 × 10 ７ , 2.3 × 10 ７ , 2.4 × 10 ７ , 2.5 × 10 ７ and may be in a range between any two of the values ​​given here.

[0041] The storage modulus E' of the artificial hair fiber can be determined by extracting a specific number of fibers from the artificial hair fiber bundle to be analyzed, for example, a yarn bundle consisting of four fibers, and performing dynamic viscoelasticity measurement using a dynamic viscoelasticity measuring device. Specifically, the storage modulus E' can be determined by the method described in the Examples. The storage modulus E' of the artificial hair fiber can be adjusted by changing the type and amount of components such as resins contained in the resin composition for artificial hair fibers. As an example, it can be controlled by adjusting the type and amount of chlorinated polyvinyl chloride resin. The artificial hair fiber according to one embodiment of the present invention can be made to have an appropriate thermal shrinkage rate by adjusting the amount of the first chlorinated polyvinyl chloride resin contained in the artificial hair fiber and the storage modulus E' of the artificial hair fiber.

[0042] The artificial hair fiber according to one embodiment of the present invention preferably has a chlorine content of 57.5 to 58.9% by mass relative to 100% by mass of the total of the polyvinyl chloride resin and the chlorinated polyvinyl chloride resin. The chlorine content may be, for example, 57.5, 57.6, 57.7, 57.8, 57.9, 58, 58.1, 58.2, 58.3, 58.4, 58.5, 58.6, 58.7, 58.8, or 58.9% by mass, or may be within a range between any two of the values ​​exemplified here. The chlorine content of the artificial hair fiber can be analyzed by a combustion bomb method or a combustion flask method in accordance with JIS K 7385. By adjusting the chlorine content in the artificial hair fiber, the artificial hair fiber according to one embodiment of the present invention can be made to have a more appropriate thermal shrinkage rate.

[0043] The artificial hair fiber according to one embodiment of the present invention preferably has a heat shrinkage of 1.2 to 2.6% when heat treated at 90°C for 5 minutes, as calculated by the following formula (1): Heat shrinkage (%) = {(length before heat treatment) - (length after heat treatment)} / (length before heat treatment) x 100 (1) The heat shrinkage when heat treated at 90°C for 5 minutes is, for example, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, or 2.6%, and may be within a range between any two of the values ​​exemplified here.

[0044] The artificial hair fiber according to the present invention preferably has a heat shrinkage of 0.5% or less when heat treated at 80° C. for 5 minutes, as calculated by the above formula (1). The heat shrinkage when heat treated at 80° C. for 5 minutes is, for example, 0.0, 0.1, 0.2, 0.3, 0.4, or 0.5%, and may be within a range between any two of the values ​​exemplified here.

[0045] The artificial hair fiber according to the present invention preferably has a heat shrinkage of 3.6 to 4.8% calculated by the above formula (1) when heat treated at 100°C for 5 minutes. The heat shrinkage when heat treated at 100°C for 5 minutes is, for example, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, or 4.8%, and may be within a range between any two of the values ​​exemplified here.

[0046] The heat shrinkage can be measured specifically by the method described in the Examples. The heat shrinkage can be controlled by adjusting the production conditions of the artificial hair fiber, for example, by adjusting the type and amount of each component contained in the resin composition for artificial hair fiber, and by adjusting the storage modulus E' of the artificial hair fiber. The artificial hair fiber according to the present invention can form a natural curl shape by having a heat shrinkage within a specific numerical range at a specific temperature. For example, if the heat shrinkage is too small, it may not be possible to form a natural curl shape.

[0047] The artificial hair fiber according to the present invention preferably has a glossiness of 200 to 270. The glossiness may be, for example, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, or 270, or may be within a range between any two of the values ​​exemplified here. The glossiness can be measured using a goniophotometer, specifically, by the method described in the Examples. The glossiness can be controlled by adjusting the manufacturing conditions for the artificial hair fiber, for example, by adjusting the types and amounts of each component contained in the resin composition for artificial hair fiber.

[0048] 1.2 Method for producing artificial hair fibers A method for producing artificial hair fibers according to one embodiment of the present invention includes a step of preparing a resin composition for artificial hair fibers and a spinning step. In the step of preparing a resin composition for artificial hair fibers, raw materials including a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin are mixed to obtain a resin composition for artificial hair fibers, the raw materials including 5 to 30 parts by mass of a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 67.0% by mass per 100 parts by mass of the polyvinyl chloride resin. In the spinning step, the resin composition for artificial hair fibers is melt-spun to obtain artificial hair fibers, and the artificial hair fibers have a storage modulus E' of 1.5 x 10 at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ The method for producing artificial hair fibers according to one embodiment of the present invention may further include a step of preparing a chlorinated polyvinyl chloride resin.

[0049] 1.2.1 Chlorinated Polyvinyl Chloride Resin Preparation Step In the chlorinated polyvinyl chloride resin preparation step, a polyvinyl chloride resin can be obtained by chlorinating the polyvinyl chloride resin by photochlorination or thermal chlorination. In the chlorinated polyvinyl chloride resin preparation step according to one embodiment of the present invention, a polyvinyl chloride resin is preferably obtained by chlorinating the polyvinyl chloride resin by thermal chlorination. By using a resin composition containing a chlorinated polyvinyl chloride resin chlorinated by thermal chlorination, the storage modulus E' of the resulting artificial hair fiber can be more easily adjusted.

[0050] 1.2.2 Artificial Hair Fiber Resin Composition Preparation Step In the artificial hair fiber resin composition preparation step, raw materials including a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin are mixed to obtain a resin composition for artificial hair fibers. Here, the raw materials include a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, and may contain other components as needed. The other components may include the components listed above. The raw materials may contain 5 to 30 parts by mass of a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 67.0% by mass per 100 parts by mass of the polyvinyl chloride resin. The amount of the first chlorinated polyvinyl chloride resin added per 100 parts by mass of the polyvinyl chloride resin may be, for example, 5, 10, 15, 20, 25, or 30 parts by mass, or may be within a range between any two of the values ​​exemplified herein.

[0051] 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 known mixing devices such as a Henschel mixer, super mixer, or ribbon blender, and the powder compound can then be melt-mixed to obtain a pelleted 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 by setting the cut temperature during mixing to 105 to 155°C. The pellet compound can be produced by a method similar to that used to produce pellet compounds of general polyvinyl chloride resins. For example, pellet compounds can be produced using kneaders such as a single-screw extruder, a counter-rotating twin-screw extruder, a conical twin-screw extruder, a co-rotating twin-screw extruder, a co-kneader, a planetary gear extruder, or a 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 produce pellets. A means of removing chips (fine particles generated during pellet production) that may be mixed in during cold cutting can also be used. Since the cutter blades can chip and generate chips easily after prolonged use, it is recommended to replace them as needed.

[0052] 1.2.3 Spinning Process In the spinning process, 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 to melt-spin. Conventional extruders can be used as the extruder, including single-screw extruders, counter-rotating twin-screw extruders, and conical twin-screw extruders. Examples include single-screw extruders with a diameter of 35 to 85 mm and conical extruders with a bore of 35 to 50 mm. If the bore is too large, the extrusion rate will be high and the nozzle pressure will be excessive, which may increase the resin temperature and make it more susceptible to deterioration.

[0053] The melt spinning conditions can be set appropriately, and as an example, a nozzle with projections on three sides can be used, 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 can be selected so that the cross section of the resulting artificial hair fiber has the desired shape.

[0054] 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 can be taken up by a take-up machine installed directly below the nozzle (for example, about 4.5 m away).

[0055] In the artificial hair fiber according to one embodiment of the present invention, the number of thread breakages occurring during the spinning process until an undrawn thread is produced is preferably four or less times per hour, and more preferably less than one time per hour (not even once per hour).

[0056] 1.2.4 Drawing Step and Heat Treatment Step The method for producing artificial hair fiber according to one embodiment of the present invention may also include a drawing step and a heat treatment step. In the drawing step, the undrawn artificial hair fiber obtained in the melt spinning step described above is drawn using a drawing machine to obtain drawn artificial hair fiber. As an example, in the drawing step, the undrawn artificial hair fiber can be drawn 2 to 5 times at 90 to 110°C in an air atmosphere. Furthermore, in the heat treatment step, the drawn artificial hair fiber can be heat-treated using a heat treatment machine. As an example, in the heat treatment step, the drawn artificial hair fiber is heat-treated in an air atmosphere at 90 to 110°C to draw 0.5 to 3.0 times its original length, and then heat-shrunk until the entire fiber length is 75% of its pre-treatment length, thereby obtaining heat-treated artificial hair fiber with a fineness of 58 to 62 denier.

[0057] 1.2.5 Gear Processing Step The method for producing artificial hair fibers according to one embodiment of the present invention can also 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, and the number of gear fractions 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 account the fiber material and fineness. These processing conditions are not particularly limited, but as an example, the depth of the gear wave grooves can be 0.2 mm to 6 mm, preferably 0.5 mm to 5 mm, the gear surface temperature can be 30°C to 100°C, preferably 40°C to 80°C, and the processing speed can be 0.5 to 10 m / min, preferably 1.0 m / min to 8.0 m / min.

[0058] The total fineness of the fiber bundles used in gear processing is not particularly limited, but can be 100,000 to 2,000,000 decitex, preferably 500,000 to 1,500,000 decitex. By setting the total fineness of the fiber bundles at or above the lower limit, the productivity of gear processing can be increased and thread breakage during gear processing can be suppressed. On the other hand, by setting the total fineness of the fiber bundles at or below the lower limit, a more uniform wave shape can be obtained. In the present invention, artificial hair fibers include artificial hair fibers after spinning, and encompass artificial hair fibers before the drawing process, after the drawing process, before the heat treatment process, after the heat treatment process, before the gear processing process, and after the gear processing process.

[0059] 1.3 Artificial Hair Fiber Bundle and Hair Accessory An artificial hair fiber bundle according to one embodiment of the present invention includes the above-mentioned artificial hair fiber and can be made of the above-mentioned artificial hair fiber. A hair accessory according to one embodiment of the present invention comprises the above-mentioned artificial hair fiber. Furthermore, a hair accessory according to one embodiment of the present invention comprises the above-mentioned artificial hair fiber bundle.

[0060] The artificial hair fiber of the present invention can be used for hair accessories. Examples of hair accessories include wigs, hair pieces, braids, and hair extensions. Hair accessories obtained from the artificial hair fiber of the present invention have an appropriate heat shrinkage rate, are easy to form and maintain a desired style, and can exhibit effects similar to those of human hair.

[0061] 2. Artificial Hair Fiber According to a Second Embodiment The artificial hair fiber according to a second embodiment of the present invention comprises a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin. The artificial hair fiber according to the second embodiment of the present invention has a chlorine content of 57.5 to 58.9% by mass relative to 100% by mass of the polyvinyl chloride resin and the chlorinated polyvinyl chloride resin combined, and the artificial hair fiber has a storage modulus E' of 1.5 x 10 at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ The following description will focus on the differences from the artificial hair fiber according to the first embodiment.

[0062] 2.1.1 Polyvinyl chloride resin As the polyvinyl chloride resin, the polyvinyl chloride resin described in the first embodiment can be used.

[0063] 2.1.2 Chlorinated Polyvinyl Chloride Resin As the polyvinyl chloride resin, the chlorinated polyvinyl chloride resin described in the first embodiment can be used.

[0064] The chlorinated polyvinyl chloride resin according to the second embodiment can include a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 68.0 mass %. The chlorine content of the first chlorinated polyvinyl chloride resin is, for example, 64.0, 64.1, 64.2, 64.3, 64.4, 64.5, 64.6, 64.7, 64.8, 64.9, 65.0, 65.1, 65.2, 65.3, 65.4, 65.5, 65.6, 65.7, 65.8, 65.9, 66.0, 66.1, 66.2, 66.3, 66.4, 66.5, 66.6, 66.7, 66.8, 66.9, 67.0, 67.1, 67.2, 67.3, 67.4, 67.5, 67.6, 67.7, 67.8, 67.9, or 68.0% by mass, and may be within a range between any two of the values ​​exemplified here. As the first chlorinated polyvinyl chloride resin, the first chlorinated polyvinyl chloride resin described in the first embodiment can be used.

[0065] The chlorinated polyvinyl chloride resin according to the second embodiment may contain 5 to 30 parts by mass of the first chlorinated polyvinyl chloride resin relative to 100 parts by mass of the polyvinyl chloride resin. The content of the first chlorinated polyvinyl chloride resin may be, for example, 5, 10, 15, 20, 25, or 30 parts by mass, or may be within a range between any two of the values ​​exemplified here.

[0066] The chlorinated polyvinyl chloride resin according to the second embodiment may contain a second chlorinated polyvinyl chloride resin having a chlorine content of 59.0 mass % or more and less than 64.0 mass %. As the second chlorinated polyvinyl chloride resin, the second chlorinated polyvinyl chloride resin described in the first embodiment can be used.

[0067] The chlorinated polyvinyl chloride resin according to the second embodiment may contain 1 to 10 parts by mass of the second chlorinated polyvinyl chloride resin relative to 100 parts by mass of the polyvinyl chloride resin. The content of the second chlorinated polyvinyl chloride resin may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10% by mass, and may be within a range between any two of the values ​​exemplified here.

[0068] Other aspects of the chlorinated polyvinyl chloride resin are as described in the first embodiment.

[0069] 2.1.3 Other Components As the other components, the other components described in the first embodiment can be used.

[0070] 2.1.4 Characteristics of Artificial Hair Fiber The artificial hair fiber according to the second embodiment has a chlorine content of 57.5 to 58.9% by mass relative to 100% by mass of the total of the polyvinyl chloride resin and the chlorinated polyvinyl chloride resin. The chlorine content may be, for example, 57.5, 57.6, 57.7, 57.8, 57.9, 58, 58.1, 58.2, 58.3, 58.4, 58.5, 58.6, 58.7, 58.8, or 58.9% by mass, or may be within a range between any two of the values ​​exemplified here. Analysis can be performed using a combustion bomb method or a combustion flask method in accordance with JIS K 7385.

[0071] The storage modulus E', heat shrinkage, and gloss of the artificial hair fiber measured by dynamic viscoelasticity at a frequency of 1 Hz are as described in Embodiment 1. The artificial hair fiber according to one embodiment of the present invention can be made to have an appropriate heat shrinkage by adjusting the chlorine content and storage modulus E' in the artificial hair fiber.

[0072] 2.2 Method for producing artificial hair fibers A method for producing artificial hair fibers according to one embodiment of the present invention includes a step of preparing a resin composition for artificial hair fibers and a spinning step. In the step of preparing a resin composition for artificial hair fibers, raw materials including a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin are mixed to obtain a resin composition for artificial hair fibers, the raw materials having a chlorine content of 57.5 to 58.9 mass% relative to 100 mass% of the total of the polyvinyl chloride resin and the chlorinated polyvinyl chloride resin. In the spinning step, the resin composition for artificial hair fibers is melt-spun to obtain the artificial hair fibers, and the artificial hair fibers have a storage modulus E' of 1.5 x 10 at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ The method for producing artificial hair fibers according to one embodiment of the present invention may further include a step of preparing a chlorinated polyvinyl chloride resin.

[0073] 2.2.1 Chlorinated Polyvinyl Chloride Resin Preparation Step The chlorinated polyvinyl chloride resin preparation step is as described in the first embodiment.

[0074] 2.2.2 Artificial Hair Fiber Resin Composition Preparation Process In the artificial hair fiber resin composition preparation process, raw materials including a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin are mixed to obtain a resin composition for artificial hair fibers. Here, the raw materials include a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, and may contain other components as needed. Examples of other components include those listed above. The raw materials have a chlorine content of 57.5 to 58.9 mass% relative to 100 mass% of the total of the polyvinyl chloride resin and the chlorinated polyvinyl chloride resin. The chlorine content may be, for example, 57.5, 57.6, 57.7, 57.8, 57.9, 58, 58.1, 58.2, 58.3, 58.4, 58.5, 58.6, 58.7, 58.8, or 58.9 mass%, or may be within a range between any two of the values ​​listed here.

[0075] The mixing method and other aspects are the same as those described in the first embodiment.

[0076] 2.2.3 Spinning, Drawing, and Heat Treatment Steps, and Gear Machining Step The spinning, drawing, and heat treatment steps, and the gear machining step are as described in the first embodiment.

[0077] 2.3 Artificial Hair Fiber Bundle and Hair Accessory The aspects of the artificial hair fiber bundle and hair accessory according to this embodiment are as explained in the first embodiment.

[0078] 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.

[0079] Example 1 100 parts by mass of polyvinyl chloride resin (manufactured by Taiyo Vinyl Corporation, product name: TH1000), 12.6 parts by mass of chlorinated polyvinyl chloride resin (manufactured by Sekisui Chemical Co., Ltd., product name: HA-24K), and 4.9 parts by mass of chlorinated polyvinyl chloride resin (manufactured by Sekisui Chemical Co., Ltd., product name: HA-17E) were mixed in a blender. The blended materials were kneaded using a single-screw extruder to obtain resin composition 1 for artificial hair fibers in the form of pellets for spinning.

[0080] The obtained resin composition for artificial hair fibers in pellet form was spun in a φ40 mm single-screw melt spinning machine. The molten resin was discharged from 100 dies with a hole diameter of 0.5 mm and cooled in a water bath at approximately 30°C. The discharge rate and winding speed were adjusted to produce undrawn yarn. The temperature setting of the φ40 mm melt spinning machine was set to 140 to 180°C.

[0081] The obtained undrawn yarn was drawn at 100°C and then annealed at 150°C to 200°C to obtain artificial hair fiber 1. The draw ratio was 3 times, and the relaxation rate during annealing was 0.5 to 3%. The relaxation rate during annealing is a value calculated by (rotational speed of the take-up roller during annealing) / (rotational speed of the delivery roller during annealing).

[0082] (Examples 2 to 7, Comparative Examples 1 to 7) Resin compositions for artificial hair fibers 2 to 14 were prepared in the same manner as in Example 1, except that the formulations of the resin compositions for artificial hair fibers were as shown in Table 1. Melt spinning was also carried out in the same manner as in Example 1, to obtain artificial hair fibers 2 to 14.

[0083] The materials used in Tables 1 and 2 were as follows. The chlorine content in the resin composition for artificial hair fibers was calculated from the chlorine content of each resin and the amount of each resin contained in each resin composition for artificial hair fibers. <Polyvinyl chloride resin> TH-1000: manufactured by Taiyo Vinyl Corporation, product name: TH1000, chlorine content: 56.8% by mass, average degree of polymerization: 1000, storage modulus E' at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz: 1.0 x 10 ７ <Chlorinated polyvinyl chloride resin> HA-24K: Sekisui Chemical Co., Ltd., product name: HA-24K, chlorine content: 66.6% by mass, average degree of polymerization: 700, storage modulus E′ at 105° C. in dynamic viscoelasticity measurement at a frequency of 1 Hz: 1.0×10 ９ HA-27H: Sekisui Chemical Co., Ltd., Product name: HA-27H, Chlorine content: 65.6% by mass, Average degree of polymerization: 700, Storage modulus E' at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz: 8.0 × 10 ８ HA-27K: Sekisui Chemical Co., Ltd., product name: HA-27K, chlorine content: 66.5% by mass, average degree of polymerization: 700, storage modulus E' at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz: 7.0 x 10 ８ HA-17F: Sekisui Chemical Co., Ltd., Product name: HA-17F, Chlorine content: 64.8% by mass, Average degree of polymerization: 600, Storage modulus E' at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz: 5.0 × 10 ８ HA-15E: Sekisui Chemical Co., Ltd., Product name: HA-15E, Chlorine content: 62.1% by mass, Average degree of polymerization: 600, Storage modulus E' at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz: 1.0 x 10 ７ HA-17E: Sekisui Chemical Co., Ltd., Product name: HA-17E, Chlorine content: 62.0% by mass, Average degree of polymerization: 600, Storage modulus E' at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz: 1.0 x 10 ７ , chlorinated by thermal chlorination method

[0084] (Evaluation of Polyvinyl Chloride Resin and Chlorinated Polyvinyl Chloride Resin) The storage modulus E' of the polyvinyl chloride resin and chlorinated polyvinyl chloride resin used in each of the Examples and Comparative Examples was evaluated.

[0085] <Storage Modulus E'> Each of the polyvinyl chloride resins and chlorinated polyvinyl chloride resins used in the Examples and Comparative Examples was pressed into a sheet sample having a thickness of 0.5 mm using a heating press (Mini Test Press MP-WCL, manufactured by Toyo Seiki Seisaku-Sho, Ltd.) under conditions of a temperature of 200°C, a pressing time of 40 seconds, a pressure of 17 MPa, and a pressing area of ​​100 mm x 80 mm.

[0086] The dynamic viscoelasticity of the sheet sample was measured using a dynamic viscoelasticity measuring device (RSA-G2, manufactured by TA Instruments) to obtain the storage modulus E'. The measurement conditions were a temperature rise rate of 1°C / min, a chuck distance of 10 mm, a frequency of 1 Hz, and a measurement temperature range of 25 to 150°C.

[0087] (Evaluation of artificial hair fibers) The obtained artificial hair fibers were evaluated by the following method. <Spinnability> In the melt spinning process, the occurrence of thread breakage was visually observed until an undrawn thread was produced, and evaluated according to the following criteria: ○: Less than 1 thread breakage / hour (no thread breakage occurred within 1 hour) △: 1 to 4 thread breakages / hour ×: 5 or more thread breakages / hour

[0088] <Storage modulus E'> Four artificial hair fibers were taken out from a fiber bundle made of the artificial hair fibers according to the Examples and Comparative Examples. Next, the four fibers were lined up in a state where adjacent fibers were in contact with each other and fixed with a jig, and then the dynamic viscoelasticity of the yarn bundle made of the four fibers was measured using a dynamic viscoelasticity measuring device (manufactured by TA Instruments, RSA-G2) to obtain the storage modulus E'. The measurement conditions were a temperature rise rate of 1°C / min, a chuck distance of 10 mm, a frequency of 1 Hz, and a measurement temperature range of 25 to 150°C.

[0089] <Heat shrinkage rate> The artificial hair fibers (before crimping) according to the Examples and Comparative Examples, each having a length of 100 mm, were heat-treated in a gear oven at 80, 90, and 100°C for 5 minutes, and the fiber lengths before and after the heat treatment were measured, and the heat shrinkage rate was calculated based on the following formula (1): Heat shrinkage rate (%) = {(length before heat treatment) - (length after heat treatment)} / (length before heat treatment) x 100 (1)

[0090] <Glossiness> The glossiness of the artificial hair fibers of each Example and Comparative Example was measured using the following device and conditions: Device: Goniophotometer GP-700 manufactured by Murakami Color Research Laboratory Inc. Incident angle: 45° Sensitivity adjustment dial value (COARSE): 718 Sensitivity adjustment dial value (FINE): 737

[0091]

[0092]

Claims

1. An artificial hair fiber comprising a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, wherein the chlorinated polyvinyl chloride resin comprises a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 68.0% by mass, the artificial hair fiber comprises 5 to 30 parts by mass of the first chlorinated polyvinyl chloride resin per 100 parts by mass of the polyvinyl chloride resin, and the artificial hair fiber has a storage modulus E' at 105°C of 1.5 x 10 in a dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ That is, fibers for artificial hair.

2. An artificial hair fiber containing a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin, the artificial hair fiber having a chlorine content of 57.5 to 58.9% by mass relative to 100% by mass of the total of the polyvinyl chloride resin and the chlorinated polyvinyl chloride resin, and the artificial hair fiber having a storage modulus E' at 105°C of 1.5 x 10 in a dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~4.5 x 10 ７ That is, fibers for artificial hair.

3. The artificial hair fiber has a storage modulus E' of 1.0 x 10 at 115°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ７ ~2.5 x 10 ７ 3. The fiber for artificial hair according to claim 1 or 2, wherein 4. The fiber for artificial hair according to claim 1 or 2, comprising 1 to 10 parts by mass of a second chlorinated polyvinyl chloride resin having a chlorine content of 59.0% by mass or more and less than 64.0% by mass per 100 parts by mass of the polyvinyl chloride resin.

5. The chlorinated polyvinyl chloride resin has a storage modulus E' of 1.0 x 10 at 105°C in dynamic viscoelasticity measurement at a frequency of 1 Hz. ６ ~1.0 x 10 ９ 3. The fiber for artificial hair according to claim 1 or 2, comprising a chlorinated polyvinyl chloride resin represented by the formula:

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

7. A method for producing fibers for artificial hair, comprising: a step of preparing a resin composition for fibers for artificial hair; and a spinning step; in the step of preparing a resin composition for fibers for artificial hair, raw materials containing a polyvinyl chloride resin and a chlorinated polyvinyl chloride resin are mixed to obtain a resin composition for fibers for artificial hair; the raw materials contain 5 to 30 parts by mass of a first chlorinated polyvinyl chloride resin having a chlorine content of 64.0 to 67.0% by mass relative to 100 parts by mass of the polyvinyl chloride resin; in the spinning step, the resin composition for fibers for artificial hair is melt-spun to obtain the fibers for artificial hair; and in a dynamic viscoelasticity measurement at a frequency of 1 Hz, the fibers for artificial hair have a storage modulus E' at 105°C of 1.5 x 10 ７ ~4.5 x 10 ７ The manufacturing method is as follows.

8. The method according to claim 7, further comprising a chlorinated polyvinyl chloride resin preparation step, in which a polyvinyl chloride resin is chlorinated by a thermal chlorination method to obtain the chlorinated polyvinyl chloride resin.

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