Fiber for artificial hair, fiber bundle for artificial hair, and hair decoration product

Abstract

The present invention pertains to fibers, for artificial hair, containing a vinyl chloride polymer and an aromatic vinyl polymer, and having a heat shrinkage rate at 100°C of at least 7%. The present invention also pertains to a fiber bundle, for artificial hair, comprising the fibers for artificial hair. The present invention further pertains to a hair decoration product comprising the fiber bundle for artificial hair.

Description

Technical Field

[0001] The present invention relates to fibers for artificial hair, fiber bundles for artificial hair, hair decoration products, and the like.

Background Art

[0002] Vinyl chloride polymer fibers obtained by spinning a vinyl chloride polymer are widely used as fibers for artificial hair that constitute hair decoration products because of their excellent flexibility. However, since the specific gravity of the vinyl chloride polymer is large, vinyl chloride polymer fibers are not suitable for styles that require volume in artificial hair applications. In order to reduce the specific gravity of vinyl chloride polymer fibers, a means of blending an aromatic vinyl polymer having a lower specific gravity than the vinyl chloride polymer has been proposed (see, for example, Patent Documents 1 and 2 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When obtaining a hair decoration product using fibers for artificial hair, the inventor conceived of improving the volume feeling by subjecting the fibers for artificial hair to gear processing to shrink them. However, when using fibers for artificial hair containing an aromatic vinyl polymer, there is a problem that the volume feeling may not be sufficiently improved, and the styles that can be produced are limited.

[0005] One aspect of the present invention provides a fiber for artificial hair capable of obtaining artificial hair excellent in volume (specific volume) by subjecting it to a gear processing treatment. Another aspect of the present invention provides a fiber bundle for artificial hair using the fiber for artificial hair. Another aspect of the present invention provides a hair decoration product using the fiber bundle for artificial hair.

Means for Solving the Problems

[0006] The present invention relates to the following [1] to [9] and the like in some aspects. [1] A fiber for artificial hair containing a vinyl chloride polymer and an aromatic vinyl polymer and having a heat shrinkage rate at 100 ° C of 7% or more. [2] The fiber for artificial hair according to [1], wherein the heat shrinkage rate is 7 to 25%. [3] The fiber for artificial hair according to [1] or [2], wherein the content of the vinyl chloride polymer is 60 to 95% by mass and the content of the aromatic vinyl polymer is 5 to 40% by mass. [4] The fiber for artificial hair according to any one of [1] to [3], wherein the aromatic vinyl polymer has a styrenic compound and (meth) acrylonitrile as monomer units. [5] The fiber for artificial hair according to [4], wherein the styrenic compound contains styrene. [6] The fiber for artificial hair according to [4] or [5], wherein the ratio of the monomer unit of the styrenic compound is 74 to 88% by mass and the ratio of the monomer unit of (meth) acrylonitrile is 12 to 26% by mass based on the whole aromatic vinyl polymer. [7] A fiber bundle for artificial hair comprising the fiber for artificial hair according to any one of [1] to [6]. [8] The fiber bundle for artificial hair according to [7], further comprising a fiber different from the fiber for artificial hair. [9] A hair decoration product comprising the fiber bundle for artificial hair according to [7] or [8].

Effects of the Invention

[0007] According to one aspect of the present invention, it is possible to provide a fiber for artificial hair capable of obtaining artificial hair excellent in volume (specific volume) by performing a gear processing treatment. According to another aspect of the present invention, it is possible to provide a fiber bundle for artificial hair using the fiber for artificial hair. According to another aspect of the present invention, it is possible to provide a hair decoration product using the fiber bundle for artificial hair. According to another aspect of the present invention, it is possible to provide an application of the fiber to artificial hair or its production. According to another aspect of the present invention, it is possible to provide an application of the fiber to a hair decoration product or its production.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

[0009] In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a numerical range at a certain step can be arbitrarily combined with the upper limit value or the lower limit value of a numerical range at another step. In the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. The materials exemplified in this specification can be used singly or in combination of two or more unless otherwise specified. The content of each component in the composition means the total amount of the plurality of substances corresponding to each component in the composition when there are a plurality of substances corresponding to each component in the composition. “(Meth)acrylonitrile” means at least one of acrylonitrile and the corresponding methacrylonitrile. The same applies to other similar expressions such as “(meth)acrylic acid”.

[0010] The fiber for artificial hair according to this embodiment contains a vinyl chloride polymer and an aromatic vinyl polymer (excluding polymers corresponding to the vinyl chloride polymer). The heat shrinkage rate of the fiber for artificial hair according to this embodiment at 100°C is 7% or more. The fiber for artificial hair according to this embodiment is composed of a resin composition (fibrous resin composition) containing a vinyl chloride polymer and an aromatic vinyl polymer and having a heat shrinkage rate of 7% or more at 100°C. The resin composition according to this embodiment is a resin composition for artificial hair containing a vinyl chloride polymer and an aromatic vinyl polymer and having a heat shrinkage rate of 7% or more at 100°C.

[0011] According to the fiber for artificial hair according to this embodiment, by applying a gear processing treatment, it is possible to obtain an artificial hair excellent in volume feeling (specific volume). For example, in the evaluation method described in the examples below, when the gear processing treatment (treatment in the length direction of the fiber, groove depth of the gear waveform: 2.5 mm, gear pitch: 2.5 mm, surface temperature: 90°C, processing speed: 1.0 m / min) is applied to the fiber for artificial hair, a specific volume exceeding 7.0 cc / g can be obtained. Since the heat shrinkage rate of the fiber containing a vinyl chloride polymer and an aromatic vinyl polymer is high, when the fiber is subjected to a gear processing treatment, the fiber is likely to shrink due to the surface temperature of the gear, so it is presumed that the volume feeling is improved. However, the factor contributing to the improvement of the volume feeling is not limited to this factor.

[0012] The gear processing treatment is a treatment for applying crimping by passing a fiber (fiber bundle, etc.) between two meshing high-temperature gears. In the gear processing treatment for the fiber for artificial hair according to this embodiment, the material of the gear, the gear waveform, the fractional part of the gear, etc. are not particularly limited. Although the wave shape of the crimp can change depending on the material of the fiber, the fineness, the pressure conditions between the gears, etc., in this embodiment, the wave shape of the crimp can be controlled by the groove depth of the gear waveform, the surface temperature of the gear, the processing speed, etc. There are no particular restrictions on these processing conditions, but the groove depth of the gear waveform may be 0.2 to 6 mm or 0.5 to 5 mm, the surface temperature of the gear may be 50 to 110°C or 60 to 100°C, and the processing speed may be 0.5 to 10 m / min or 1.0 to 8.0 m / min.

[0013] In conventional fibers for artificial hair, when the fiber is shrunk, the combability may decrease. On the other hand, according to one aspect of the fiber for artificial hair according to the present embodiment, it is possible to obtain excellent combability while obtaining an excellent volume feeling. For example, in the evaluation method described in the examples below, the resistance can be reduced to 300 gf or less (for example, 250 gf or less).

[0014] For fibers for artificial hair, it is required to suppress the fiber from being cut (thread breakage) during melt spinning or the like, and in some cases, it is required to have excellent spinnability. On the other hand, according to one aspect of the fiber for artificial hair according to the present embodiment, it is possible to obtain excellent spinnability. For example, in the evaluation method described in the examples below, the number of thread breakages can be suppressed to 3 times or less.

[0015] The heat shrinkage rate of the fiber for artificial hair according to the present embodiment at 100 °C is 7% or more from the viewpoint of obtaining an excellent volume feeling. The heat shrinkage rate may be 8% or more, 9% or more, 10% or more, 11% or more, 12% or more, 15% or more, 18% or more, 19% or more, 20% or more, 22% or more, 23% or more, 25% or more, or 28% or more from the viewpoint of easily obtaining an excellent volume feeling. The heat shrinkage rate may be 40% or less, 35% or less, 30% or less, 28% or less, 25% or less, 23% or less, 22% or less, 20% or less, 19% or less, 18% or less, 15% or less, 12% or less, 11% or less, 10% or less, 9% or less, or 8% or less from the viewpoint of easily obtaining excellent combability. From these viewpoints, the heat shrinkage rate may be 7 to 40%, 7 to 30%, 8 to 30%, 8 to 28%, 10 to 28%, 12 to 28%, 15 to 28%, 20 to 28%, 22 to 28%, 7 to 25%, 8 to 25%, 8 to 22%, 8 to 20%, 8 to 15%, 10 to 25%, 15 to 25%, or 20 to 25%.

[0016] The heat shrinkage rate of the fiber for artificial hair according to this embodiment at 100 °C can be measured by the method described in the examples below. The heat shrinkage rate can be adjusted by the heating temperature of the heat treatment after spinning (for example, the heat treatment after the stretching treatment) when obtaining the fiber for artificial hair; the type or content of the monomer unit of the vinyl chloride polymer; the type or content of the monomer unit of the aromatic vinyl polymer, etc. The inventor has found that the heat shrinkage rate tends to increase by reducing the heating temperature of the heat treatment, and has found that the heat shrinkage rate of the fiber for artificial hair obtained at a heating temperature of 120 °C as in the examples of Patent Documents 1 and 2 is not sufficiently high (see the comparative examples below). On the basis of this, it has been found that at a heating temperature of less than 120 °C (for example, 110 °C or less), it is easy to obtain a fiber for artificial hair with a large heat shrinkage rate.

[0017] The fiber for artificial hair according to this embodiment can be used to obtain artificial hair. The fiber for artificial hair according to this embodiment may be a fiber after the stretching treatment or may be an unstretched fiber.

[0018] The fineness per single fiber of the fiber for artificial hair according to this embodiment may be in the following range. The fineness per single fiber may be 10 decitex or more, 20 decitex or more, 30 decitex or more, 40 decitex or more, 50 decitex or more, or 60 decitex or more. The fineness per single fiber may be 100 decitex or less, 90 decitex or less, 80 decitex or less, 70 decitex or less, or 60 decitex or less. From these viewpoints, the fineness per single fiber may be 10 to 100 decitex, 30 to 90 decitex, or 50 to 70 decitex.

[0019] The fiber for artificial hair according to this embodiment contains a vinyl chloride polymer (for example, a vinyl chloride-based resin). The vinyl chloride polymer is a polymer having vinyl chloride as a monomer unit (a polymer having a structural unit derived from vinyl chloride). The vinyl chloride polymer may be a homopolymer of vinyl chloride or may be a copolymer of vinyl chloride. The copolymer of vinyl chloride is a polymer of vinyl chloride and another compound (a compound other than vinyl chloride).

[0020] Examples of vinyl chloride copolymers include copolymers of vinyl chloride and vinyl esters such as vinyl chloride-vinyl acetate copolymer and vinyl chloride-vinyl propionate copolymer; copolymers of vinyl chloride and acrylic esters such as vinyl chloride-butyl acrylate copolymer and vinyl chloride-2-ethylhexyl acrylate copolymer; copolymers of vinyl chloride and olefins such as vinyl chloride-ethylene copolymer and vinyl chloride-propylene copolymer; and vinyl chloride-acrylonitrile copolymer etc.

[0021] From the viewpoint of easily obtaining excellent volume feeling, comb-through property and spinnability, the vinyl chloride polymer may contain at least one selected from the group consisting of a homopolymer of vinyl chloride, a vinyl chloride-ethylene copolymer, and a vinyl chloride-vinyl acetate copolymer, and may contain a homopolymer of vinyl chloride.

[0022] The vinyl chloride polymer can be produced by emulsion polymerization, bulk polymerization, suspension polymerization, etc. From the viewpoint of initial colorability of fibers etc., the vinyl chloride polymer may be a polymer produced by suspension polymerization.

[0023] The content of the vinyl chloride polymer is more than 0% by mass and less than 100% by mass based on the total mass of the fibers for artificial hair, or the total amount of the vinyl chloride polymer and the aromatic vinyl polymer, and may be within the following ranges. From the viewpoint that an excellent volume feeling is easily obtained, the content of the vinyl chloride polymer may be 98% by mass or less, 96% by mass or less, 95% by mass or less, less than 95% by mass, 90% by mass or less, 85% by mass or less, 83% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, or 65% by mass or less. From the viewpoint that excellent combability and spinnability are easily obtained, the content of the vinyl chloride polymer may be 40% by mass or more, 45% by mass or more, 50% by mass or more, 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, 83% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, more than 95% by mass, or 96% by mass or more. From these viewpoints, the content of the vinyl chloride polymer may be 40 to 98% by mass, 50 to 96% by mass, 60 to 96% by mass, 65 to 96% by mass, 70 to 96% by mass, 60 to 95% by mass, 65 to 90% by mass, 65 to 80% by mass, or 65 to 70% by mass.

[0024] The fiber for artificial hair according to the present embodiment contains an aromatic vinyl polymer (for example, an aromatic vinyl resin). The aromatic vinyl polymer is a polymer having an aromatic vinyl compound as a monomer unit (a polymer having a structural unit derived from an aromatic vinyl compound). Examples of the aromatic vinyl compound include styrene compounds, vinyltoluene, vinylnaphthalene, vinylanthracene, and the like. The aromatic vinyl polymer may have a styrene compound as a monomer unit from the viewpoint that excellent volume feeling, combability, and spinnability are easily obtained.

[0025] The styrene compound may contain at least one selected from the group consisting of styrene and styrene derivatives. Examples of the styrene derivative include α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, chlorostyrene, and the like. The styrene compound may contain styrene from the viewpoint that excellent volume feeling, combability, and spinnability are easily obtained.

[0026] The aromatic vinyl polymer may be a homopolymer of an aromatic vinyl compound or may be a copolymer of an aromatic vinyl compound (for example, an aromatic vinyl copolymer resin). The aromatic vinyl copolymer may be a copolymer having a plurality of aromatic vinyl compounds as monomer units or may be a copolymer having an aromatic vinyl compound and a compound different from the aromatic vinyl compound as monomer units.

[0027] Examples of the compound different from the aromatic vinyl compound include (meth)acrylonitrile, vinyl compounds (excluding compounds corresponding to styrene compounds), maleic anhydride, and the like. Examples of the vinyl compound include (meth)acrylic acid; (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. The aromatic vinyl polymer does not have to have a (meth)acrylic acid ester as a monomer unit (it does not have to have at least one selected from the group consisting of acrylic acid esters and methacrylic acid esters as a monomer unit). As the aromatic vinyl polymer, it is possible to use a polymer that does not have vinyl chloride as a monomer unit, and it is possible to use a polymer that does not have a halogen-containing compound as a monomer unit.

[0028] From the viewpoint of easily obtaining excellent volume feeling, comb-through property, and spinnability, the aromatic vinyl polymer may have a styrene compound and (meth)acrylonitrile as monomer units (it may have a monomer unit of a styrene compound and at least one selected from the group consisting of a monomer unit of acrylonitrile and a monomer unit of methacrylonitrile), may have styrene and (meth)acrylonitrile as monomer units (it may have a monomer unit of styrene and at least one selected from the group consisting of a monomer unit of acrylonitrile and a monomer unit of methacrylonitrile), and may have styrene and acrylonitrile as monomer units.

[0029] The proportion of the monomer unit of the styrenic compound may be within the following ranges based on the whole of the aromatic vinyl polymer or based on the total amount of the monomer unit of the styrenic compound and the monomer unit of (meth)acrylonitrile (the total amount of the monomer unit of the styrenic compound, the monomer unit of acrylonitrile and the monomer unit of methacrylonitrile). From the viewpoint that an excellent volume feeling is easily obtained, the proportion of the monomer unit of the styrenic compound may be 50% by mass or more, more than 50% by mass, 60% by mass or more, more than 60% by mass, 65% by mass or more, 68% by mass or more, 69% by mass or more, more than 69% by mass, 70% by mass or more, more than 70% by mass, 74% by mass or more, 75% by mass or more, 80% by mass or more, 82% by mass or more, 85% by mass or more, more than 85% by mass, 86% by mass or more, or 90% by mass or more. From the viewpoint that excellent comb-through property and spinnability are easily obtained, the proportion of the monomer unit of the styrenic compound may be less than 100% by mass, 95% by mass or less, 90% by mass or less, 88% by mass or less, less than 88% by mass, 86% by mass or less, 85% by mass or less, less than 85% by mass, 82% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, less than 70% by mass, 69% by mass or less, less than 69% by mass, or 68% by mass or less. From these viewpoints, the proportion of the monomer unit of the styrenic compound may be 50% by mass or more and less than 100% by mass, 60 to 95% by mass, 68 to 90% by mass, 68 to 86% by mass, 68 to 82% by mass, 68 to 75% by mass, 68 to 70% by mass, 70 to 90% by mass, 75 to 90% by mass, 82 to 90% by mass, 86 to 90% by mass, 70 to 86% by mass, 70 to 82% by mass, 70 to 75% by mass, 75 to 86% by mass, 82 to 86% by mass, 75 to 82% by mass, 50 to 82% by mass, 60 to 82% by mass, 82 to 95% by mass, 74 to 88% by mass, 74% by mass or more and less than 88% by mass.

[0030] The proportion of the monomer unit of (meth)acrylonitrile (the proportion of the total amount of the monomer unit of acrylonitrile and the monomer unit of methacrylonitrile) may be in the following ranges based on the whole aromatic vinyl polymer or based on the total amount of the monomer unit of the styrene-based compound and the monomer unit of (meth)acrylonitrile (the total amount of the monomer unit of the styrene-based compound, the monomer unit of acrylonitrile, and the monomer unit of methacrylonitrile). From the viewpoint of easily obtaining excellent comb-through property and spinnability, the proportion of the monomer unit of (meth)acrylonitrile may be more than 0% by mass, 5% by mass or more, 10% by mass or more, 12% by mass or more, more than 12% by mass, 14% by mass or more, 15% by mass or more, more than 15% by mass, 18% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, more than 30% by mass, 31% by mass or more, more than 31% by mass, or 32% by mass or more. From the viewpoint of suppressing the color tone of the fiber for artificial hair, the proportion of the monomer unit of (meth)acrylonitrile may be 50% by mass or less, less than 50% by mass, 40% by mass or less, less than 40% by mass, 35% by mass or less, 32% by mass or less, 31% by mass or less, less than 31% by mass, 30% by mass or less, less than 30% by mass, 26% by mass or less, 25% by mass or less, 20% by mass or less, 18% by mass or less, 15% by mass or less, less than 15% by mass, 14% by mass or less, or 10% by mass or less. From these viewpoints, the proportion of the monomer unit of (meth)acrylonitrile may be more than 0% by mass and 50% by mass or less, 5 to 40% by mass, 10 to 32% by mass, 14 to 32% by mass, 18 to 32% by mass, 25 to 32% by mass, 30 to 32% by mass, 10 to 30% by mass, 10 to 25% by mass, 10 to 18% by mass, 10 to 14% by mass, 14 to 30% by mass, 18 to 30% by mass, 25 to 30% by mass, 14 to 25% by mass, 14 to 18% by mass, 18 to 25% by mass, 18 to 50% by mass, 18 to 40% by mass, 5 to 18% by mass, 12 to 26% by mass, or more than 12% by mass and 26% by mass or less.

[0031] The combination of the proportion of the monomer unit of the styrenic compound and the proportion of the monomer unit of (meth)acrylonitrile is arbitrary, and each of the proportion of the monomer unit of the styrenic compound and the proportion of the monomer unit of (meth)acrylonitrile may be within the above-mentioned respective ranges. For example, the aromatic vinyl polymer may be in a mode where, based on the whole of the aromatic vinyl polymer, or based on the total amount of the monomer unit of the styrenic compound and the monomer unit of (meth)acrylonitrile (the total amount of the monomer unit of the styrenic compound, the monomer unit of acrylonitrile and the monomer unit of methacrylonitrile), the proportion of the monomer unit of the styrenic compound is 50 to 95% by mass and the proportion of the monomer unit of (meth)acrylonitrile is 5 to 50% by mass, or in a mode where the proportion of the monomer unit of the styrenic compound is 68 to 90% by mass and the proportion of the monomer unit of (meth)acrylonitrile is 10 to 32% by mass, or in a mode where the proportion of the monomer unit of the styrenic compound is 74 to 88% by mass and the proportion of the monomer unit of (meth)acrylonitrile is 12 to 26% by mass.

[0032] In the aromatic vinyl polymer, the total amount of the monomer unit of the styrenic compound and the monomer unit of (meth)acrylonitrile (the total amount of the monomer unit of the styrenic compound, the monomer unit of acrylonitrile and the monomer unit of methacrylonitrile) may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 92% by mass or more, 95% by mass or more, 96% by mass or more, 98% by mass or more, 99% by mass or more, 99.5% by mass or more, or substantially 100% by mass, based on the whole of the aromatic vinyl polymer, from the viewpoint of easily obtaining excellent volume feeling, comb-through property and spinnability.

[0033] The content of the aromatic vinyl polymer is more than 0% by mass and less than 100% by mass based on the total mass of the fiber for artificial hair or the total amount of the vinyl chloride polymer and the aromatic vinyl polymer, and may be within the following ranges. From the viewpoint of easily obtaining an excellent volume feeling, the content of the aromatic vinyl polymer may be 2% by mass or more, 4% by mass or more, 5% by mass or more, more than 5% by mass, 10% by mass or more, 15% by mass or more, 17% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, or 35% by mass or more. From the viewpoint of easily obtaining excellent combability and spinnability, the content of the aromatic vinyl polymer may be 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 17% by mass or less, 15% by mass or less, 10% by mass or less, 5% by mass or less, less than 5% by mass, or 4% by mass or less. From these viewpoints, the content of the aromatic vinyl polymer may be 2 to 60% by mass, 4 to 50% by mass, 4 to 40% by mass, 4 to 35% by mass, 4 to 30% by mass, 5 to 40% by mass, 10 to 35% by mass, 20 to 35% by mass, or 30 to 35% by mass.

[0034] The combination of the content of the vinyl chloride polymer and the content of the aromatic vinyl polymer is arbitrary, and each of the content of the vinyl chloride polymer and the content of the aromatic vinyl polymer may be within the above-mentioned respective ranges. For example, the fiber for artificial hair according to the present embodiment may be in a mode where the content of the vinyl chloride polymer is 40 to 98% by mass and the content of the aromatic vinyl polymer is 2 to 60% by mass based on the total mass of the fiber for artificial hair or the total amount of the vinyl chloride polymer and the aromatic vinyl polymer, may be in a mode where the content of the vinyl chloride polymer is 60 to 95% by mass and the content of the aromatic vinyl polymer is 5 to 40% by mass, or may be in a mode where the content of the vinyl chloride polymer is 68 to 90% by mass and the content of the aromatic vinyl polymer is 10 to 32% by mass.

[0035] The total amount of the vinyl chloride polymer and the aromatic vinyl polymer may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 92% by mass or more, 95% by mass or more, 96% by mass or more, 98% by mass or more, 99% by mass or more, 99.5% by mass or more, or substantially 100% by mass, based on the total mass of the fibers for artificial hair.

[0036] The fibers for artificial hair according to this embodiment may contain components other than the vinyl chloride polymer and the aromatic vinyl polymer. Examples of such components include polymers other than the vinyl chloride polymer and the aromatic vinyl polymer (polyolefins such as polypropylene; polyethylene terephthalate; polymers of (meth)acrylic acid compounds such as (meth)acrylic acid and (meth)acrylic acid esters), antistatic agents, heat stabilizers, lubricants, processing aids, plasticizers, reinforcing agents, ultraviolet absorbers, antioxidants, fillers, flame retardants, pigments, initial coloring improvers, conductivity imparting agents, fragrances, and the like. The fibers for artificial hair according to this embodiment do not necessarily contain at least one of such components, and do not necessarily contain at least one selected from the group consisting of polymers of polyolefins (such as polypropylene), polyethylene terephthalate, and (meth)acrylic acid compounds ((meth)acrylic acid, (meth)acrylic acid esters, etc.).

[0037] Examples of the antistatic agent include cationic, anionic, amphoteric, and other antistatic agents. The content (blending amount) of the antistatic agent may be 0.01 to 1 part by mass with respect to 100 parts by mass in total of the vinyl chloride polymer and the aromatic vinyl polymer, or 100 parts by mass of the fibers for artificial hair (fibrous resin composition).

[0038] The heat stabilizer can be used to adjust thermal decomposition during molding, long-term properties, the color tone of the filaments, and the like. Examples of the heat stabilizer include Ca-Zn based heat stabilizers, hydrotalcite based heat stabilizers, tin based heat stabilizers, epoxy based heat stabilizers, β-diketone based heat stabilizers, and the like. The content (blending amount) of the heat stabilizer may be 0.1 to 5.0 parts by mass with respect to 100 parts by mass in total of the vinyl chloride polymer and the aromatic vinyl polymer, or 100 parts by mass of the fibers for artificial hair (fibrous resin composition).

[0039] Examples of the Ca-Zn based heat stabilizer include zinc stearate, calcium stearate, zinc 12-hydroxystearate, calcium 12-hydroxystearate, etc. Examples of the hydrotalcite based heat stabilizer include hydrotalcite compounds, etc. Examples of the hydrotalcite compound include a composite salt compound composed of magnesium and / or an alkali metal and aluminum; a composite salt compound composed of zinc, magnesium and aluminum; a compound obtained by dehydrating crystal water, etc. Examples of the tin based heat stabilizer include mercapto tin based heat stabilizers such as dimethyltin mercapto, dimethyltin mercaptide, dibutyltin mercapto, dioctyltin mercapto, dioctyltin mercapto polymer, dioctyltin mercaptoacetate, etc.; maleate tin based heat stabilizers such as dimethyltin maleate, dibutyltin maleate, dioctyltin maleate, dioctyltin maleate polymer, etc.; laurate tin based heat stabilizers such as dimethyltin laurate, dibutyltin laurate, dioctyltin laurate, etc. Examples of the epoxy based heat stabilizer include epoxidized soybean oil, epoxidized linseed oil, etc. Examples of the β-diketone based heat stabilizer include stearoylbenzoylmethane (SBM), dibenzoylmethane (DBM), etc.

[0040] The lubricant can be used to reduce the friction between the metal surface of the processing machine and between the resins, improve the fluidity and adjust the processability. Examples of the lubricant include metal soap based lubricants, higher fatty acid based lubricants, ester based lubricants, higher alcohol based lubricants, hydrocarbon based lubricants, etc. The content (blending amount) of the lubricant may be 0.2 to 5.0 parts by mass with respect to 100 parts by mass in total of the vinyl chloride polymer and the aromatic vinyl polymer, or 100 parts by mass of the fiber for artificial hair (fibrous resin composition).

[0041] Examples of metal soap lubricants include metal soaps (e.g., stearates, laurates, palmitates, oleates of Na, Mg, Al, Ca, Ba, etc.). Examples of higher fatty acid lubricants include saturated fatty acids such as stearic acid, palmitic acid, myristic acid, lauric acid, capric acid; unsaturated fatty acids such as oleic acid; and mixtures thereof. Examples of ester lubricants include pentaerythritol lubricants, montanic acid wax lubricants, lubricants composed of alcohols and fatty acids, etc. Examples of pentaerythritol lubricants include monoester, diester, triester, or tetraester of pentaerythritol or dipentaerythritol and higher fatty acids; and mixtures thereof. Examples of montanic acid wax lubricants include esters of montanic acid and higher alcohols (such as stearyl alcohol, palmityl alcohol, myristyl alcohol, lauryl alcohol, oleyl alcohol, etc.). Examples of higher alcohol lubricants include stearyl alcohol, palmityl alcohol, myristyl alcohol, lauryl alcohol, oleyl alcohol, etc. Examples of hydrocarbon lubricants include polyethylene wax, polypropylene wax, etc.

[0042] In the fiber for artificial hair according to this embodiment, the content of the vinyl chloride-based acrylic graft copolymer may be 1 part by mass or less, less than 1 part by mass, 0.1 part by mass or less, 0.01 part by mass or less, or substantially 0 part by mass with respect to a total of 100 parts by mass of the vinyl chloride polymer and the vinyl polymer (e.g., aromatic vinyl polymer).

[0043] The method for producing the fiber for artificial hair according to this embodiment includes a heating step of obtaining the fiber for artificial hair by heat-treating a base fiber containing a vinyl chloride polymer and an aromatic vinyl polymer. The base fiber may be a fiber obtained in the stretching step described later. In the heating step, for example, using a heat treatment machine, in an air atmosphere, the base fiber may be heat-treated until the total fiber length shrinks to 0.5 to 0.9 times that before the treatment.

[0044] The glass transition temperature (Tg) of the base fiber may be in the following range. From the viewpoint of easily obtaining excellent comb-through property, the glass transition temperature may be 80°C or higher, 85°C or higher, 90°C or higher, 94°C or higher, 95°C or higher, 100°C or higher, 104°C or higher, 105°C or higher, 108°C or higher, 109°C or higher, 110°C or higher, 115°C or higher, 116°C or higher, 120°C or higher, or 124°C or higher. From the viewpoint of easily obtaining excellent volume feeling, the glass transition temperature may be 150°C or lower, 140°C or lower, 130°C or lower, 125°C or lower, 124°C or lower, 120°C or lower, 116°C or lower, 115°C or lower, 110°C or lower, 109°C or lower, 108°C or lower, 105°C or lower, 104°C or lower, or 100°C or lower. The glass transition temperature may be 95°C or lower, or 94°C or lower. From these viewpoints, the glass transition temperature may be 80 to 150°C, 94 to 124°C, or 100 to 115°C. The glass transition temperature can be measured by the method described in the examples below.

[0045] The heating temperature in the heating step may be less than 120°C, 115°C or lower, 110°C or lower, or 105°C or lower. The heating temperature in the heating step may be 80°C or higher, 90°C or higher, 100°C or higher, 105°C or higher, or 110°C or higher. From these viewpoints, the heating temperature in the heating step may be 80°C or higher and less than 120°C, 90 to 115°C, or 100 to 110°C.

[0046] In the method for manufacturing fibers for artificial hair according to this embodiment, fibers for artificial hair with a large heat shrinkage rate at 100°C can be easily obtained at a heating temperature of less than 120°C (for example, 110°C or lower). For example, when the glass transition temperature of the base fiber is low (for example, the glass transition temperature is less than 120°C) and the temperature difference between the glass transition temperature and 100°C, the temperature at which the heat shrinkage rate is measured, is small, fibers for artificial hair with a large heat shrinkage rate can be easily obtained when the heating temperature is less than 120°C. Also, when the glass transition temperature of the base fiber is high (for example, the glass transition temperature is 120°C or higher), even when the temperature difference between the glass transition temperature and 100°C, the temperature at which the heat shrinkage rate is measured, is large, fibers for artificial hair with a large heat shrinkage rate can be easily obtained when the heating temperature is less than 120°C.

[0047] The method for manufacturing fibers for artificial hair according to this embodiment may include a melt-kneading step of melt-kneading a vinyl chloride polymer and an aromatic vinyl polymer. In the melt-kneading step, for example, after stirring and mixing the vinyl chloride polymer and the aromatic vinyl polymer to obtain a powder compound, the powder compound is melt-kneaded to obtain a pellet compound. When stirring and mixing the vinyl chloride polymer and the aromatic vinyl polymer, an antistatic agent, a heat stabilizer, a lubricant, etc. may be appropriately mixed. For the stirring and mixing to obtain the powder compound, a Henschel mixer, a super mixer, a ribbon blender, etc. can be used. For the melt-kneading to obtain the pellet compound, a single-screw extruder, a twin-screw extruder with opposite directions, a conical twin-screw extruder, a twin-screw extruder with the same direction, a co-kneader, a planetary gear extruder, a roll kneader, etc. can be used.

[0048] The method for manufacturing fibers for artificial hair according to this embodiment may include a melt-spinning step of melt-spinning a resin composition (the pellet compound obtained in the melt-kneading step) containing a vinyl chloride polymer and an aromatic vinyl polymer after the melt-kneading step. In the melt-spinning step, for example, using a metal nozzle having a plurality of nozzle holes, the resin composition is extruded and melt-spun under the conditions of a cylinder temperature of 140 to 190°C and a nozzle temperature of 180 ± 15°C. For the extrusion, a single-screw extruder, a twin-screw extruder with opposite directions, a conical twin-screw extruder, etc. can be used, and a single-screw extruder with a diameter of 30 to 85 mmφ or a conical extruder with a diameter of 30 to 50 mmφ can be used.

[0049] The method for manufacturing fibers for artificial hair according to this embodiment may include a winding step of winding the fibers obtained in the melt-spinning step after the melt-spinning step. In the winding step, the fibers obtained in the melt-spinning step may be introduced into a heating cylinder (heating cylinder temperature: about 250°C), instantaneously heat-treated, and then wound by a take-up machine. When winding, the take-up speed may be adjusted so that the denier per filament of the fiber is 150 to 206 decitex.

[0050] The manufacturing method of the fiber for artificial hair according to this embodiment may include a stretching step of obtaining a base fiber (a base fiber heat-treated in the heating step) by stretching a fiber (an unstretched fiber) after the winding step. In the stretching step, for example, the unstretched fiber may be stretched 2 to 4 times with a stretching machine (in an air atmosphere at 90 to 120 °C).

[0051] The fiber bundle for artificial hair according to this embodiment includes the fiber for artificial hair according to this embodiment. The fiber bundle for artificial hair according to this embodiment may be an aspect in which a plurality of the fibers for artificial hair according to this embodiment are provided. One aspect of the fiber bundle for artificial hair according to this embodiment may be a fiber bundle composed of the fibers for artificial hair according to this embodiment. Another aspect of the fiber bundle for artificial hair according to this embodiment may further include a fiber different from the fiber for artificial hair according to this embodiment (a fiber for artificial hair; a fiber not corresponding to the fiber for artificial hair according to this embodiment), that is, it may include the fiber for artificial hair according to this embodiment and a fiber different from the fiber for artificial hair according to this embodiment.

[0052] By using in combination the fiber for artificial hair according to this embodiment and a fiber different from the fiber for artificial hair according to this embodiment, it is possible to obtain other desired properties while obtaining an excellent sense of volume. The constituent material of the fiber different from the fiber for artificial hair according to this embodiment may be a fiber that does not contain a vinyl chloride polymer and an aromatic vinyl polymer, a fiber that contains one of a vinyl chloride polymer and an aromatic vinyl polymer, or a fiber having a heat shrinkage rate of less than 7% at 100 °C. Examples of the constituent material of the fiber different from the fiber for artificial hair according to this embodiment include polyolefins such as polypropylene; polyethylene terephthalate; polymers of (meth) acrylic acid compounds such as (meth) acrylic acid and (meth) acrylic acid esters.

[0053] The fiber for artificial hair and the fiber bundle for artificial hair according to this embodiment can be used in the hair decoration product according to this embodiment. The hair decoration product according to this embodiment includes the fiber for artificial hair according to this embodiment and may include the fiber bundle for artificial hair according to this embodiment. Examples of the hair decoration product include wigs and the like. The fiber for artificial hair and the fiber bundle for artificial hair in the hair decoration product according to this embodiment may be in any state before and after the gear processing treatment for shrinking the fiber for artificial hair. The artificial hair according to this embodiment can be obtained by subjecting the fiber for artificial hair according to this embodiment to gear processing treatment.

Example

[0054] Hereinafter, examples and comparative examples will be shown to explain the specific embodiments of the present invention in more detail. However, the present invention is not limited only to this example.

[0055] <Production of Fiber for Artificial Hair> (Example 1) 70 parts by mass of a vinyl chloride polymer (vinyl chloride-based resin, homopolymer of vinyl chloride, manufactured by Taiyo Vinyl Co., Ltd., trade name: TH-1000), 30 parts by mass of an aromatic vinyl polymer (aromatic vinyl-based copolymer resin, manufactured by Denka Co., Ltd., trade name: GR-AT-6S) containing 68% by mass of styrene monomer units and 32% by mass of acrylonitrile monomer units, 0.5 part by mass of an antistatic agent (manufactured by NOF Corporation, trade name: New Elegant ASK), 3 parts by mass of a hydrotalcite-based composite salt compound (manufactured by Nissan Chemical Industries, Ltd., trade name: CP-410A), 0.5 part by mass of epoxidized soybean oil (manufactured by Asahi Denka Co., Ltd., trade name: O-130P), and 0.8 part by mass of an ester-based lubricant (manufactured by Riken Vitamin Co., Ltd., trade name: EW-100) were prepared. Using the resin composition, pellets were produced by performing compounding with an extruder having a diameter (caliber) of 40 mm at a cylinder temperature of 130 to 170°C. Next, the nozzle cross-sectional area was 0.06 mm 2, Using a nozzle with a round shape and 120 holes, at a cylinder temperature of 140 - 190 °C and a nozzle temperature of 180 °C, the above pellets were melt-spun with an extrusion amount of 10 kg / hour using an extruder with a diameter of 30 mm. Then, a fiber A (undeformed fiber) of 150 dtex was obtained by heat-treating for 1.0 second with a heating cylinder (250 °C) provided at a position 4.5 m directly below the nozzle.

[0056] As the glass transition temperature (Tg) of the above fiber A, the peak top temperature of the loss tangent (tanδ) in the dynamic viscoelasticity measurement was measured. Specifically, using a dynamic viscoelasticity measurement device (manufactured by SII NanoTechnology Inc., DMS6100), at a heating rate of 4 °C / min, a frequency of 1 Hz, and a chuck distance of 3 mm, the loss tangent (tanδ) of a fiber bundle of 40 fiber As in the range of 25 - 170 °C was measured, and the peak top temperature was measured. The glass transition temperature of the fiber A in Example 1 was 124 °C.

[0057] Next, fiber B was obtained by stretching fiber A three times in an air atmosphere at 100 °C.

[0058] Next, in an air atmosphere, at a heating temperature (annealing temperature) of 110 °C, fiber B was heat-treated until the total fiber length shrank to 0.75 times that before the treatment, thereby obtaining a fiber for artificial hair of 60 dtex.

[0059] (Examples 2 - 11 and Comparative Examples 1 - 3) Fibers for artificial hair of 60 dtex were obtained in the same manner as in Example 1, except that the content of the vinyl chloride polymer, the content of the aromatic vinyl polymer, the ratio of the monomer units in the aromatic vinyl polymer, and the heating temperature (annealing temperature) of the heat treatment after the stretching treatment were changed to the values in Tables 1 and 2. As the aromatic vinyl polymer different from that in Example 1, the following aromatic vinyl polymers were used. The measurement results of the glass transition temperature of fiber A are shown in Tables 1 and 2.

[0060] An aromatic vinyl polymer containing 70% by mass of styrene monomer units and 30% by mass of acrylonitrile monomer units (manufactured by Denka Co., Ltd., trade name: GR-AT-R) An aromatic vinyl polymer containing 75% by mass of styrene monomer units and 25% by mass of acrylonitrile monomer units (manufactured by Denka Co., Ltd., trade name: AS700) An aromatic vinyl polymer containing 80% by mass of styrene monomer units and 20% by mass of acrylonitrile monomer units (manufactured by Denka Co., Ltd., trade name: AS-3) An aromatic vinyl polymer containing 82% by mass of styrene monomer units and 18% by mass of acrylonitrile monomer units (manufactured by Denka Co., Ltd., trade name: AS-C800) An aromatic vinyl polymer containing 86% by mass of styrene monomer units and 14% by mass of acrylonitrile monomer units (self-prepared product) An aromatic vinyl polymer containing 90% by mass of styrene monomer units and 10% by mass of acrylonitrile monomer units (self-prepared product)

[0061] <Heat shrinkage rate of fiber for artificial hair> First, the above-mentioned fiber for artificial hair was cut into pieces with a length of 100 mm to obtain fiber pieces. Next, the fiber pieces were heated in an oven set at 100 °C for 10 minutes, and then the length of the fiber pieces was measured. The heat shrinkage rate was calculated according to the following formula. The results are shown in Table 1 and Table 2. Heat shrinkage rate (%) = {[(Length before heating) - (Length after heating)] / (Length before heating)} × 100

[0062] <Evaluation> For the above-mentioned fiber for artificial hair, the spinnability, volume feeling, and combability (comb-through resistance) were evaluated according to the following evaluation methods and criteria. The results are shown in Table 1 and Table 2. In the examples, it was confirmed that good results were obtained in all evaluation items.

[0063] (Spinnability) Regarding spinnability, during the production of the above-mentioned fiber for artificial hair, the occurrence of thread breaks per hour during melt spinning to form fiber A (unoriented fiber) was visually observed. The spinnability was evaluated according to the following criteria. A: Thread break occurred once B: Thread breaks occurred 2 - 3 times C: Thread breaks occurred 4 times or more

[0064] (Volume feeling) The volume feeling was evaluated by the following procedure. First, after obtaining evaluation fibers by subjecting the fiber bundle of the above-mentioned fiber for artificial hair (number of fibers: 12,000, length: 10 m, mass: 800 g) to gear processing (processing in the length direction of the fiber, depth of the groove of the gear waveform: 2.5 mm, gear pitch: 2.5 mm, surface temperature: 90 °C, processing speed: 1.0 m / min), fiber pieces were obtained by cutting the evaluation fibers to a length of 100 mm. Next, the container was filled with the fiber pieces until it was full with a 56 cc container (100 mm × 14 mm × 40 mm). After taking out the filled fiber pieces, the mass of the fiber pieces was measured. Then, the specific volume was calculated from the formula "volume of the container (cc) / mass of the fiber piece (g) = specific volume (cc / g)". The value of the specific volume was calculated by rounding off the second decimal place. When the specific volume exceeded 7.0 cc / g, it was judged to be good.

[0065] (Comb-through property) The comb-through property was evaluated by the following procedure. First, a fiber bundle of evaluation fibers was obtained by subjecting the fiber bundle of the above-mentioned fiber for artificial hair (number of fibers: 12,000, length: 10 m, mass: 800 g) to gear processing (processing in the length direction of the fiber, depth of the groove of the gear waveform: 2.5 mm, gear pitch: 2.5 mm, surface temperature: 90 °C, processing speed: 1.0 m / min). After adjusting this fiber bundle to a length of 30 cm and a mass of 20 g, the resistance force [unit: gf] when combing through at a moving speed of 10 mm / sec and a moving distance of 100 mm was measured with a static and dynamic friction measuring machine (manufactured by TRINITY-LAB, product name "TL201Tt"). It was judged that the smaller the resistance force, the better the comb-through property.

[0066]

Table 1

[0067]

Table 2

Claims

1. containing a vinyl chloride polymer and an aromatic vinyl polymer, the content of the vinyl chloride polymer is more than 0% by mass and 75% by mass or less based on the total amount of the vinyl chloride polymer and the aromatic vinyl polymer, the aromatic vinyl polymer has a styrene-based compound and (meth)acrylonitrile as monomer units, the total amount of the monomer units of the styrene-based compound and the monomer units of (meth)acrylonitrile is 90% by mass or more based on the whole aromatic vinyl polymer, a fiber for artificial hair having a heat shrinkage rate at 100 °C of 7% or more.

2. the fiber for artificial hair according to claim 1, wherein the heat shrinkage rate is 7 to 25%.

3. The fiber for artificial hair according to claim 1, wherein the content of the vinyl chloride polymer is 60 to 75% by mass and the content of the aromatic vinyl polymer is 25 to 40% by mass based on the total amount of the vinyl chloride polymer and the aromatic vinyl polymer.

4. the fiber for artificial hair according to claim 1, wherein the styrene-based compound contains styrene.

5. the fiber for artificial hair according to claim 1, wherein the proportion of the monomer units of the styrene-based compound is 74 to 88% by mass and the proportion of the monomer units of (meth)acrylonitrile is 12 to 26% by mass based on the whole aromatic vinyl polymer.

6. a fiber bundle for artificial hair comprising the fiber for artificial hair according to any one of claims 1 to 5.

7. the fiber bundle for artificial hair according to claim 6, further comprising a fiber different from the fiber for artificial hair.

8. a hair decoration product comprising the fiber bundle for artificial hair according to claim 6.

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