Artificial hair fibers and method for manufacturing artificial hair fibers

Abstract

The objective of this invention is to provide artificial hair fibers that can reduce environmental impact. [Solution] One aspect of the present invention is an artificial hair fiber having a base fiber containing polyvinyl chloride resin, wherein the polyvinyl chloride resin contains plant-derived polyvinyl chloride resin. Another aspect of the present invention is a method for producing an artificial hair fiber having a base fiber containing polyvinyl chloride resin, wherein at least a portion of the polyvinyl chloride resin is allocated a sustainable ratio using a mass balance method. Furthermore, the method includes an internal lubricant addition step in which an internal lubricant is added to the polyvinyl chloride resin to form a resin composition, and the maximum torque of the resin composition when melt-kneaded at a resin temperature of 170°C using a plastograph is 25 to 45 N·m.

Description

Technical Field

[0001] The present invention relates to fibers for artificial hair and a method for producing the same.

Background Art

[0002] )] In hair decoration products such as wigs, hairpieces, false eyelashes, hair bands, and doll hair, the importance of artificial hair as a substitute for human hair has been increasing. As materials constituting fibers for artificial hair, there are acrylic resins, vinyl chloride resins, or polyester resins, and fibers for artificial hair made of these resins are commercially available.

[0003] Patent Document 1 discloses a technique of treating base fibers with a predetermined fiber treatment agent for the purpose of providing a fiber treatment agent that gives good luster and smoothness to fibers, does not make the fibers squeak, and has excellent volume even when the fiber is a vinyl chloride resin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, the environmental burden caused by products using fossil fuel-derived polyvinyl chloride resins has become a problem. The present invention has been made in view of such circumstances, and a first object thereof is to provide fibers for artificial hair that can reduce the environmental burden.

[0006] Furthermore, the inventors' investigations revealed that some artificial hair fibers using polyvinyl chloride resin, which can reduce environmental impact, have inferior physical properties compared to those using conventional polyvinyl chloride resin derived from fossil fuels. Therefore, the second objective of the present invention is to provide a manufacturing method that allows for the production of artificial hair fibers having properties (color development, tensile properties, bending rigidity, and heat resistance) equivalent to those of conventional artificial hair fibers using only polyvinyl chloride resin derived from fossil fuels, even when including polyvinyl chloride resin that can reduce environmental impact. [Means for solving the problem]

[0007] Through diligent research, the inventors discovered that the first problem of this invention can be solved by using a specific type of polyvinyl chloride resin. Furthermore, they discovered that the second problem of this invention can be solved by adjusting the composition of the resin composition to satisfy specific parameters when using a polyvinyl chloride resin that can reduce environmental impact, thus completing the present invention.

[0008] According to the present invention, the following is provided: [1] A fiber for artificial hair having a base fiber containing polyvinyl chloride resin, The above polyvinyl chloride resin includes plant-derived polyvinyl chloride resin, and is used as a fiber for artificial hair. [2] The above base fiber further contains an internal lubricant, The artificial hair fiber according to [1], wherein the content of the plant-derived polyvinyl chloride resin in 100% by mass of the polyvinyl chloride resin is a% by mass, and the content of the internal lubricant in 100 parts by mass of the polyvinyl chloride resin is within the range of the following formula 1.

number

number

[0009] According to the present invention, it is possible to provide artificial hair fibers that can reduce environmental impact. Furthermore, according to the present invention, even when the present invention contains polyvinyl chloride resin that can reduce environmental impact, it is possible to provide a manufacturing method that can obtain artificial hair fibers having the same properties (color development, tensile properties, bending rigidity, and heat resistance) as conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin as the polyvinyl chloride resin. [Modes for carrying out the invention]

[0010] The present invention will now be described in detail. The present invention is not limited to these descriptions. The features of the embodiments shown below can be combined with each other. Furthermore, each feature constitutes an invention independently. In addition, any element of the embodiments below that is not defined in the claims is optional and can be omitted. In this specification, any number of zeros may be added to the end of numerical values. For example, one zero may be added after "1.4" to make it "1.40".

[0011] <Explanation of Terms> In this specification, for example, the notation "X~Y" means that it is greater than or equal to X and less than or equal to Y.

[0012] 1. Fibers for artificial hair The first embodiment of the present invention is a fiber for artificial hair. The fiber for artificial hair according to this embodiment has a base fiber. The base fiber according to this embodiment may optionally have a surface treatment agent attached to at least a portion of the surface of the base fiber.

[0013] 1.1 Base Fibers 1.1.1 Polyvinyl chloride resin The base fiber according to this embodiment contains polyvinyl chloride resin. The base fiber according to this embodiment may be produced by spinning polyvinyl chloride resin, or by spinning a resin composition containing polyvinyl chloride resin and other components (e.g., an internal lubricant). The polyvinyl chloride resin according to this embodiment contains a polyvinyl chloride resin that can reduce environmental impact, and in one embodiment, it contains plant-derived polyvinyl chloride resin. In addition, the polyvinyl chloride resin according to this embodiment may contain other polyvinyl chloride resins (specifically, fossil fuel-derived polyvinyl chloride resins) in addition to plant-derived polyvinyl chloride resins.

[0014] In this specification, "plant-derived polyvinyl chloride resin" means polyvinyl chloride resin made using plant-derived raw materials, and includes polyvinyl chloride resin obtained from raw materials mixed with plant-derived raw materials and other raw materials (for example, raw materials derived from fossil fuels). In this embodiment, the plant-derived raw materials are biomass (non-fossil fuel) raw materials, and examples include cellulosic crops (pulp, kenaf, wheat straw, rice straw, waste paper, papermaking residue, etc.), wood, charcoal, compost, natural rubber, cotton, sugarcane, okara, oils and fats (rapeseed oil, cottonseed oil, soybean oil, coconut oil, castor oil, etc.), carbohydrate crops (corn, potatoes, wheat, rice, rice husks, rice bran, old rice, cassava, sago palm, etc.), bagasse, buckwheat, soybeans, essential oils (pine root oil, orange oil, eucalyptus oil, etc.), pulp black liquor, and vegetable oil residue. In this embodiment, the plant-derived polyvinyl chloride resin is preferably derived from pulp. Herein, in this specification, "plant-derived raw materials" is not limited to unused plant-derived raw materials, but also includes plant-derived waste and residues.

[0015] Whether polyvinyl chloride resin is plant-derived polyvinyl chloride resin can be determined, for example, by elemental analysis. 14 This can be determined by whether or not carbon (C) is detected. Fossil fuels, such as petroleum, coal, natural gas, and shale gas, are made from the remains of plants and animals that have been decomposed under pressure over hundreds of millions of years by soil and geothermal heat, liquefying and then turning into gas. 14 A considerable amount of time has passed since the half-life of the 1C isotope, which is 5700 years. Therefore, in elemental analysis, fossil fuel-derived polyvinyl chloride resin is 14 C is not detected (in other words, "fossil fuel-derived polyvinyl chloride resin" as used herein refers to polyvinyl chloride resin that does not use plant-derived raw materials, and in elemental analysis, 14 (C means not detected). On the other hand, carbon in biomass-derived raw materials is 14 Because it contains a certain amount of C isotope, plant-derived polyvinyl chloride resin is used in elemental analysis. 14 C is detected.

[0016] The K value of the polyvinyl chloride resin according to this embodiment is preferably 60 to 80, and more preferably 65 to 75. The K value of the polyvinyl chloride resin may be, for example, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 or 80, or may be within the range between any two of the values exemplified herein. When a plurality of polyvinyl chloride resins are contained in the base material fiber, among the total 100% by mass of the polyvinyl chloride resins, the content of the polyvinyl chloride resin having a K value within the above range is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. When a plurality of polyvinyl chloride resins are contained in the base material fiber, it is particularly preferable that the K values of all the polyvinyl chloride resins are within the above range. The K value and content of each polyvinyl chloride resin in the base material fiber can be estimated from the molecular weight distribution measured by the GPC / SEC method (gel permeation chromatography or size exclusion chromatography). When the K value of the polyvinyl chloride resin is at least the lower limit value, sufficient torque is applied during kneading, so sufficient kneading and gelation are performed, and as a result, the tensile strength and bending rigidity of the fiber for artificial hair are further improved. When the K value of the polyvinyl chloride resin is at most the upper limit value, the gelation time during kneading is appropriate, so discoloration of the resin hardly occurs, and as a result, the fiber for artificial hair is more excellent in color development.

[0017] The total apparent specific gravity of the polyvinyl chloride resin according to this embodiment is preferably 0.40 to 0.70 kg / dm 3 and more preferably 0.50 to 0.65 kg / dm 3 and even more preferably 0.55 to 0.60 kg / dm 3 Note that the "total apparent specific gravity of the polyvinyl chloride resin" in this specification can be calculated as follows when a plurality of polyvinyl chloride resins are contained in the base material fiber. For example, when among 100% by mass of the polyvinyl chloride resin, the polyvinyl chloride resin having an apparent specific gravity S is s% by mass and the polyvinyl chloride resin having an apparent specific gravity T is t% by mass (s + t = 100), it can be calculated by the following formula. S × (s / 100) + T × (t / 100) Furthermore, when multiple polyvinyl chloride resins are contained in the base fiber, it is preferable that the content of polyvinyl chloride resins with apparent specific gravity within the above range is 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, out of the total 100% by mass of polyvinyl chloride resins. When multiple polyvinyl chloride resins are contained in the base fiber, it is particularly preferable that the apparent specific gravity of all polyvinyl chloride resins is within the above range. If the (total) apparent specific gravity of the polyvinyl chloride resins is above the lower limit, the gelation time during kneading becomes appropriate, making discoloration of the resin less likely, and consequently the artificial hair fibers have better color development. If the (total) apparent specific gravity of the polyvinyl chloride resins is below the upper limit, sufficient torque is applied during kneading, resulting in sufficient kneading and gelation, and consequently the tensile strength and bending rigidity of the artificial hair fibers are further improved.

[0018] 1.1.2 Internal lubricant The base fiber according to this embodiment preferably further contains an internal lubricant. In this specification, "internal lubricant" means a substance that reduces friction between resins when polyvinyl chloride resin is melted. The inclusion of an internal lubricant improves the thermal stability of the resin composition. Examples of internal lubricants according to this embodiment include metal soap-based lubricants, fatty acid ester-based lubricants, fatty acid alcohol-based lubricants, and ester-based lubricants. Examples of metal soap-based lubricants include calcium stearate, zinc stearate, magnesium stearate, aluminum stearate, and lead stearate. Examples of fatty acid ester-based lubricants include butyl stearate, butyl laurate, and stearyl stearate. Examples of fatty acid alcohol-based lubricants include stearyl alcohol, lauryl alcohol, and palmityl alcohol. Examples of ester-based lubricants include glycerin monostearate and butyl stearate. These internal lubricants may be used individually or in combination of two or more types.

[0019] The internal lubricant according to this embodiment preferably contains a metal soap-based lubricant, and it is particularly preferable to use calcium stearate and zinc stearate in combination. Since calcium stearate and zinc stearate have different decomposition temperatures, using them together further enhances the effect of the internal lubricant. When calcium stearate and zinc stearate are used together, the content ratio (parts by mass) of calcium stearate and zinc stearate is preferably 1:10 to 10:1, more preferably 1:5 to 5:1, and even more preferably 1:3 to 3:1. When the content ratio (parts by mass) of calcium stearate and zinc stearate is within this range, the effect of the internal lubricant is further enhanced.

[0020] The content of the internal lubricant according to this embodiment can be determined according to the content of plant-derived polyvinyl chloride resin in the polyvinyl chloride resin. Specifically, when the content of plant-derived polyvinyl chloride resin in 100% by mass of polyvinyl chloride resin is a% by mass, the content of the internal lubricant in parts x by mass per 100 parts by mass of polyvinyl chloride resin is preferably within the range of the following formula 1.

number

[0021] Furthermore, the content of plant-derived polyvinyl chloride resin and fossil fuel-derived polyvinyl chloride resin in the polyvinyl chloride resin of artificial hair fibers can be estimated by measuring the molecular weight distribution if the K values ​​of the plant-derived and fossil fuel-derived polyvinyl chloride resins differ. The molecular weight distribution of artificial hair fibers can be measured by the GPC / SEC method (gel permeation chromatography or size exclusion chromatography).

[0022] 1.1.3 Other ingredients The base fiber according to this embodiment may also contain other components as needed. Other components include resin components other than polyvinyl chloride resin (e.g., AS resin), stabilizers, antistatic agents, heat stabilizers, lubricants, colorants, processing aids, plasticizers, reinforcing agents, ultraviolet absorbers, antioxidants, fillers, flame retardants, pigments, initial color improvers, conductivity imparters, and fragrances. The resin composition according to this embodiment may contain, for example, 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less of other components per 100 parts by mass of polyvinyl chloride resin.

[0023] 1.2 Surface treatment agents The artificial hair fiber according to this embodiment may comprise a base fiber and a surface treatment agent attached to at least a portion of the surface of the base fiber. The surface treatment agent according to this embodiment is preferably one or more selected from the group consisting of oils, nonionic surfactants, and cationic surfactants.

[0024] The amount of surface treatment agent applied to the artificial hair fibers according to this embodiment is preferably 0.05 to 1.0 parts by mass, and more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of base fiber. The amount of surface treatment agent applied may be, for example, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 parts by mass per 100 parts by mass of base fiber, and may be within the range of any two of the values ​​exemplified here. If the amount of surface treatment agent applied to the artificial hair fibers is above the lower limit, the artificial hair fiber bundle will have excellent combability and be given softness. If the amount of surface treatment agent applied to the artificial hair fibers is below the upper limit, the stickiness of the artificial hair fiber bundle will be reduced.

[0025] 2. Method for manufacturing fibers for artificial hair A second embodiment of the present invention is a method for producing artificial hair fibers having a base fiber containing polyvinyl chloride resin. The polyvinyl chloride resin in this embodiment may be the plant-derived polyvinyl chloride resin described above, or fossil fuel-derived polyvinyl chloride, or a combination of both. Furthermore, in this embodiment, at least a portion of the polyvinyl chloride resin is assigned a sustainable ratio using a mass balance method. The mass balance method is a method in which, when raw materials with different properties are mixed, the properties of a certain raw material are arbitrarily assigned to a portion of the product to be produced according to the amount of raw material with that property input. In this embodiment, at least a portion of the polyvinyl chloride resin is produced by mixing sustainable raw materials (specifically, the plant-derived raw materials described above) and fossil fuel-derived raw materials using conventional equipment and manufacturing methods, and has an arbitrary sustainable ratio assigned according to the amount of sustainable raw materials input.

[0026] For example, if 40 parts by mass of plant-derived raw materials and 60 parts by mass of fossil fuel-derived raw materials are used to produce 10 polyvinyl chloride resin products with a plant-derived component content of approximately 40% by mass, the actual plant-derived component content is approximately 40% by mass in all products. However, the sustainable ratio of any four of the 10 products can be set to 100%, and the sustainable ratio of the remaining six can be set to 0%. Thus, the sustainable ratio may differ from the actual biomass component content in each product. The sustainable ratio can be arbitrarily assigned to each product within a range corresponding to the amount of sustainable raw materials used, and is not limited to 0% or 100% as described above. Preferably, the sustainable ratio of at least a portion of the polyvinyl chloride resin is 0.1 to 100%, more preferably 10 to 100%, and even more preferably 50 to 100%. The sustainable ratio of at least a portion of the polyvinyl chloride resin may be, for example, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100%, and may be within the range of any two of the values ​​exemplified herein. Furthermore, it is preferable to use a plant-derived polyvinyl chloride resin as the polyvinyl chloride resin in this embodiment, in which the sustainable ratio is assigned using a mass balance method (specifically, a sustainable ratio of 0.1% or more, preferably 10% or more, more preferably 50% or more, and even more preferably 100%). If the sustainable ratio is above the lower limit, it will contribute sufficiently to reducing the carbon footprint and reduce the environmental burden.

[0027] It is preferable that at least a portion of the polyvinyl chloride resin according to this embodiment is manufactured by a supplier that has obtained international certifications related to sustainability and carbon, such as RSB certification, ISCC EU certification, or ISCC PLUS certification. Using such polyvinyl chloride resin ensures traceability and makes the effect of reducing environmental impact more apparent.

[0028] The method for producing fibers for artificial hair according to this embodiment typically includes an internal lubricant addition step and a spinning step.

[0029] 2.1 Internal lubricant addition process 2.1.1 Addition Step The internal lubricant addition step according to this embodiment includes an addition step in which an internal lubricant is added to a polyvinyl chloride resin to form a resin composition. Here, it is preferable that the maximum torque of the resin composition after the addition of the internal lubricant is 25 to 45 N·m when melt-kneaded at a resin temperature of 170°C using a plastograph, and more preferably 30 to 40 N·m. The maximum torque when melt-kneaded at a resin temperature of 170°C using a plastograph may be, for example, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, or 45 N·m, and may be within the range of any two of the values ​​exemplified here. The plastograph can be performed using the method described in the examples. As described above, at least a portion of the polyvinyl chloride resin according to this embodiment is allocated a sustainable ratio using a mass balance method. Polyvinyl chloride resins to which a sustainable ratio is allocated using the mass balance method can actually be either plant-derived or fossil fuel-derived polyvinyl chloride resins. Even with such polyvinyl chloride resins, by ensuring that the maximum torque in the plastograph meets a predetermined range, it is possible to obtain artificial hair fibers with properties equivalent to those of conventional artificial hair fibers using only fossil fuel-derived polyvinyl chloride resin (color development, tensile properties, bending stiffness, and heat resistance, especially tensile properties, bending stiffness, and heat resistance). The value of the maximum torque in the plastograph can be adjusted by the K value of the polyvinyl chloride resin and the amount of internal lubricant added, and can be adjusted particularly by the amount of internal lubricant added.

[0030] Furthermore, regarding the resin composition after the addition of the internal lubricant, the time it takes to reach the maximum torque when melt-kneaded at a resin temperature of 170°C using a plastograph is preferably 2 to 15 minutes, more preferably 3 to 10 minutes, and even more preferably 5 to 8 minutes. The time it takes to reach the maximum torque when melt-kneaded at a resin temperature of 170°C using a plastograph may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 minutes, and may be within the range of any two of the values ​​exemplified here. By ensuring that the time it takes to reach the maximum torque in the plastograph is within a predetermined range, it is possible to obtain artificial hair fibers having properties (color development, tensile properties, bending rigidity, and heat resistance, especially color development, tensile properties, and bending rigidity) equivalent to conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin as the polyvinyl chloride resin. The value of the maximum torque in the plastograph can be adjusted by the K value of the polyvinyl chloride resin and the amount of internal lubricant added, and can be adjusted particularly by the amount of internal lubricant added.

[0031] 2.1.2 Step for determining the amount to add The internal lubricant addition step according to this embodiment preferably includes an addition amount determination step to determine the amount of internal lubricant to be added. The amount of internal lubricant to be added can be determined according to the content of plant-derived polyvinyl chloride resin in the polyvinyl chloride resin. Specifically, in the addition amount determination step, it is preferable that the amount of internal lubricant to be added x parts by mass per 100 parts by mass of polyvinyl chloride resin is within the range of the following formula 1, where a mass is the content of plant-derived polyvinyl chloride resin in 100% by mass of polyvinyl chloride resin.

number

[0032] Here, whether the polyvinyl chloride resin used is plant-derived can be determined based on data from the polyvinyl chloride resin supplier. Furthermore, whether the polyvinyl chloride resin used is plant-derived can be determined based on analytical results. Whether the polyvinyl chloride resin used is plant-derived can be determined, for example, in elemental analysis. 14 This can be determined by whether or not C is detected. In elemental analysis, plant-derived polyvinyl chloride resins are 14 C is detected. On the other hand, polyvinyl chloride resins other than plant-derived polyvinyl chloride resins (specifically, fossil fuel-derived polyvinyl chloride resins) are detected in elemental analysis. 14 C is not detected.

[0033] Furthermore, the content of plant-derived polyvinyl chloride resin and fossil fuel-derived polyvinyl chloride resin in the polyvinyl chloride resin of artificial hair fibers can be estimated by measuring the molecular weight distribution if the K values ​​of the plant-derived and fossil fuel-derived polyvinyl chloride resins differ. The molecular weight distribution of artificial hair fibers can be measured by the GPC / SEC method (gel permeation chromatography or size exclusion chromatography).

[0034] 2.2 Spinning Process In this embodiment, known spinning methods can be used for the spinning process. For example, a resin or resin composition can be extruded from a heated cylinder through a nozzle and melt-spun. Conventional extruders can be used as the extruder, such as a single-screw extruder, a twin-screw extruder with different orientations, or a conical twin-screw extruder.

[0035] The melt spinning conditions can be appropriately set depending on the type of resin and resin composition. For example, the cylinder temperature can be 150-190°C, and the nozzle temperature can be 180±15°C. The cross-sectional shape of the nozzle used in this process can be appropriately set depending on the cross-sectional shape of the artificial hair fibers to be produced.

[0036] The undrawn fibers melt-spun from the nozzle may be introduced into a heating cylinder (e.g., heating cylinder temperature 250°C) for instantaneous heat treatment, and can be wound up by a take-up machine installed directly below the nozzle (e.g., approximately 4.5 m).

[0037] 2.3 Stretching process The method for manufacturing artificial hair fibers according to this embodiment may also include a stretching step. In the stretching step according to this embodiment, the unstretched artificial hair fibers obtained in the spinning step described above can be stretched in a stretching machine to obtain stretched artificial hair fibers. For example, in the stretching step, the unstretched artificial hair fibers can be stretched 2 to 5 times in an air atmosphere at 90 to 110°C, for example.

[0038] 2.4 Heat treatment process The method for manufacturing artificial hair fibers according to this embodiment may also include a heat treatment step. In the heat treatment step according to this embodiment, the stretched artificial hair fibers can be heat-treated using a heat treatment machine. For example, in the heat treatment step, the stretched artificial hair fibers are heat-treated at 90 to 120°C in an air atmosphere to reduce their size to 0.5 to 0.99 times, thereby thermally shrinking the entire length of the fibers and obtaining heat-treated artificial hair fibers with a desired fineness. The "relaxation rate during heat treatment" is a value calculated as (rotation speed of the winding roller during annealing) / (rotation speed of the feed roller during annealing).

[0039] 2.5 Gear Machining Process The method for manufacturing artificial hair fibers according to this embodiment may also include a gear processing step. In the gear processing step according to this embodiment, crimping can be performed by passing a fiber bundle between two meshing high-temperature gears. The material of the gears used in the gear processing step, the shape of the gear's wave, the number of gears, etc., are not particularly limited. In the gear processing step, the shape of the resulting artificial hair fibers can be controlled by appropriately adjusting the groove depth of the gear's wave pattern, the surface temperature of the gear, the processing speed, the pressure conditions between the gears, etc., taking into consideration the fiber material and fineness. There are no particular limitations on these processing conditions, but as an example, the groove depth of the gear's wave pattern can be 0.2 to 6 mm, preferably 0.5 to 5 mm, the surface temperature of the gear can be 30 to 100°C, preferably 40 to 80°C, and the processing speed can be 0.5 to 10 m / min, preferably 1.0 to 8.0 m / min.

[0040] The method for manufacturing artificial hair fibers according to this embodiment may include other steps, such as a surface treatment agent application step. The surface treatment agent application step can be performed, for example, after the stretching step and before the heat treatment step. Any application method can be used for the surface treatment agent application step according to this embodiment. For example, the surface treatment agent may be applied to the artificial hair fibers by a roll transfer method, or the artificial hair fibers may be immersed in the surface treatment agent for application.

[0041] 3. Characteristics of fibers for artificial hair Even when the artificial hair fibers according to this embodiment contain polyvinyl chloride resin, which can reduce environmental impact, they have properties (color development, tensile properties, bending rigidity, and heat resistance) equivalent to conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin. The properties of the artificial hair fibers according to this embodiment will be described below. Note that for the evaluation of the following properties, heat-treated artificial hair fibers can be used.

[0042] 3.1 Color development The artificial hair fibers according to this embodiment preferably exhibit excellent color development. The color development of the artificial hair fibers is specified in CIE1976(L * ,a * ,b *) In the color space, L * ,a * ,b * The value of L of the artificial hair fiber according to this embodiment can be evaluated. * The a of the artificial hair fiber according to this embodiment is preferably 80 to 90, and more preferably 85 to 90. * The b of the artificial hair fiber according to this embodiment is preferably -0.05 to 0.05, and more preferably -0.02 to 0.02. * The value is preferably 5.0 to 6.5, and more preferably 5.0 to 5.5. Furthermore, the color development of the artificial hair fibers can also be evaluated by the color difference ΔE compared to artificial hair fibers using only fossil fuel-derived polyvinyl chloride resin as the polyvinyl chloride resin (hereinafter also referred to as "standard artificial hair fibers"; specifically, artificial hair fibers obtained by spinning, drawing, and heat-treating a resin composition of 100 parts by mass of fossil fuel-derived polyvinyl chloride resin, 0.25 parts by mass of calcium stearate, and 0.25 parts by mass of zinc stearate under the same conditions). In this embodiment, L * ,a * ,b * The value of is the value of an artificial hair fiber made using a resin composition that does not contain pigments (e.g., carbon black). The color difference ΔE in this embodiment is preferably 5.0 or less, more preferably 3.0 or less, even more preferably 1.0 or less, and particularly preferably 0. The color difference ΔE may be 5.0, 4.0, 3.0, 2.0, 1.0, or 0, and may be within the range of any two of the values ​​exemplified here. The color difference ΔE can be calculated from the following formula. In the formula, the color tone of the artificial hair fiber in this embodiment is expressed as (L * ,a * ,b * ) and the standard color tone of the artificial hair fibers is set to (L f * ,a f * ,b f * ) ΔL * =|L * -L f *| Δa * =|a * -a f * | Δb * =|b * -b f * | ΔE={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2

[0043] 3.2 Tensile properties The tensile strength of the artificial hair fiber according to this embodiment is 100 N / mm². 2 Preferably, it is 140 N / mm 2 It is more preferable that the value be greater than or equal to 160 N / mm 2 It is even more preferable that the above values ​​are met. The upper limit of the tensile strength is not particularly limited, but for example, 300 N / mm². 2 This can be done. The tensile strength of the artificial hair fiber can be, for example, the average value (for example, n=10) of the stress at fracture per unit cross-sectional area when a tensile test is performed on an artificial hair fiber (single fiber) with a chuck distance of 200 mm and a tensile speed of 200 mm / min. If the tensile strength of the artificial hair fiber is above the lower limit, even if it contains polyvinyl chloride resin which can reduce the environmental impact, it will be an artificial hair fiber that has the same tensile properties as conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin as the polyvinyl chloride resin.

[0044] The initial tensile strength of the artificial hair fibers according to this embodiment is 2500 N / mm². 2 Preferably, it is 3000 N / mm 2 It is more preferable that the value be greater than or equal to 3500 N / mm 2 It is even more preferable that the above is true. The upper limit of the initial tensile strength is not particularly limited, but for example, 5000 N / mm 2This can be done. The initial tensile strength of the artificial hair fiber can be, for example, the average value (for example, n=10) calculated from the gradient of stress with respect to the strain of the fiber in the elastic deformation region per cross-sectional area when the above-described tensile test is performed. If the initial tensile strength of the artificial hair fiber is above the lower limit, even if it contains polyvinyl chloride resin which can reduce the environmental impact, it will be an artificial hair fiber that has the same tensile properties as conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin as the polyvinyl chloride resin.

[0045] The elongation at break of the artificial hair fiber according to this embodiment is preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. The upper limit of the elongation at break is not particularly limited, but can be, for example, 95%. The elongation at break of the artificial hair fiber can be, for example, the average value of the elongation at break (for example, n=10) when the above-described tensile test is performed, with reference to the value before the start of tension. If the elongation at break of the artificial hair fiber is above the lower limit, even if it contains polyvinyl chloride resin which can reduce the environmental impact, it will be an artificial hair fiber having tensile properties equivalent to conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin as the polyvinyl chloride resin.

[0046] 3.3 Bending stiffness The bending rigidity of the artificial hair fiber according to this embodiment is 9.8 × 10 -2 It is preferable that it is Pa or higher, 1.5 × 10 -1 It is more preferable that it be Pa or higher, 2.5 × 10 -1 It is even more preferable that the bending stiffness is Pa or higher. The upper limit of the bending stiffness is not particularly limited, but for example, 5.0 × 10 -1 The bending stiffness of the artificial hair fiber can be measured, for example, using a single-strand bending tester (Kato Tech Co., Ltd. "KES-FB2-SH") with a curvature of 2.5 cm. -1 Bending speed 0.5cm -1The average value (for example, n=10) obtained when bending tests are performed at a rate of / second can be used. If the bending stiffness of the artificial hair fiber is above the lower limit, even if it contains polyvinyl chloride resin which reduces environmental impact, it will be an artificial hair fiber that has the same bending stiffness as conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin.

[0047] 3.4 Heat resistance The heat shrinkage rate of the artificial hair fibers according to this embodiment at 90°C is preferably 15% or less, more preferably 10% or less, and even more preferably 6% or less. The lower limit of the heat shrinkage rate at 90°C is not particularly limited, but can be, for example, 0%. The heat shrinkage of the artificial hair fibers at 90°C can be determined, for example, by cutting the artificial hair fibers to a length of 100 mm, measuring the fiber length before and after heating in a 90°C oven for 15 minutes, and using the average value of the values ​​calculated based on the following formula 2 (for example, n=10). (Fiber shrinkage rate [%]) = [{(Fiber length before heat treatment) - (Fiber length after heat treatment)} / (Fiber length before heat treatment)] × 100 (Equation 2) If the heat shrinkage rate of the artificial hair fibers at 90°C is below the upper limit, even if they contain polyvinyl chloride resin which reduces environmental impact, the artificial hair fibers will have the same heat resistance as conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin.

[0048] The heat shrinkage rate of the artificial hair fibers according to this embodiment at 80°C is preferably 10% or less, more preferably 2.0% or less, and even more preferably 1.5% or less. The lower limit of the heat shrinkage rate at 80°C is not particularly limited, but can be, for example, 0%. The heat shrinkage of the artificial hair fibers at 80°C can be measured under the same conditions as the measurement method for "heat shrinkage rate at 90°C" described above, except that the oven temperature is changed to 80°C. If the heat shrinkage rate of the artificial hair fibers at 80°C is below the upper limit, even if the artificial hair fibers contain polyvinyl chloride resin which can reduce environmental impact, the artificial hair fibers will have the same heat resistance as conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin as the polyvinyl chloride resin.

[0049] 3.5 Fineness The fineness of the artificial hair fibers according to this embodiment can be 30 to 80 d (denier), preferably 40 to 70 d, and more preferably 45 to 60 d. The fineness of the artificial hair fibers may be, for example, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 80 d, and may be within the range of any two of the values ​​exemplified herein.

[0050] A first embodiment of the present invention is an artificial hair fiber having a base fiber containing polyvinyl chloride resin, wherein the polyvinyl chloride resin contains plant-derived polyvinyl chloride resin. According to the first embodiment, by using a specific type of polyvinyl chloride resin, an artificial hair fiber that can reduce environmental impact can be provided. Furthermore, a second embodiment of the present invention is a method for producing artificial hair fibers having a base fiber containing polyvinyl chloride resin, wherein at least a portion of the polyvinyl chloride resin is allocated a sustainable ratio using a mass balance method, and the method includes an internal lubricant addition step in which an internal lubricant is added to the polyvinyl chloride resin to form a resin composition, and the maximum torque when the resin composition is melt-kneaded at a resin temperature of 170°C using a plastograph is 25 to 45 N·m. According to the second embodiment, when using a polyvinyl chloride resin that can reduce environmental impact, it is possible to provide a method for producing artificial hair fibers that have properties (color development, tensile properties, bending rigidity, and heat resistance) equivalent to those of conventional artificial hair fibers that use only fossil fuel-derived polyvinyl chloride resin, by adjusting the composition of the resin composition to satisfy specific parameters. [Examples]

[0051] The present invention will be described in more detail below based on the following examples. The examples described below are merely representative examples of the present invention and should not be interpreted as narrowing the scope of the invention.

[0052] <Internal lubricant addition process> Each resin composition was obtained by adding an internal lubricant to polyvinyl chloride resin (PVC) with the compositions shown in Tables 1 and 2. In Examples 1-3 and 6-14, the amount of internal lubricant added (x parts by mass) was within the range of Formula 1 below. In Formula 1, the content of plant-derived polyvinyl chloride resin in 100% by mass of polyvinyl chloride resin was defined as a% by mass.

number

[0053] The components used to obtain the resin composition are as follows: (Plant-derived polyvinyl chloride resin) • Plant-derived PVC 1: INEOS Inovin's "BIOVYN 267RC" (contains pulp-derived raw materials; 100% sustainable using the mass balance method; K value 67; apparent specific gravity 0.58 kg / dm³) 3 ) • Plant-derived PVC2: INEOS Inovin's "BIOVYN 264RC" (contains pulp-derived raw materials; 100% sustainable using the mass balance method; K value 64; apparent specific gravity 0.61 kg / dm³) 3 ) • Plant-derived PVC3: INEOS Inovin's "BIOVYN 271RC" (contains pulp-derived raw materials; 100% sustainable using the mass balance method; K value 80; apparent specific gravity 0.50 kg / dm³) 3 ) • Plant-derived PVC4: Our company's product (contains pulp-derived raw materials; 100% sustainable using the mass balance method; K value 58; apparent specific gravity 0.64 kg / dm³ 3 ) • Plant-derived PVC5: Our company's product (contains pulp-derived raw materials; 100% sustainable using the mass balance method; K value 85; apparent specific gravity 0.46 kg / dm 3 ) (Polyvinyl chloride resin derived from fossil fuels) • Fossil fuel-derived PVC: (Contains no plant-derived raw materials, no sustainable ratio allocation based on mass balance method (sustainable ratio 0%); K value 67; apparent specific gravity 0.54 kg / dm 3 ) (Internal lubricant) • Calcium stearate: "Calcium Stearate" manufactured by NOF Corporation • Zinc stearate: "Zinc Stearate" manufactured by NOF Corporation

[0054] <Spinning Process> Each resin composition was kneaded using a φ40 mm single-screw extruder to obtain resin compositions in the form of spinning pellets. The obtained pellet-shaped resin compositions were spun using a φ40 mm single-screw melt spinning machine. At this time, the cylinder temperature was 150 to 190°C and the nozzle temperature was 180 ± 15°C.

[0055] <Stretching process> The obtained unstretched artificial hair fibers were stretched at 100°C with a stretching ratio of 3.

[0056] <Surface treatment agent application process> A surface treatment agent was applied to artificial hair fibers using a roll transfer method. The roll transfer conditions were as follows: the roll radius was 125 mm, the roll was immersed in a solution containing the surface treatment agent up to a height of 20 mm from the bottom end of the roll, and the roll rotation speed was 0.2 to 8 m / min. The amount of surface treatment agent applied was 0.1 parts by mass per 100 parts by mass of base fiber.

[0057] The surface treatment agent used contains the following components: (Surface treatment agent) • Mineral oil: "Mineral Oil" manufactured by DKSH Japan Co., Ltd. • Polyoxyethylene alkyl ether: "Poly(oxyethylene) oleyl ether" manufactured by Nikko Chemicals Co., Ltd. • Alkyl alkylate: Octyl palmitate manufactured by BOC Science.

[0058] <Heat treatment process> Artificial hair fibers were placed in a heat treatment device and subjected to a heat treatment process at 115°C. The relaxation rate during heat treatment was set to 0.50 to 0.99 times. The fineness of the artificial hair fibers was 45 to 60d.

[0059] The results of the tests and evaluations conducted on each resin composition and artificial hair fiber prepared in this manner are shown in Tables 1 and 2.

[0060] [Table 1]

[0061] [Table 2]

[0062] <Plastograph> For 50g of each resin composition, the maximum torque and the time to reach the maximum torque were measured using a plastograph. Specifically, the measurements were taken under the following conditions. Measuring instrument: Brabender "Plastograph PL-2000" Resin temperature: 170℃ Measurement time: 15 minutes

[0063] <Color development> For each artificial hair fiber, a color meter (Kurabo Corporation "COLOR-7X") was used to measure the CIE1976 (L * ,a * ,b * ) In the color space, L * ,a * ,b * The value was measured.

[0064] <Tensile properties> (Tensile strength) Tensile tests were conducted on each artificial hair fiber using a tensile testing machine (Shimadzu Autograph AGS-X) with a chuck distance of 200 mm and a tensile speed of 200 mm / min. Tensile strength was calculated from the stress at fracture per unit cross-sectional area. The average value of measurements taken from 10 samples of each artificial hair fiber was calculated. (Initial tensile strength) The initial tensile strength was calculated from the stress gradient with respect to fiber strain in the elastic deformation region per unit cross-sectional area during the tensile test described above. The average value of the measurements for each of the 10 artificial hair fibers was calculated. (Elongation at break) The elongation at break was calculated from the elongation at break, relative to the value before the start of tensioning, during the tensile test described above. The average value of the measurements for each of the 10 artificial hair fibers was calculated.

[0065] <Bending stiffness> For each artificial hair fiber, a single-strand bending test was performed using a single-strand bending tester (Kato Tech Co., Ltd. "KES-FB2-SH") to test for a curvature of 2.5 cm. -1 Bending speed 0.5cm -1 A bending stiffness test was performed at [number] seconds. The average value of the measurements for each of 10 artificial hair fibers was calculated.

[0066] <Heat resistance> (Thermal shrinkage rate (90℃)) For each artificial hair fiber, it was cut to a length of 100 mm, and the fiber length was measured before and after heating in a 90°C oven (STD45 gear oven manufactured by Toyo Seiki Seisakusho Co., Ltd.) for 15 minutes. The average value of the calculated values ​​was then calculated based on the following formula 2 (n=10). (Fiber shrinkage rate [%]) = {(Fiber length before heat treatment) - (Fiber length after heat treatment)} / (Fiber length before heat treatment) × 100 (Equation 2) (Thermal shrinkage rate (80℃)) The above (heat shrinkage rate (90°C)) was measured and calculated under the same conditions, except that the oven temperature was changed to 80°C.

Claims

1. A fiber for artificial hair having a base fiber containing polyvinyl chloride resin, The polyvinyl chloride resin in question is a fiber for artificial hair, wherein the polyvinyl chloride resin includes plant-derived polyvinyl chloride resin.

2. The base material fiber further contains an internal lubricant, The artificial hair fiber according to claim 1, wherein the content of the plant-derived polyvinyl chloride resin in 100% by mass of the polyvinyl chloride resin is a% by mass, and the content of the internal lubricant in 100 parts by mass of the polyvinyl chloride resin is within the range of the following formula 1. [Math 1]

3. The polyvinyl chloride resin consists solely of the plant-derived polyvinyl chloride resin. The artificial hair fiber according to claim 2, wherein the content of the internal lubricant is 0.1 to 3.0 parts by mass per 100 parts by mass of the plant-derived polyvinyl chloride resin.

4. The artificial hair fiber according to claim 2, wherein the internal lubricant comprises at least calcium stearate and zinc stearate.

5. The artificial hair fiber according to claim 1, wherein the K value of the polyvinyl chloride resin is 60 to 80.

6. The artificial hair fiber according to claim 1, wherein the plant-derived polyvinyl chloride resin is derived from pulp.

7. A method for producing artificial hair fibers having a base fiber containing polyvinyl chloride resin, At least a portion of the aforementioned polyvinyl chloride resin is allocated a sustainable ratio using a mass balance method. The process includes an internal lubricant addition step in which an internal lubricant is added to the polyvinyl chloride resin to form a resin composition. A method for producing fibers for artificial hair, wherein the resin composition is melt-kneaded using a plastograph at a resin temperature of 170°C, and the maximum torque is 25 to 45 N·m.

8. The internal lubricant addition step includes an addition amount determination step that determines the amount of the internal lubricant to be added, The above addition amount determination step involves determining the amount of the internal lubricant added x parts by mass relative to 100 parts by mass of the polyvinyl chloride resin, A method for producing artificial hair fibers according to claim 7, wherein the content of plant-derived polyvinyl chloride resin in 100% by mass of the polyvinyl chloride resin is within the range of the following formula 1, where a is by mass. [Math 2]

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