Artificial hair and manufacturing thereof

Abstract

To provide artificial hair having natural gentle waviness like human hair.SOLUTION: An eccentric sheath-core composite fiber is obtained by composite melt spinning using polyamide 6 as the core component and a polyamide resin composition in which the polyamide 6 and an alkali-soluble polyester are mixed as the sheath component. The eccentric sheath-core composite fiber is treated with an alkaline aqueous solution to elute the alkali-soluble polyester. The eccentric sheath-core composite fiber is then dyed black in hot water to obtain artificial hair. Since the core component and the sheath component are made of the same polyamide 6, artificial hair with gentle waviness is obtained.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to artificial hair that can be used as a wig, a toupee, a hairpiece, or the like, and a method for producing the same. [Background technology]

[0002] Artificial hair has been used as a substitute for human hair. Known artificial hair is made of acrylic, polyester or polyamide fibers. In the textile industry, it has long been known that side-by-side composite fibers or eccentric core-sheath composite fibers made of different synthetic resins have latent crimping ability and shrink when heat-treated (Patent Document 1, claim 3 and paragraph 0021). For example, dyeing is generally performed in warm or hot water, so heat treatment is performed during the dyeing process, and shrinkage occurs during this process. The reason for shrinkage is that the hot water shrinkage rate differs between different synthetic resins.

[0003] It has been proposed to obtain artificial hair by utilizing such latent crimping ability. For example, Patent Document 2 proposes artificial hair that is an eccentric core-sheath type composite fiber with a flat cross section, in which the core component is a polyester resin and the sheath component is a polyamide resin. However, there is a drawback in that the crimp caused by such latent crimping ability tends to be spiral, and it is difficult to obtain a natural gentle wave like human hair.

[0004] [Patent Document 1] International Publication No. 2019 / 202993 [Patent Document 2] International Publication No. 2022 / 145114 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to obtain artificial hair having natural gentle waves like human hair. [Means for solving the problem]

[0006] The present invention relates to an artificial hair made of an eccentric sheath-core composite fiber, in which the core component is made of a polyamide resin and the sheath component is made of the same type of polyamide resin, rather than different types of synthetic resins, and the artificial hair is made of an eccentric sheath-core composite fiber, in which the core component is made of a polyamide resin and the sheath component is made of the same type of polyamide resin as the polyamide resin, and to a method for producing the artificial hair.

[0007] The artificial hair according to the present invention is formed of an eccentric core-sheath type composite fiber. The eccentric core-sheath type composite fiber has a cross-sectional shape as shown in FIG. 1, and is composed of a core component 1 and a sheath component 2, and the center of gravity of the core component 1 is offset from the center of gravity of the composite fiber. This offset of the center of gravity is expressed by the eccentricity. The eccentricity is calculated by [(r1-r) / r]×100(%), where r1 is the longest distance from the center of gravity of the core component 1 to the outer periphery of the composite fiber, and r is the longest distance from the center of gravity of the composite fiber to the outer periphery of the composite fiber. The cross-sectional shape of the composite fiber is preferably circular, and in this case, r is the radius of the composite fiber. In the present invention, the eccentricity is preferably about 3 to 20%. If the eccentricity is less than 3%, the texture will be straight or bristle-like, making it difficult to obtain artificial hair with a natural, gentle wave. If the eccentricity is more than 20%, the wave will be intense, making it difficult to obtain artificial hair with a natural, gentle wave.

[0008] The core component 1 and the sheath component 2 of the artificial hair according to the present invention are composed of the same type of polyamide resin. In the present invention, the same type of polyamide resin means that the thermal properties of the polyamide resin are almost the same. In general, it is preferable to use the same polyamide resin. As the polyamide resin, polyamide 6 (nylon 6), polyamide 66 (nylon 66), polyamide 46 (nylon 46), polyamide 12 (nylon 12), etc. are used. The polyamide resin used for the core component 1 may contain additives such as antistatic agents, flame retardants, black pigments, etc. Also, the polyamide resin used for the sheath component 2 may contain additives such as antistatic agents, flame retardants, black pigments, inorganic fine particles, etc. The mass ratio of the core component 1 to the sheath component 2 is about core component 1:sheath component 2=3-7:7-3. The reason for using the polyamide resin is that it has a high affinity for water.

[0009] It is preferable that the outer peripheral surface of the sheath component 2 of the artificial hair according to the present invention is uneven. When the outer peripheral surface of the sheath component 2 is uneven, the luster of the artificial hair surface can be suppressed, and the texture becomes closer to that of human hair. To form the unevenness, for example, there is a method of mixing a soluble resin in advance with the sheath component 2 and dissolving the soluble resin. Furthermore, this method may be used in combination with a method of making inorganic fine particles exist in the sheath component 2. As the inorganic fine particles, conventionally known ones can be used, and those having a particle size of about 0.001 to 5 μm can be used. Specifically, titanium oxide fine particles are used.

[0010] The artificial hair according to the present invention has a natural gentle wave like human hair. Such a wave is automatically generated when the artificial hair is manufactured. That is, in order to manufacture the artificial hair, it is generally necessary to dye it black or brown. The dyeing is generally performed in warm or hot water, and the eccentric core-sheath type composite fiber is heat-treated at the same time as the dyeing. At this time, the core component 1 and the sheath component 2 of the eccentric core-sheath type composite fiber are made of the same type of polyamide resin, so they shrink at the same shrinkage rate. Although the shrinkage rates are the same, since the core component 1 is eccentric, a stress difference occurs between the thick and thin parts of the sheath component 2. This stress difference causes a gentle wave. In the present invention, in addition to the heat treatment by dyeing, a gentle wave may be generated by heat treatment in a drying process or a separate heat treatment process. Examples of such gentle waves include those shown in Figures 2 to 5. 2 and 4 are photographs showing examples of wavy strands of artificial hair, and FIGS. 3 and 5 are photographs showing examples of wavy strands of artificial hair when bundled together.

[0011] The artificial hair according to the present invention can be produced by obtaining an eccentric sheath-core composite fiber having a core component made of a polyamide resin and a sheath component made of the same type of polyamide resin as the polyamide resin, and then subjecting the eccentric sheath-core composite fiber to a heat treatment. In particular, a preferred method for producing the artificial hair according to the present invention is as follows. That is, the method for producing the artificial hair according to the present invention comprises obtaining an eccentric sheath-core composite fiber having a core component made of a polyamide resin and a sheath component made of a polyamide resin composition containing the same type of polyamide resin as the polyamide resin and a soluble resin, eluting the soluble resin from the sheath component of the eccentric sheath-core composite fiber, and then subjecting the fiber to a heat treatment.

[0012] The eccentric sheath-core composite fiber can be obtained by a conventionally known composite melt spinning method. That is, the polyamide resin as the core component and the same type of polyamide resin as the sheath component are supplied to a composite melt spinning hole, discharged, and drawn. The polyamide resin as the core component and the polyamide resin as the sheath component are preferably the same. The obtained eccentric sheath-core composite fiber is then dyed, and since heat is applied in this dyeing process, the eccentric sheath-core composite fiber forms a gentle undulation. In order to form a gentle undulation, the eccentric sheath-core composite fiber in the dyeing process is preferably wound in a skein. The skein winding refers to a state in which the eccentric sheath-core composite fiber is wound around a skein frame, which is a spindle tool such as a letter V-shaped spindle, and then the frame is removed. In this state, almost no tension is applied to the eccentric sheath-core composite fiber, so that a gentle undulation is easily formed.

[0013] As the polyamide resin for the sheath component, it is preferable to use a polyamide resin composition containing the same type of polyamide resin as the core component and a soluble resin. Here, the soluble resin is a resin that dissolves under conditions in which the polyamide resin does not dissolve. For example, an alkali-soluble polyester resin dissolves in an alkaline aqueous solution, but the polyamide resin does not dissolve in an alkaline aqueous solution. Therefore, the alkali-soluble polyester resin is an example of a soluble resin. The blending ratio of the soluble resin in the polyamide resin composition is preferably about 10 to 35 parts by mass per 100 parts by mass of the polyamide resin. The polyamide resin for the core component and the polyamide resin composition for the sheath component are composite melt spun to obtain an eccentric core-sheath type composite fiber. In this eccentric core-sheath type composite fiber, the core component is made of a polyamide resin and the sheath component is made of a polyamide resin composition. When such an eccentric core-sheath type composite fiber is immersed in an alkaline aqueous solution, the alkali-soluble polyester resin is dissolved, and depressions and holes are formed from the surface of the sheath component 2 to the interface of the core component 1. This makes it possible to suppress the gloss of the surface of the resulting artificial hair. As the alkali-soluble polyester resin, a conventionally known one can be used, for example, one that is mainly composed of terephthalic acid and ethylene glycol, and is copolymerized with other carboxylic acid components such as isophthalic acid and / or other alcohol components. It goes without saying that the present invention is not limited to the alkali-soluble polyester resin, and other soluble resins may also be used.

[0014] In addition, inorganic fine particles may be added to the same type of polyamide resin as the core component as the polyamide resin that becomes the sheath component. The inorganic fine particles are not dissolved but remain in the sheath component. The inorganic fine particles are preferably added in an amount of about 0.1 to 1 part by mass per 100 parts by mass of polyamide resin. Furthermore, inorganic fine particles may be added to a polyamide resin composition that contains the same type of polyamide resin as the core component and a soluble resin.

[0015] Even when a polyamide resin composition is used as the sheath component or when inorganic fine particles are added, artificial hair is generally obtained through a process of dyeing the fiber black. In the dyeing process, heat is applied to the eccentric core-sheath type composite fiber, and the fiber is heat-treated. This results in the formation of a natural, gentle wave like that of human hair.

[0016] The artificial hair according to the present invention preferably has a diameter similar to that of human hair, 0.04 to 0.1 mm, and more preferably about 0.08 mm. The cross-sectional shape of the artificial hair according to the present invention is preferably circular or elliptical. In particular, it is preferably circular, similar to the shape of Asian human hair. The artificial hair according to the present invention is used as a wig, or a false hair by being tied up or implanted. Effect of the Invention

[0017] The artificial hair according to the present invention is made of an eccentric core-sheath type composite fiber, the core component of which is a polyamide resin and the sheath component of which is a polyamide resin having the same thermal properties as the polyamide resin. Therefore, when the artificial hair according to the present invention is subjected to a heat treatment, gentle waves are formed, and an artificial hair like human hair is obtained. EXAMPLES

[0018] Example 1 As the core component, a polyamide resin was prepared by adding 7% by mass of an antistatic agent ("Pelectron AS" manufactured by Sanyo Kasei Chemicals Co., Ltd.) to polyamide 6 having a melting point of 215°C. On the other hand, as the sheath component, a polyamide resin composition was prepared by mixing the polyamide 6 used in the core component and an alkali-soluble polyester in a mass ratio of polyamide 6:alkali-soluble polyester = 80:20. The alkali-soluble polyester was obtained by copolymerizing 48 mol% terephthalic acid, 2 mol% isophthalic acid, 38 mol% ethylene glycol, and 12 mol% polyethylene glycol. Then, the core component and the sheath component were supplied in a ratio of 50 parts by mass and 50 parts by mass, and a composite yarn was discharged from a composite melt spinning hole (hole diameter 0.6 mm) at a spinning temperature of 285°C. The composite yarn was then cooled with water at 50°C, and subsequently subjected to a first-stage drawing at a draw ratio of 2.6 times in a 90°C water bath, and then a second-stage drawing at a draw ratio of 1.53 times in a dry heat heater at 130°C. It was then subjected to a relaxation heat treatment at a temperature of 140°C to obtain an eccentric sheath-core composite fiber. This eccentric sheath-core composite fiber had a diameter of 0.08 mm, a mass ratio of the core component to the sheath component of 1:1, and an eccentricity of 7.6%.

[0019] The eccentric core-sheath composite fiber was wound into a skein of 113 cm length and 250 g weight using a skein raising machine (Kyoritsu Machinery Manufacturing Co., Ltd.). The skein was loaded and set in a package dyeing machine (Hisaka Manufacturing Co., Ltd.), and then the alkali-soluble polyester in the sheath component was eluted using 40 g / l of sodium hydroxide aqueous solution at a bath ratio of 1:30, a temperature of 95°C, and a time of 90 minutes. After that, it was dehydrated and washed with water, and then dyed using a black dye (DyStar Japan's "Mitsui Nylon Black") 5% omf, acetic acid 0.2 cc / l, and a dyeing assistant (Marubishi Yuka Kogyo's "Levelan NKD") 2% omf at a bath ratio of 1:30, a temperature of 100°C, and a time of 30 minutes. After that, it was dehydrated and washed with water to obtain black artificial hair.

[0020] Example 2 Artificial hair was obtained in the same manner as in Example 1, except that the sheath component was the polyamide resin composition used in Example 1 to which 0.3 mass % of titanium oxide (average particle size 0.16 μm) was added.

[0021] Example 3 Artificial hair was obtained in the same manner as in Example 1, except that the core component was the polyamide resin used in Example 1 to which 0.06% by mass of carbon black had been added.

[0022] Example 4 In Example 2, after dyeing, the skeins were dehydrated and washed with water, and a feel improving agent (Nicca Chemical's "Evaphanol N-33" 1% omf) was used to improve the feel at a bath ratio of 1:30, at a temperature of 100°C, and for 30 minutes, to obtain black artificial hair.

[0023] Example 5 Artificial hair was obtained in the same manner as in Example 1, except that the mass ratio of polyamide 6 to alkali-soluble polyester in the polyamide resin composition, which was the sheath component used in Example 1, was changed to polyamide 6:alkali-soluble polyester=70:30.

[0024] The black artificial hair obtained in Example 1 had gentle wavy shapes as shown in Figures 2 and 3. The black artificial hair obtained in Example 2 had gentle wavy shapes as shown in Figures 4 and 5. Figure 6 is an SEM photograph showing an enlarged side of the black artificial hair obtained in Example 1, Figure 7 is an SEM photograph showing an enlarged cross section of the black artificial hair obtained in Example 1, and Figure 8 is an SEM photograph showing a further enlargement of a part of the cross section. The artificial hair obtained in Examples 3 to 5 also had similar gentle wavy shapes. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a schematic cross-sectional view of an example of an eccentric sheath-core type composite fiber used in the present invention. [Diagram 2] 1 is a side view photograph of each individual strand of artificial hair obtained in Example 1. [Diagram 3] 1 is a side photograph of the artificial hair obtained in Example 1 in a bundled state. [Figure 4] 1 is a side view photograph of each individual strand of artificial hair obtained in Example 2. [Diagram 5] 1 is a side photograph of the artificial hair obtained in Example 2 in a bundled state. [Figure 6] 2 is an enlarged SEM photograph of the side of the artificial hair obtained in Example 1. [Figure 7] 2 is an enlarged SEM photograph of the cross section of the artificial hair obtained in Example 1. [Figure 8] 2 is an SEM photograph showing a further enlarged portion of the cross section of the artificial hair obtained in Example 1. [Explanation of symbols]

[0026] 1 core component 2 Sheath component

Claims

1. The artificial hair is made of an eccentric core-sheath type composite fiber, the core component being made of a polyamide resin and the sheath component being made of the same type of polyamide resin as the polyamide resin.

2. 2. The artificial hair according to claim 1, wherein the polyamide resin of the core component is the same as the polyamide resin of the sheath component.

3. 2. The artificial hair according to claim 1, wherein the cross-sectional shape of the eccentric core-sheath type composite fiber is approximately circular.

4. 2. The artificial hair according to claim 1, wherein the eccentric core-sheath type composite fiber has an uneven surface.

5. 2. The artificial hair according to claim 1, wherein the sheath component contains inorganic fine particles.

6. 2. The artificial hair according to claim 1, which is dyed black.

7. A wig, toupee or false hair comprising the artificial hair according to any one of claims 1 to 6.

8. A method for producing artificial hair, comprising obtaining an eccentric sheath-core composite fiber in which a core component is a polyamide resin and a sheath component is made of the same type of polyamide resin as the polyamide resin, and then subjecting the eccentric sheath-core composite fiber to a heat treatment.

9. A method for producing artificial hair, comprising the steps of obtaining an eccentric sheath-core composite fiber having a core component made of a polyamide resin and a sheath component made of a polyamide resin composition containing the same type of polyamide resin as the polyamide resin and a soluble resin, eluting the soluble resin from the sheath component of the eccentric sheath-core composite fiber, and then carrying out a heat treatment.

10. 10. The method for producing artificial hair according to claim 9, wherein the soluble resin is an alkali-soluble polyester resin.

11. The method for producing artificial hair according to any one of claims 8 to 10, wherein the eccentric core-sheath type composite fiber is subjected to a heat treatment in a skein-wound state.

12. The method for producing artificial hair according to any one of claims 8 to 10, wherein the heat treatment is carried out in a dyeing step.

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