Acrylic fibers for artificial hair, acrylic crimped fibers for artificial hair, headwear products containing the same, and methods for manufacturing the same.

Abstract

The present invention relates to acrylic fiber for artificial hair, the acrylic fiber being configured from an acrylic copolymer, while having a torsional rigidity of 0.3 to 2.0 mg∙cm2 and a dry heat shrinkage of 30% to 70% if subjected to a dry heat treatment at 90°C to 180°C for 30 minutes. In addition, one or more embodiments of the present invention relate to acrylic crimped fiber for artificial hair, the acrylic crimped fiber being configured from an acrylic copolymer, while having a number of crimps of 10 or more per 10 cm and a crimp height of 1.5 mm or more, wherein at least two crimps among 10 consecutive crimps are different from each other in the crimp width, crimp height and crimp direction.

Description

[Technical Field]

[0001] The present invention relates to acrylic fibers for artificial hair used in headwear products, acrylic crimped fibers for artificial hair, headwear products containing the same, and methods for manufacturing the same. [Background technology]

[0002] Traditionally, acrylic fibers have been used as artificial hair in headwear products because they are soft and have a texture similar to human hair. For example, Patent Document 1 proposes acrylic fibers for artificial hair and headwear products using the same, which increase volume and improve texture and twistability by forming a specific cross-sectional shape. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2006 / 135060 [Overview of the project] [Problems that the invention aims to solve]

[0004] As a head accessory, braided artificial hair is a well-known product. By attaching the braid to one's own hair, it is possible to enjoy hair styling. For wearers with uneven hair length, especially young children whose hair has not yet grown in completely, it is desirable to give the artificial hair uneven or irregular crimps to improve its blend with the wearer's own hair.

[0005] However, when conventional acrylic fibers, such as the acrylic fibers disclosed in Patent Document 1, are subjected to irregular crimping, they have a superior feel, but they lack volume and have difficulty forming a crimp that blends well with natural hair.

[0006] To solve the aforementioned problems, the present invention provides an acrylic fiber for artificial hair, an acrylic crimped fiber for artificial hair, a headwear product containing the same, and a method for manufacturing the same, which can exhibit a crimp that has a good feel, high volume, and excellent blendability with natural hair, even when irregular crimps are applied. [Means for solving the problem]

[0007] One or more embodiments of the present invention are acrylic fibers for artificial hair composed of an acrylic copolymer, wherein the dry heat shrinkage rate when dry heat treated at a temperature of 90°C to 180°C for 30 minutes is 30% to 70%, and the torsional rigidity is 0.3 mg·cm². 2 More than 2.0 mg cm 2 The following concerns acrylic fibers for artificial hair.

[0008] One or more embodiments of the present invention relate to an acrylic crimped fiber for artificial hair, composed of an acrylic copolymer, wherein the crimp count is 10 or more per 10 cm, the average crimp height per 10 cm of fiber is 1.5 mm or more, at least two of the 10 consecutive crimps have different crimp widths, at least two of the crimps have different crimp heights, and the fiber has two or more different crimp directions.

[0009] One or more embodiments of the present invention relate to headwear products containing the acrylic fiber for artificial hair or the acrylic crimped fiber for artificial hair.

[0010] One or more embodiments of the present invention relate to a method for producing acrylic fibers for artificial hair, comprising the steps of: wet spinning a spinning solution containing an acrylic copolymer using a spinning nozzle to obtain a coagulated yarn; a primary stretching step of wet stretching the obtained coagulated yarn; and a secondary stretching step of dry stretching the obtained primary stretched yarn, wherein no relaxation treatment is performed after the secondary stretching step.

[0011] One or more embodiments of the present invention relate to a method for manufacturing acrylic crimped fibers for artificial hair, the method including a step of wet spinning a spinning solution containing an acrylic copolymer using a spinning nozzle to obtain a coagulated yarn, a primary stretching step of wet stretching the obtained coagulated yarn, a secondary stretching step of dry stretching the obtained primary stretched yarn, and a step of heat shrinking the obtained secondary stretched yarn at a temperature of 90°C or higher and 150°C or lower for 5 minutes or longer and 60 minutes or shorter in a non-tension state to impart crimps.

Advantages of the Invention

[0012] According to one or more embodiments of the present invention, it is possible to provide acrylic fibers for artificial hair that can exhibit crimps with good touch, high volume, and excellent compatibility with natural hair even when irregular crimps are imparted. Moreover, according to one or more embodiments of the present invention, it is possible to provide acrylic crimped fibers for artificial hair that have irregular crimps imparted thereto, exhibit crimps with good touch, high volume, and excellent compatibility with natural hair. Also, according to the manufacturing method of one or more embodiments of the present invention, it is possible to obtain acrylic fibers for artificial hair that can exhibit crimps with good touch, high volume, and excellent compatibility with natural hair even when irregular crimps are imparted. Furthermore, according to the manufacturing method of one or more embodiments of the present invention, it is possible to obtain acrylic crimped fibers for artificial hair that have irregular crimps imparted thereto, exhibit crimps with good touch, high volume, and excellent compatibility with natural hair.

Brief Description of the Drawings

[0013] [Figure 1] It is a schematic cross-sectional view of a fiber cross-section in the shape of an anchor Y for one example. [Figure 2] It is a schematic cross-sectional view of a fiber cross-section in the shape of a C for one example. [Figure 3] It is a schematic cross-sectional view of a fiber cross-section in the shape of a 6 for one example. [Figure 4] It is a schematic cross-sectional view for explaining each dimension in a fiber cross-section in the shape of an anchor Y for one example. [Figure 5] This is a schematic cross-sectional view illustrating the dimensions of a C-shaped fiber cross-section in one example. [Figure 6] This is a schematic cross-sectional view illustrating the dimensions of a six-shaped fiber cross-section in one example. [Figure 7] This is a schematic cross-sectional view of an example of a wet spinning nozzle. [Figure 8] This is a schematic cross-sectional view of an example of a wet spinning nozzle. [Figure 9] This is a schematic cross-sectional view of an example of a wet spinning nozzle. [Figure 10] This is a schematic cross-sectional view of an example of a wet spinning nozzle. [Figure 11] This is a schematic diagram showing the appearance of an acrylic crimped fiber with irregular crimp. [Figure 12] This is a schematic diagram illustrating the crimp height and crimp width in an example of an acrylic crimped fiber. [Figure 13] This is a cross-sectional photograph (400x magnification) of the acrylic fiber from Example 1. [Figure 14] This is a cross-sectional photograph (400x magnification) of the acrylic fiber from Example 2. [Figure 15] This is a cross-sectional photograph (400x magnification) of the acrylic fiber from Example 3. [Figure 16] This is a cross-sectional photograph (400x magnification) of the acrylic fiber in Comparative Example 1. [Figure 17] This is a cross-sectional photograph (400x magnification) of the acrylic fiber in Comparative Example 6. [Modes for carrying out the invention]

[0014] (Acrylic fiber for artificial hair) The inventors of the present invention have found that, in acrylic fibers for artificial hair composed of acrylic copolymers, by adjusting the dry heat shrinkage rate and torsional rigidity within a predetermined range when dry heat treatment is performed at a temperature of 90°C to 180°C for 30 minutes, specifically by increasing the dry heat shrinkage rate and decreasing the torsional rigidity, it is possible to produce crimps that have a good feel, high volume, and excellent blendability with natural hair, even when irregular crimps are imparted. In this specification, "irregular crimps" means that among 10 consecutive crimps, at least two crimps have different crimp widths, at least two crimps have different crimp heights, and there are two or more different crimp directions.

[0015] Acrylic fibers for artificial hair have a dry heat shrinkage rate (hereinafter also simply referred to as "dry heat shrinkage rate") of 30% to 70% when dry heat treated at a temperature of 90°C to 180°C for 30 minutes. A dry heat shrinkage rate of 30% or higher allows the acrylic fibers for artificial hair to exhibit high volume and a crimp that blends well with natural hair, even when irregular crimping is applied. Furthermore, a dry heat shrinkage rate of 70% or lower provides a natural feel and appearance.

[0016] The upper limit of the dry heat shrinkage rate of acrylic fibers for artificial hair when subjected to dry heat treatment at a temperature of 90°C to 180°C for 30 minutes is preferably 65% ​​or less, 60% or less, 55% or less, 50% or less, 49% or less, 48% or less, 47% or less, or 46% or less. The lower limit of the dry heat shrinkage rate of acrylic fibers for artificial hair when subjected to dry heat treatment at a temperature of 90°C to 180°C for 30 minutes is preferably 33% or more, 35% or more, or 37% or more. In acrylic fibers for artificial hair, the preferred range for the dry heat shrinkage rate when dry heat treatment is performed at a temperature of 90°C to 180°C for 30 minutes may be any combination of the upper and lower limits described above. More specifically, the dry heat shrinkage rate of acrylic fibers for artificial hair when subjected to dry heat treatment at a temperature of 90°C to 180°C for 30 minutes is preferably 33% to 60%, more preferably 35% to 50%, and even more preferably 37% to 46%.

[0017] It is preferable that the dry heat shrinkage rate of acrylic fibers for artificial hair when dry heat treatment is performed at a temperature of 95°C to 170°C for 30 minutes satisfies the range described above, more preferably that the dry heat shrinkage rate when dry heat treatment is performed at a temperature of 100°C to 160°C for 30 minutes satisfies the range described above, even more preferably that the dry heat shrinkage rate when dry heat treatment is performed at a temperature of 110°C to 150°C for 30 minutes satisfies the range described above, and particularly preferably that the dry heat shrinkage rate when dry heat treatment is performed at 120°C for 30 minutes satisfies the range described above.

[0018] In this specification, the dry heat shrinkage rate is calculated using the following formula 1, based on the fiber length of the fiber bundle before and after heat treatment, by dry heat treatment of a fiber bundle of a predetermined fiber in a tension-free state for 30 minutes in a soaking dryer set to a predetermined temperature. In the following formula 1, La is the fiber length of the fiber bundle under a 50g load before heat treatment, and Lb is the fiber length of the fiber bundle under a 50g load after heat treatment. [Formula 1] Dry heat shrinkage rate (%)=(La-Lb) / La×100

[0019] The torsional rigidity of the acrylic fiber for artificial hair is 0.3 mg·cm. 2 More than 2.0 mg cm 2 The following is the torsional rigidity: 2.0 mg·cm 2 As a result of the following conditions, even when irregular crimping is applied, the acrylic fibers for artificial hair can exhibit high volume and a crimp that blends well with natural hair. Furthermore, the torsional rigidity is 0.3 mg·cm². 2 This increases the strength against external forces. In this specification, "torsional rigidity" is measured under the conditions of a torsional rotation of ±3 turns and a torsional speed of 12° / second, and can be measured specifically as described in the examples.

[0020] In the case of acrylic fibers for artificial hair, the lower limit of the torsional rigidity is preferably 0.4 mg·cm 2 or more, 0.5 mg·cm 2 or more, 0.6 mg·cm 2 or more, 0.7 mg·cm 2 or more, or 0.8 mg·cm 2 or more. In the case of acrylic fibers for artificial hair, the upper limit of the torsional rigidity is preferably 1.95 mg·cm 2 or less, 1.90 mg·cm 2 or less, 1.85 mg·cm 2 or less, 1.80 mg·cm 2 or less, 1.75 mg·cm 2 or less, or 1.70 mg·cm 2 or less. In the case of acrylic fibers for artificial hair, any combination of the above-mentioned upper and lower limits may be the preferable range of the torsional rigidity. More specifically, the torsional rigidity of the acrylic fibers for artificial hair is preferably 0.4 mg·cm 2 or more and 1.9 mg·cm 2 or less, and more preferably 0.5 mg·cm 2 or more and 1.7 mg·cm 2 or less.

[0021] The fineness of the acrylic fibers for artificial hair is not particularly limited, but from the viewpoint of being suitably used as artificial hair, it is preferably 25 dtex or more and 95 dtex or less, more preferably 30 dtex or more and 75 dtex or less, and even more preferably 35 dtex or more and 65 dtex or less.

[0022] The cross-sectional shape of acrylic fibers for artificial hair is not particularly limited, but examples include Y-shaped, anchor Y-shaped, C-shaped, figure-six, dumbbell-shaped, horseshoe-shaped, elliptical, and circular. In this specification, the cross-section of the fiber refers to the cross-sectional surface. It is preferable to have voids from the viewpoint of generating sufficient volume when crimp is applied. It is more preferable for acrylic fibers for artificial hair to have one or more cross-sectional shapes selected from the group consisting of anchor Y-shaped, C-shaped, and figure-six, from the viewpoint of easily satisfying the above-mentioned range of torsional rigidity and generating sufficient volume when crimp is applied. It is even more preferable for acrylic fibers for artificial hair to have an anchor Y-shaped shape from the viewpoint of further improving the tactile feel.

[0023] The anchor-shaped Y-shaped fiber cross-section is composed of, for example, three T-shaped projections radiating from the center, with the upper edges of the T-shaped projections being arc-shaped, bulging away from the center. "Arc-shaped" refers to all shapes similar to an arc. For example, it includes not only perfectly circular arcs, but also curved shapes including parts of ellipses, and other shapes considered identical to an arc from a common technical standpoint, and may even include partially straight sections. Furthermore, the arc may or may not be symmetrical.

[0024] Figure 1 shows a schematic cross-sectional view of an acrylic fiber for artificial hair having an anchor-shaped Y-shaped fiber cross-section. The acrylic fiber for artificial hair 1 has a cross-section composed of three T-shaped projections 3 that radiate from a central part 2, and the upper edge (part) 4 of the T-shaped projections is an arc shape that bulges away from the central part 2. The T-shaped projections 3 have an upper edge (part) 4 and a lower projection 5. The central part 2 may have a roughly circular or roughly elliptical shape.

[0025] In acrylic fibers for artificial hair having an anchor-shaped Y-shaped fiber cross-section, although not particularly limited, from the viewpoint of increasing volume, for example, the distance between adjacent ends of the upper sides of adjacent T-shaped protrusions is preferably 16.0 μm or more. Also, in acrylic fibers for artificial hair, although not particularly limited, from the viewpoint of improving tactile feel, for example, the distance between adjacent ends of the upper sides of adjacent T-shaped protrusions is preferably 50.0 μm or less, and more preferably 35.0 μm or less. In Figure 4, the distance between adjacent ends of the upper sides of adjacent T-shaped protrusions is indicated by W.

[0026] In acrylic fibers for artificial hair having an anchor-shaped Y-shaped fiber cross-section, although not particularly limited, for example, from the viewpoint of further increasing twistability and volume, the thickness of the upper part of the T-shaped projection is preferably 10% to 50% of the circumscribed circle radius of the fiber cross-section, and more preferably 25% to 45%. In this specification, the thickness of the upper part of the T-shaped projection means the vertical distance from the apex of the upper part of the T-shaped projection to the straight line connecting the two intersection points of the upper part of the T-shaped projection and the lower part of the T-shaped projection. In this specification, the apex of the upper part of the T-shaped projection is the furthest from the center point of the fiber cross-section. In Figure 4, the thickness of the upper part of the T-shaped projection is indicated by H.

[0027] In an acrylic fiber for artificial hair having an anchor-shaped Y-shaped fiber cross-section, although not particularly limited, for example, from the viewpoint of further increasing twistability and volume, the maximum length of the upper part of the T-shaped projection is preferably 1.5 to 4 times the minimum length of the upper part of the T-shaped projection, and more preferably 1.9 to 2.6 times. In this specification, the maximum length of the upper part of the T-shaped projection means the length between the two ends of the upper part of the T-shaped projection, and the minimum length of the upper part of the T-shaped projection means the length of the straight line connecting the two intersection points of the upper part of the T-shaped projection and the lower projection of the T-shaped projection. In Figure 4, the maximum length of the upper part of the T-shaped projection is indicated by Lx, and the minimum length of the upper part of the T-shaped projection is indicated by Ln.

[0028] In acrylic fibers for artificial hair having an anchor-shaped Y-shaped fiber cross-section, although not particularly limited, the circumscribed circle radius in the fiber cross-section is preferably 45.0 μm or more and 60.0 μm or less, for example, from the viewpoint of further enhancing volume and tactile feel. The circumscribed circle in the fiber cross-section refers to the circle passing through the vertices of the upper edges of the three T-shaped protrusions. In Figure 4, the circumscribed circle radius is indicated by D.

[0029] In acrylic fibers for artificial hair having an anchor-shaped Y-shaped fiber cross-section, although not particularly limited, from the viewpoint of preventing cracking of the fiber cross-section and increasing volume, the width of the T-shaped projection in the fiber cross-section is preferably 11.0 μm to 26.0 μm, and more preferably 12.0 μm to 20.0 μm. In Figure 4, the width of the T-shaped projection is indicated by A.

[0030] Figure 2 is a schematic cross-sectional view of an acrylic fiber for artificial hair having a C-shaped cross-section. In the C-shaped fiber cross-section shown in Figure 2, the two ends of the C are separated from each other and form an opening, but the two ends of the C may be in contact with each other.

[0031] Figure 3 is a schematic cross-sectional view of an acrylic fiber for artificial hair having a six-shaped cross-section as an example. In this specification, the six-shaped shape can also be described as a modified C-shape, specifically a shape in which one end of the C-shape is located inward from the other end. In the six-shaped fiber cross-section shown in Figure 3, the two ends of the six-shaped shape are separated from each other, forming an opening, but the two ends of the six-shaped shape may be in contact with each other.

[0032] In acrylic fibers for artificial hair having a C-shaped or six-shaped fiber cross-section, although not particularly limited, from the viewpoint of further improving volume and texture, for example, the diameter of the circumscribed circle of the fiber cross-section (hereinafter also referred to as the circumscribed circle diameter) is preferably 75 μm or more and 100 μm or less, and more preferably 80 μm or more and 95 μm or less. In Figures 5 and 6, the circumscribed circle diameter is indicated by R1.

[0033] In acrylic fibers for artificial hair having a C-shaped or hexagonal fiber cross-section, although not particularly limited, from the viewpoint of making it easier to achieve the torsional rigidity within the above range and further improving volume and tactile feel, the diameter of the assumed inscribed circle of the hollow portion of the fiber cross-section (hereinafter also referred to as the inscribed circle diameter) is preferably 30 μm or more and 50 μm or less, and more preferably 32 μm or more and 48 μm or less. In Figures 5 and 6, the inscribed circle diameter is indicated by R2.

[0034] In acrylic fibers for artificial hair having a C-shaped or six-shaped fiber cross-section, although not particularly limited, the thickness of the fiber cross-section is preferably 10 μm to 26 μm, and more preferably 11 μm to 25 μm, from the viewpoint of easily satisfying the above-mentioned range of torsional rigidity and further improving volume and tactile feel. In Figures 5 and 6, the thickness is indicated by t.

[0035] In acrylic fibers for artificial hair having a C-shaped fiber cross-section, although not particularly limited, the distance between the two ends of the fiber cross-section is preferably 10 μm or less, and more preferably 5 μm or less, from the viewpoint of further improving volume and tactile feel. In Figure 5, the distance between the two ends of the fiber cross-section is indicated by W. Note that if the two ends of the C-shaped fiber cross-section are touching each other, W is 0 μm. In one or more embodiments of the present invention, if the fiber cross-section has a six-shape, the distance between the two ends of the fiber cross-section is 0 μm.

[0036] Acrylic fibers for artificial hair are not particularly limited, but from the viewpoint of producing sufficient volume when crimped, the porosity of the fiber cross-section is preferably 20% to 50%, more preferably 30% to 50%, and even more preferably 35% to 45%. In this specification, the area of ​​the circumscribed circle of the fiber cross-section and the area of ​​the fiber cross-section are calculated, and the porosity is determined by the following formula 2. The area of ​​the circumscribed circle of the fiber cross-section is the area of ​​a circle whose diameter is the longest line segment among the line segments connecting any two points on the outer circumference of the fiber cross-section. [Formula 2] Porosity (%) = 100 × (Area of ​​the circumscribed circle of the fiber cross-section - Area of ​​the fiber cross-section) / Area of ​​the circumscribed circle of the fiber cross-section

[0037] Acrylic fibers for artificial hair do not necessarily need to have the same fineness, cross-sectional shape, and cross-sectional size; fibers with different fineness, cross-sectional shape, and cross-sectional size may be mixed together.

[0038] The acrylic copolymer constituting the acrylic fibers for artificial hair is not particularly limited. For example, an acrylic copolymer containing less than 95% by weight of acrylonitrile and more than 5% by weight of other monomers can be used. Preferably, an acrylic copolymer containing less than 80% by weight of acrylonitrile and more than 20% by weight of other monomers can be used. As the other monomers, monomers copolymerizable with acrylonitrile can be used as appropriate. Specifically, it is more preferable that the acrylic copolymer constituting the acrylic fibers for artificial hair contains 29.5% to 79.5% by weight of acrylonitrile, 20% to 70% by weight of vinyl chloride and / or vinylidene chloride, and 0.5% to 5% by weight of a sulfonic acid group-containing vinyl monomer. In other words, it is more preferable that the acrylic copolymer is obtained by polymerizing a monomer mixture totaling 100% by weight, which includes 29.5% to 79.5% by weight of acrylonitrile, 20% to 70% by weight of vinyl chloride and / or vinylidene chloride, and 0.5% to 5% by weight of a sulfonic acid group-containing vinyl monomer. When the acrylic copolymer has an acrylonitrile content of 29.5% to 79.5% by weight, it exhibits good heat resistance. When the acrylic copolymer has a vinyl chloride and / or vinylidene chloride content of 20% to 70% by weight, it exhibits good flame retardancy. The inclusion of 0.5% to 5% by weight of a sulfonic acid group-containing vinyl monomer in the acrylic copolymer increases its hydrophilicity. More preferably, the acrylic copolymer contains 34.5% to 74.5% by weight of acrylonitrile, 25% to 65% by weight of vinyl chloride and / or vinylidene chloride, and 0.5% to 5% by weight of a sulfonic acid group-containing vinyl monomer; particularly preferably, it contains 39.5% to 74.5% by weight of acrylonitrile, 25% to 60% by weight of vinyl chloride, and 0.5% to 5% by weight of a sulfonic acid group-containing vinyl monomer. From the viewpoint of superior tactile feel, it is preferable that the acrylic copolymer contains vinyl chloride.

[0039] The sulfonic acid group-containing vinyl monomer is not particularly limited, but for example, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, isoprene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, and their sodium salts and other metal salts and amine salts can be used. The sulfonic acid group-containing vinyl monomer may be used individually or in combination of two or more.

[0040] Acrylic fibers for artificial hair may contain other additives to improve fiber properties as needed, as long as they do not hinder the effects of the present invention. Examples of such additives include gloss modifiers such as titanium dioxide, silicon dioxide, cellulose esters and ethers of cellulose derivatives including cellulose acetate, colorants such as organic pigments, inorganic pigments and dyes, stabilizers to improve light resistance and heat resistance, fiber consolidators such as urethane polymers and cationic ester polymers to improve processability during braiding and twisting, inorganic or organic deodorants to capture isovaleric acid, an odor component generated from the scalp, and fragrances to impart a citrus or other scent to the artificial hair fibers.

[0041] (Method for manufacturing acrylic fibers for artificial hair) The acrylic fibers for artificial hair described above can be produced, for example, by wet spinning a spinning solution containing an acrylic copolymer. The spinning solution can be obtained, for example, by dissolving an acrylic copolymer in an organic solvent. The acrylic copolymers described above can be used as appropriate.

[0042] The organic solvent is not particularly limited, and any good solvent for acrylic copolymers can be used as appropriate. Examples include methyl sulfoxide (DMSO), dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), and acetone. For versatility, acetone may also be used. The spinning solution may contain a small amount of water, for example, 1.5% to 4.8% by weight of water.

[0043] The spinning solution may, if necessary, contain other additives to improve fiber properties, as long as they do not hinder the effects of the present invention. Examples of such additives include gloss modifiers such as titanium dioxide, silicon dioxide, cellulose derivatives including cellulose acetate esters and ethers, colorants such as organic pigments, inorganic pigments and dyes, and stabilizers to improve light resistance and heat resistance.

[0044] A method for producing acrylic fibers for artificial hair preferably includes at least a solidification step, a primary stretching step, and a secondary stretching step, and preferably no relaxation treatment is performed after the secondary stretching step. By not performing a relaxation treatment on the fibers, fibers with a high dry heat shrinkage rate can be obtained. In this specification, "relaxation treatment" means a relaxation treatment that is normally performed in the field of fibers, for example, heat treatment at a temperature of 100°C to 200°C so that the fibers shrink in the fiber axis direction. The percentage of fiber shrinkage in the relaxation treatment is indicated by the relaxation rate. The relaxation rate in the relaxation treatment is usually 5% or more. A relaxation rate of 5% means that the fiber has shrunk by 5% due to the relaxation treatment, that is, the fiber length of the fiber after the relaxation treatment is 95% of the fiber length of the fiber before the relaxation treatment.

[0045] First, in the coagulation process, the spinning solution is discharged into the coagulation bath through a spinning nozzle and coagulated to form a yarn (coagulated yarn).

[0046] The nozzle used for wet spinning is not particularly limited, and a nozzle corresponding to the desired fiber cross-section can be used as appropriate. For example, by using a nozzle with an anchor Y-shaped cross-section, an acrylic fiber with an anchor Y-shaped cross-section can be obtained. Figure 7 shows a schematic cross-sectional view of one example of a nozzle with an anchor Y-shaped cross-section. In this spinning nozzle, although not particularly limited, for example, the shaft width Aw may be 0.02 mm or more and 1.0 mm or less, the canal width Cw may be 0.02 mm or more and 1.0 mm or less, the circumscribed circle diameter Cd may be 0.01 mm or more and 1.0 mm or less, and the pore area may be 0.05 mm². 2 1.0mm or more 2 The following is also acceptable.

[0047] Furthermore, by using a nozzle with a C-shaped cross-section, acrylic fibers having a C-shaped or six-shaped cross-section can be obtained.

[0048] Figure 8 shows a schematic cross-sectional view of a nozzle (hereinafter also referred to as an I-type spinning nozzle) having a C-shaped cross-section with two ends separated from each other, where each end has a straight section and an outwardly bulging projection, and the straight sections of the two ends are parallel to each other. In the cross-section of the I-type spinning nozzle, the two ends of the C-shape have straight sections 11a and 11b and projections 12a and 12b, respectively, with the straight sections 11a and 11b being parallel to each other. The straight sections and projections can be adjusted as appropriate depending on the desired fiber cross-sectional shape and size. In the I-type spinning nozzle, the circumscribed circle diameter Cd may be 0.37 mm or more and 0.60 mm or less, the canal width Cw may be 0.06 mm or more and 0.24 mm or less, the slit width Aw may be 0.06 mm or more and 0.15 mm or less, and the pore area is 0.0850 mm². 2 More than 0.1256mm 2 The following is also acceptable.

[0049] Figure 9 shows a schematic cross-sectional view of a nozzle (hereinafter also referred to as a Type II spinning nozzle) having a C-shaped cross-section, where one end of the C-shape is located inward from the other end. In the Type II spinning nozzle, one end 13a of the C-shape is located inward from the other end 13b. The degree of displacement between the two ends can be adjusted as appropriate depending on the desired fiber cross-sectional shape and size. In the cross-section of the Type II spinning nozzle, the circumscribed circle diameter Cd may be between 0.37 mm and 0.60 mm, the canal width Cw may be between 0.06 mm and 0.24 mm, the slit width Aw may be between 0.06 mm and 0.15 mm, and the pore area may be 0.0850 mm². 2 More than 0.1256mm 2 The following is also acceptable.

[0050] The spinning speed is not particularly limited, but from the viewpoint of industrial productivity, for example, it is preferably 2 m / min to 17 m / min. The nozzle draft is not particularly limited, but from the viewpoint of manufacturing process stability, for example, it is preferably 0.8 to 2.0. By appropriately adjusting the cross-sectional shape and size of the spinning nozzle, spinning conditions such as spinning speed and nozzle draft, and the draw ratio described later, acrylic fibers having a predetermined cross-sectional shape and size can be obtained.

[0051] The coagulation bath can be an aqueous solution of a good solvent, such as dimethyl sulfoxide, with a concentration of 20% to 70% by weight. The temperature of the coagulation bath can be between 5°C and 40°C. If the organic solvent concentration in the coagulation bath is too low, coagulation will proceed too quickly, resulting in a coarse coagulation structure and a tendency to form voids inside the fibers.

[0052] Next, in the primary drawing process (also referred to as the bath drawing process), the coagulated yarn is wet-drawn to obtain primary-drawn yarn. In the bath drawing process, it is preferable that the acrylic fibers (coagulated yarn) are drawn in a drawing bath. The drawing bath can be an aqueous solution with a lower concentration of a good solvent such as dimethyl sulfoxide than the coagulation bath. From the viewpoint of spinning stability, the temperature of the wet drawing, specifically the temperature of the drawing bath, is preferably 30°C to 100°C, more preferably 40°C to 95°C, and even more preferably 50°C to 93°C. The drawing ratio is not particularly limited, but from the viewpoint of increasing fiber strength and productivity, it is preferably 2 to 8 times. When primary drawing is performed using a water bath, the bath drawing process may be performed after the water washing process described later, or primary drawing and water washing may be performed simultaneously.

[0053] Next, in the washing process, it is desirable to remove organic solvents such as acetone from the acrylic fibers by washing them with hot water at 30°C or higher. Alternatively, the coagulated yarn may be introduced into hot water at 30°C or higher, and primary drawing and washing may be performed simultaneously. In the washing process, for example, using hot water at 70°C or higher makes it easier to remove good solvents such as acetone from the acrylic fibers. From the viewpoint of spinning stability, it is desirable that the upper limit of the water temperature during washing be 95°C or lower.

[0054] Next, the primary drawn yarn is dried and then secondary drawing is performed. That is, secondary drawing is dry drawing. The drying temperature is not particularly limited, but for example, it is 110°C to 190°C. The drawing temperature for secondary drawing is not particularly limited, but for example, from the viewpoint of spinning stability, it is preferably 110°C to 190°C, similar to the drying temperature. The draw ratio is not particularly limited, but for example, it is preferably 1 to 4 times, more preferably 1 to 3 times, and even more preferably 1 to 2 times. The total draw ratio, which is the sum of the draw ratios for primary and secondary drawing, is preferably 2 to 10 times, more preferably 2 to 8 times, even more preferably 2 to 6 times, and particularly preferably 2 to 4 times.

[0055] Before the drying process, an oil solution may be used to apply an oil, if necessary. The oil solution may also contain other additives to improve fiber properties, as necessary, as long as they do not hinder the effects of the present invention. Examples of additives include fiber binding agents.

[0056] (Acrylic crimped fibers for artificial hair and method for manufacturing the same) The inventors of the present invention have found that in an acrylic crimped fiber for artificial hair composed of an acrylic copolymer, having 10 or more crimps per 10 cm, a crimp height of 1.5 mm or more, and having at least two crimps of different widths, at least two crimps of different heights, and two or more different crimp directions, i.e., having an irregular crimp, results in a good feel, high volume, and good compatibility between the crimps and natural hair. Figure 11 schematically shows the appearance of an acrylic crimped fiber for artificial hair having an irregular crimp, i.e., at least two crimps of different widths, at least two crimps of different heights, and two or more different crimp directions.

[0057] The crimp count of acrylic crimped fibers for artificial hair is preferably 11 crimps / 10cm or more, and more preferably 12 crimps / 10cm or more, from the viewpoint of further enhancing volume and the blending of the crimps with natural hair. There is no particular upper limit to the crimp count of acrylic crimped fibers for artificial hair, but for example, from the viewpoint of tactile feel, it is preferably 30 crimps / 10cm or less, more preferably 25 crimps / 10cm or less, and even more preferably 20 crimps / 10cm or less. Specifically, the crimp count of acrylic crimped fibers for artificial hair is preferably 10 crimps / 10cm or more and 30 crimps / 10cm or less, more preferably 11 crimps / 10cm or more and 25 crimps / 10cm or less, and even more preferably 12 crimps / 10cm or more and 20 crimps / 10cm or less.

[0058] In this specification, the crimp count of acrylic crimped fibers for artificial hair refers to the average number of crimps generated per 10 cm of fiber length when five acrylic crimped fibers for artificial hair are arbitrarily selected and both ends of each fiber (fiber length 20 cm) are fixed to A4 size graph paper. In this specification, a crimp refers to the crimped portion consisting of two contact points where the fiber touches the graph paper and the portion of the fiber between these two contact points that does not touch the graph paper, and a single crimp may have two or more peaks.

[0059] In acrylic crimped fibers for artificial hair, the average crimp height per 10 cm of fiber is preferably 1.6 mm or more, more preferably 1.7 mm or more, even more preferably 1.8 mm or more, and particularly preferably 1.9 mm or more, from the viewpoint of further enhancing volume and the blending of the crimp with natural hair. In acrylic crimped fibers for artificial hair, there is no particular upper limit to the average crimp height per 10 cm of fiber, but from the viewpoint of tactile feel, it is preferably 3.0 mm or less, more preferably 2.9 mm or less, even more preferably 2.8 mm or less, even more preferably 2.7 mm or less, and even more preferably 2.5 mm or less. Specifically, in acrylic crimped fibers for artificial hair, the average crimp height per 10 cm of fiber is preferably 1.5 mm or more and 3.0 mm or less, 1.6 mm or more and 2.9 mm or less, 1.7 mm or more and 2.8 mm or less, 1.8 mm or more and 2.7 mm or less, or 1.9 mm or more and 2.5 mm or less.

[0060] In acrylic crimped fibers for artificial hair, the average crimp height per 10 cm of fiber is calculated by arbitrarily selecting five acrylic crimped fibers for artificial hair, fixing both ends of each fiber (20 cm in length) to A4 size graph paper, measuring the height of all crimp peaks (crimp height) occurring within a 10 cm length of the fiber, and averaging these values. In this specification, if a single crimp has two or more peaks, the crimp height refers to the height of the highest peak.

[0061] The volume of the acrylic crimped fibers for artificial hair is preferably 25 mm or more, more preferably 26 mm or more, even more preferably 27 mm or more, and particularly preferably 28 mm or more. The upper limit of the volume of the acrylic crimped fibers for artificial hair is not particularly limited, but for example, from the viewpoint of a natural appearance, it is preferably 50 mm or less, more preferably 48 mm or less, even more preferably 47 mm or less, and even more preferably 45 mm or less. Specifically, the volume of the acrylic crimped fibers for artificial hair is preferably 25 mm or more and 50 mm or less, 26 mm or more and 48 mm or less, 27 mm or more and 47 mm or less, or 28 mm or more and 45 mm or less.

[0062] In this specification, the volume of acrylic crimped fibers for artificial hair can be measured as follows. (1) Acrylic crimped fibers for artificial hair are processed into a 38-inch (approximately 96.5 cm, approximately 50 g) fiber bundle, the center is secured with rubber, and the bundle is folded back starting from the center. The resulting folded fiber bundle is used as the sample. (2) The sample is placed on the support stand of the bulk measuring instrument (12 cm long x 1.6 cm wide x 10 cm high) so that the fiber length direction coincides with the length direction of the bulk measuring instrument. A rectangular weight (17 cm long x 1.5 cm wide x 0.5 cm high, 20 g) is placed on the sample parallel to the fiber length direction of the sample and the length direction of the weight coincides with the fiber length direction of the sample. The bulk (height) of the sample at the location where the weight is placed is measured, and the volume is determined.

[0063] Acrylic crimped fibers for artificial hair preferably have the same torsional rigidity, fiber cross-sectional shape and size, fineness, and void ratio as described above for acrylic fibers for artificial hair. The above information described for acrylic fibers for artificial hair can be directly applied, and a detailed explanation of the torsional rigidity, fiber cross-sectional shape and size, fineness, and void ratio of acrylic crimped fibers for artificial hair is omitted.

[0064] Furthermore, acrylic crimped fibers for artificial hair can be composed of the same acrylic copolymer as described above for acrylic fibers for artificial hair. The information described above for acrylic fibers for artificial hair can be directly applied, and a detailed explanation of the acrylic copolymer that constitutes the acrylic crimped fibers for artificial hair will be omitted.

[0065] The acrylic crimped fibers for artificial hair are preferably those in which the above-mentioned acrylic fibers for artificial hair are irregularly crimped. That is, the acrylic crimped fibers for artificial hair can be produced by imparting irregular crimping to the above-mentioned acrylic fibers for artificial hair.

[0066] The crimp is not limited to irregular crimp, but it is preferable that the irregular crimp is imparted by heat shrinking the aforementioned acrylic fibers for artificial hair in a tension-free state (i.e., a free state). By having irregular crimp due to heat shrinkage in the acrylic crimped fibers for artificial hair, it is possible to obtain acrylic crimped fibers for artificial hair that have sufficient volume when worn by small children and have a crimp that blends well with natural hair.

[0067] When the crimping process is performed by heat shrinkage, the temperature and time of the heat treatment are not particularly limited. However, from the viewpoint of obtaining acrylic crimped fibers for artificial hair that have sufficient volume and a crimp that blends well with natural hair, even when worn by small children, the temperature is preferably 90°C to 150°C, more preferably 100°C to 140°C, and even more preferably 105°C to 135°C. The time is preferably 5 minutes to 60 minutes, more preferably 10 minutes to 50 minutes, and even more preferably 15 minutes to 40 minutes.

[0068] Besides thermal shrinkage of fibers, another processing method for imparting crimp is the gear crimp method. However, the gear crimp method imparts fine crimps to the fibers at regular intervals, which tends to result in a more regular pattern. While it is possible to combine thermal shrinkage of fibers with the gear crimp method to impart crimp, thermal shrinkage of fibers alone is preferable.

[0069] The method for producing acrylic crimped fibers for artificial hair more specifically preferably includes a coagulation step of wet spinning a spinning solution containing an acrylic copolymer using a spinning nozzle to obtain a coagulated yarn, a primary drawing step of wet drawing the obtained coagulated yarn, a secondary drawing step of dry drawing the obtained primary drawn yarn, and a step of heat shrinking the obtained secondary drawn yarn at a temperature of 90°C to 150°C for 5 to 60 minutes to impart crimp. The coagulation step, primary drawing step, and secondary drawing step can be carried out in the same manner as described in the method for producing acrylic fibers for artificial hair, and will not be described here.

[0070] (headdress products) The acrylic fibers and / or crimped acrylic fibers described above can be used as artificial hair to construct headwear products. In addition to the acrylic fibers and / or crimped acrylic fibers described above, headwear products may also contain other artificial hairs or natural fibers such as human hair and animal hair as appropriate. Other artificial hairs are not particularly limited, but examples include polyvinyl chloride fibers, nylon fibers, polyester fibers, and regenerated collagen fibers.

[0071] Examples of headwear products include hair fiber bundles, weaving, wigs, braids, toupees, hair extensions, and hair accessories, with braids being particularly preferred. [Examples]

[0072] One or more embodiments of the present invention will be specifically described below in the examples, but the present invention is not limited to the following embodiments.

[0073] (Example 1) <Manufacturing of acrylic fibers> An acrylic copolymer consisting of 49% by mass of acrylonitrile, 50% by mass of vinyl chloride, and 1% by mass of sodium styrene sulfonate was dissolved in acetone to prepare a spinning solution with a resin concentration of 29.5% by mass. This spinning solution was extruded into a coagulation bath consisting of a 25% by mass aqueous acetone solution at 25°C using an anchor-shaped Y-shaped spinning nozzle having the cross-sectional shape shown in Figure 7 and the cross-sectional size shown in Table 1, and wet spinning was performed at a spinning speed of 3 m / min and a nozzle draft of 1.17. The obtained fibers were stretched 1.6 times in a stretching bath of a 20% by mass aqueous acetone solution at 50°C. The obtained stretched fibers were washed with hot water at 80°C, then dried at 130°C, and stretched 1.9 times to obtain acrylic fibers. <Manufacturing of acrylic crimped fibers> The obtained acrylic fibers were heat-shrinked at 120°C for 30 minutes in a tension-free state to impart irregular crimp, thereby obtaining crimped acrylic fibers.

[0074] (Example 2) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Example 1, except that a C-shaped nozzle having the cross-sectional shape shown in Figure 9 and the cross-sectional size shown in Table 1 was used.

[0075] (Example 3) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Example 1, except that a C-shaped nozzle having the cross-sectional shape shown in Figure 9 and the cross-sectional size shown in Table 1 was used.

[0076] (Comparative Example 1) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Example 1, except that a dumbbell-shaped nozzle, as shown in Figure 10, was used.

[0077] (Comparative Example 2) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Comparative Example 1, except that after stretching at 130°C, relaxation with a relaxation rate of 10% was performed at 150°C.

[0078] (Comparative Example 3) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Example 1, except that after stretching at 130°C, relaxation was performed at 150°C with a relaxation rate of 10%.

[0079] (Comparative Example 4) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Example 2, except that after stretching at 130°C, relaxation with a relaxation rate of 10% was performed at 150°C.

[0080] (Comparative Example 5) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Example 3, except that after stretching at 130°C, relaxation was performed at 150°C with a relaxation rate of 10%.

[0081] (Comparative Example 6) Acrylic fibers and crimped acrylic fibers were obtained in the same manner as in Example 1, except that a round nozzle was used and a 10% relaxation was performed at 150°C after stretching at 130°C.

[0082] [Table 1]

[0083] The single fiber fineness, dry heat shrinkage rate, and torsional stiffness of the acrylic fibers in the examples and comparative examples were measured as follows. The volume, crimp number, and crimp height of the crimped acrylic fibers in the examples and comparative examples were measured as follows. The results are shown in Table 2.

[0084] (Single fiber fineness) Acrylic fibers were measured using an autobibro type fiber densitometer (DENICON DC-21A, Search Co., Ltd.) to measure the density of a single fiber over a length of 50 mm. The average value of 20 densities was then defined as the single fiber density.

[0085] (Dry heat shrinkage rate) Using acrylic fibers, fiber bundles were prepared with a total fineness of 3333 dtex. Under a load of 50 g, the fiber length (effective sample length) was marked with cotton yarn to 200 mm to prepare the sample for measurement. The sample was heat-treated in a uniform heat dryer at 120°C for 30 minutes under tension-free conditions. After removing the sample and cooling it to room temperature, the fiber length (effective sample length) LD (mm) of the sample under a load of 50 g was measured, and the dry heat shrinkage rate was calculated using the following formula 1. [Formula 1] Dry heat shrinkage rate (%)=100×(200-LD) / 200

[0086] (Torsostability) A 3cm long acrylic fiber (single yarn) was placed in a torsion testing machine (KES-YN1, Kato Tech Co., Ltd.), and its torsional stiffness was measured under the conditions of a twisting rotation of ±3 turns and a twisting speed of 12° / second. The average of 5 measurements was used to determine the torsional stiffness value (unit: mg·cm). 2 ) was calculated as follows.

[0087] (volume) (1) Acrylic fibers were processed into a 38-inch (approximately 96.5 cm, approximately 50 g) fiber bundle, the longitudinal center of the fiber bundle was secured with rubber, and the bundle was folded back starting from the center, and the resulting folded fiber bundle was used as a sample. (2) The sample was suspended inside a dryer and heated at 120°C for 30 minutes in an unloaded (free) state to cause it to crimp. (3) The sample was placed on the support stand of the bulk measuring instrument (12 cm long x 1.6 cm wide x 10 cm high) so that the fiber length direction was aligned with the length direction of the bulk measuring instrument. A rectangular weight (17 cm long x 1.5 cm wide x 0.5 cm high, 20 g) was placed on the sample parallel to the fiber length direction of the sample and the length direction of the weight, and the volume was determined by measuring the height of the crimped sample at the location where the weight was placed. A volume of 25 mm or more indicates that the volume is acceptable.

[0088] (Crimp count) Five acrylic crimped fibers were randomly selected, and both ends of each fiber (20 cm in length) were fixed to A4 size graph paper. The number of crimps occurring within a 10 cm length of the fiber was measured, and the crimp count was calculated by averaging these numbers. A crimp count of 10 or more per 10 cm indicates that the fiber is satisfactory in terms of blending with natural hair. Here, "crimp" refers to the crimped portion consisting of two contact points where the fibers and the graph paper are in contact, and the portion of the fibers between these two contact points that is not in contact with the graph paper. A single crimp may have two or more ridges.

[0089] (Average crimp height) Five acrylic crimped fibers were randomly selected, and both ends of each fiber (20 cm in length) were fixed to A4-sized graph paper. The height of each crimp within a 10 cm length of the fiber was measured. The average crimp height per 10 cm of fiber was then calculated by averaging these measurements. An average crimp height of 1.5 mm or more per 10 cm of fiber indicates that the fiber is acceptable in terms of blending with natural hair. As described above, a crimp refers to the crimped portion consisting of two points of contact between the fibers and the graph paper, and the portion of the fibers between these two points of contact that is not in contact with the graph paper. If a single crimp has two or more ridges, the crimp height refers to the height of the highest ridge. For example, as shown in Figure 12, crimp 101 refers to the crimped portion consisting of contact points 111 and 112 where the fiber 110 is in contact with the graph paper (not shown), and the portion of the fiber 120 between contact points 111 and 112 that is not in contact with the graph paper. Crimp 102 refers to the crimped portion consisting of contact points 112 and 113 where the fiber 110 is in contact with the graph paper, and the portion of the fiber 130 between contact points 112 and 113 that is not in contact with the graph paper. The crimp heights of crimp 101 and crimp 102 are indicated by h1 and h2, respectively.

[0090] (Crim width) Five acrylic crimped fibers were arbitrarily selected, and both ends of each fiber (20 cm in length) were fixed to A4 size graph paper. The width of each crimp that occurred within a 10 cm length of the fiber was then measured. As described above, a crimp refers to the crimped portion consisting of two contact points where the fibers and the graph paper are in contact, and the portion of the fibers between these two contact points that is not in contact with the graph paper. The crimp width refers to the distance between the two contact points where the fibers and the graph paper are in contact. For example, in Figure 12, the crimp widths of crimp 101 and crimp 102 are shown as w1 and w2, respectively.

[0091] (Crimp direction) Five acrylic crimped fibers were arbitrarily selected, and both ends of each fiber (20 cm in length) were fixed to A4 size graph paper. The direction facing the graph paper and along the fiber axis was defined as the X-axis, the direction facing the graph paper and perpendicular to the fiber axis as the Y-axis, and the direction perpendicular to the graph paper as the Z-axis. The crimp direction was then determined by evaluating whether adjacent crimps corresponded to the X-Y axis direction, XZ axis direction, Y-Z axis direction, or XYZ axis direction.

[0092] (Method for evaluating irregular crimping) Based on the results regarding crimp height, crimp width, and crimp direction described above, it was determined that irregular crimping was present if, among 10 consecutive crimps, at least two crimps had different crimp widths, at least two crimps had different crimp heights, and there were two or more different crimp directions.

[0093] (Evaluation of tactile sensation) The tactile feel of acrylic crimped fibers was evaluated using the following criteria. A score of 3 or higher indicates that the tactile feel is satisfactory. <Evaluation Criteria> 5: Very soft 4: Soft 3: Slightly soft 2: Somewhat hard 1: Hard

[0094] (comprehensive evaluation) Acrylic crimped fibers were comprehensively evaluated according to the following evaluation criteria. Good: All evaluation criteria, including volume, crimp count, average crimp height, irregular crimping, and tactile feel, are satisfactory. Defective: If any one of the following evaluation criteria fails, it will be volume, crimp count, average crimp height, irregular crimping, or tactile feel.

[0095] (Cross-sectional evaluation) <Sample preparation> An appropriate amount of acrylic fiber or crimped acrylic fiber, cut to a length of 15 cm, was packed into a heat-shrinkable tube (Junkou Co., Ltd., model number "FEP-040", inner diameter before shrinkage φ4.5 mm, inner diameter after shrinkage φ3.3 mm, length 1 m) and left in a 105°C oven for 5 minutes. After removal and cooling, the heat-shrinkable tube filled with acrylic fiber or crimped acrylic fiber was cut to a length of approximately 3 mm using a razor to prepare a sample for observing the fiber cross-section. <Observation and Photography> Samples for observing fiber cross-sections were observed and photographed using a laser microscope (VK-X260, KEYENCE) with an observation measurement range of 675 μm horizontally and 506 μm vertically. Observation and photography were performed at a total of 5 locations. Figures 13 to 17 show cross-sectional images of acrylic crimped fibers from Examples 1 to 3 and Comparative Examples 1 and 6, respectively. (Method for analyzing cross-sectional images) Cross-sectional images were imported into image analysis software (WinROOF, Mitsubishi Corporation), and the area of ​​the circumscribed circle and the area of ​​the fiber cross-section were calculated. The void ratio was then determined using Equation 2 below. The area of ​​the circumscribed circle of the fiber cross-section is the area of ​​the circle whose diameter is the longest line segment formed by connecting any two points on the outer circumference of the fiber cross-section. [Formula 2] Porosity (%) = 100 × (Area of ​​the circumscribed circle of the fiber cross-section - Area of ​​the fiber cross-section) / Area of ​​the circumscribed circle of the fiber cross-section

[0096] [Table 2]

[0097] As can be seen from the data in Table 2, the acrylic fibers in the examples exhibited a good tactile feel, high volume, and a crimp that blended well with natural hair, even when irregular crimping was applied.

[0098] On the other hand, the torsional rigidity is 2.0 mg / cm². 2 Comparative Example 1, exceeding the above, had a torsional rigidity of 2.0 mg / cm². 2 The acrylic fibers of Comparative Example 2, which exceeded the limit and had a dry heat shrinkage rate of less than 30%, and the acrylic fibers of Comparative Examples 3 to 6, which also had a dry heat shrinkage rate of less than 30%, had a good feel when irregular crimping was applied, but they had low volume and poor blending with natural hair.

[0099] The present invention is not particularly limited, but includes at least the following embodiments. [1] Acrylic fiber for artificial hair composed of an acrylic copolymer, The dry heat shrinkage rate when dry heat treatment is performed at a temperature of 90°C to 180°C for 30 minutes is 30% to 70%, and, Torsional rigidity is 0.3 mg·cm 2 More than 2.0 mg cm 2 The following are acrylic fibers for artificial hair. [2] An acrylic fiber for artificial hair according to [1], having one or more cross-sectional shapes selected from the group consisting of anchor Y-shape, C-shape, and hexagonal shape. [3] Acrylic fiber for artificial hair as described in [1] or [2], wherein the single fiber fineness is 25 dtex or more and 95 dtex or less. [4] An acrylic fiber for artificial hair as described in any of [1] to [3], wherein the void ratio of the fiber cross-section is 20% or more and 50% or less. [5] Acrylic crimped fiber for artificial hair composed of an acrylic copolymer, The number of crimps is 10 or more per 10 cm. The average crimp height per 10 cm of fiber is 1.5 mm or more. An acrylic crimped fiber for artificial hair, comprising 10 consecutive crimps, wherein at least two crimps have different crimp widths, at least two crimps have different crimp heights, and the crimps have two or more different crimp directions. [6] An acrylic crimped fiber for artificial hair according to [5], having one or more cross-sectional shapes selected from the group consisting of anchor Y-shape, C-shape, and hexagonal shape. [7] An acrylic crimped fiber for artificial hair according to [5] or [6], wherein the single fiber fineness is 25 dtex or more and 95 dtex or less. [8] An acrylic crimped fiber for artificial hair according to any of [5] to [7], wherein the void ratio of the fiber cross-section is 20% or more and 50% or less. A head accessory product containing an acrylic fiber for artificial hair as described in any of [9] [1] to [4], or an acrylic crimped fiber for artificial hair as described in any of [5] to [8].

[10] The headwear product according to [9], wherein the headwear product is at least one selected from the group consisting of hair fiber bundles, weaving, wigs, braids, toupees, hair extensions and hair accessories. A method for producing acrylic fibers for artificial hair as described in any of [1] to [4], A coagulation step in which a spinning solution containing an acrylic copolymer is wet-spun using a spinning nozzle to obtain coagulated yarn. A primary stretching step in which the obtained coagulated yarn is wet-stretched, and The process includes a secondary drawing step in which the obtained primary drawn yarn is dry-drawn. A method for manufacturing acrylic fibers for artificial hair, which does not involve a relaxation treatment after the secondary drawing process. A method for producing acrylic crimped fibers for artificial hair as described in any of

[12] [5] to [8], A coagulation step in which a spinning solution containing an acrylic copolymer is wet-spun using a spinning nozzle to obtain coagulated yarn. The obtained coagulated yarn is subjected to a primary stretching process using a wet stretching method. A secondary drawing process in which the obtained primary drawn yarn is dry-drawn, and A method for producing acrylic crimped fibers for artificial hair, comprising the step of heat-shrinking the obtained secondary drawn yarn at a temperature of 90°C to 150°C for 5 minutes to 60 minutes in a tension-free state to impart crimp. [Explanation of Symbols]

[0100] 1. Acrylic fibers for artificial hair 2 Center 3 T-shaped projection 4 Top edge 5 Lower protrusion 11a, 11b Straight section 12a, 12b protrusion 13a, 13b ends 101, 102 Crimp 110 Fibers 111, 112, 113 contacts 120, 130 The fibrous portion between the two contact points

Claims

1. Acrylic fiber for artificial hair, composed of an acrylic copolymer, Having one or more cross-sectional shapes selected from the group consisting of anchor Y-shape, C-shape, and six-shape, The dry heat shrinkage rate when dry heat treatment is performed at a temperature of 90°C to 180°C for 30 minutes is 30% to 70%, and, Torsional rigidity is 0.3 mg·cm 2 2.0mg・cm or more 2 The following are acrylic fibers for artificial hair.

2. The acrylic fiber for artificial hair according to claim 1, wherein the single fiber fineness is 25 dtex or more and 95 dtex or less.

3. The acrylic fiber for artificial hair according to claim 1, wherein the void ratio of the fiber cross-section is 20% or more and 50% or less.

4. A head accessory product comprising acrylic fibers for artificial hair as described in any one of claims 1 to 3.

5. The head ornament product according to claim 4, wherein the head ornament product is at least one selected from the group consisting of hair fiber bundles, weaving, wigs, braids, toupees, hair extensions, and hair accessories.

6. A method for producing acrylic fibers for artificial hair according to any one of claims 1 to 3, A coagulation step in which a spinning solution containing an acrylic copolymer is wet-spun using a spinning nozzle to obtain coagulated yarn. A primary stretching step in which the obtained coagulated yarn is wet-stretched, and The process includes a secondary stretching step in which the obtained primary stretched yarn is dry stretched. A method for manufacturing acrylic fibers for artificial hair, which does not involve a relaxation treatment after the secondary drawing process.

Images