Core-sheath composite fiber for artificial hair, head accessories containing the same, and manufacturing method thereof

Abstract

One or more embodiments of the present invention relate to a core-sheath composite fiber for artificial hair comprising a core part and a sheath part, wherein: the core part is constituted by a polyester resin composition in which a polyester resin is the main component; the sheath part is constituted by a polyamide resin composition which contains a polyamide resin as the main component; the sheath part contains at least one organic pigment selected from the group consisting of (a) nickel complex pigments in which nickel and an organic dye structure are in a coordinate bond at the ratio of 1:1 or 1:2, (b) chromium complex pigments in which chromium and an organic dye structure are in a coordinate bond at the ratio of 1:1 or 1:2, and (c) organic pigments which contain a nitro group but do not contain metal; and the core part contains a pigment differing from that of the sheath part. Thus, provided are a core-sheath composite fiber for artificial hair which has a texture similar to that of human hair and which exhibits good color formation and spinning properties, a headwear product including the same, and a production method for the same.

Description

[Technical Field]

[0001] The present invention relates to a core-sheath composite fiber for artificial hair that can be used as a substitute for human hair, a head accessory containing the same, and a method for producing the same. [Background technology]

[0002] Human hair has traditionally been used in head accessories such as wigs, hairpieces, hair extensions, hair bands, and doll hair. However, in recent years, it has become difficult to obtain human hair, and there has been an increasing demand for artificial hair as an alternative to human hair.

[0003] Synthetic fibers used as materials for artificial hair include acrylic fibers, vinyl chloride fibers, vinylidene chloride fibers, polyester fibers, polyamide fibers, polyolefin fibers, etc. For example, Patent Document 1 proposes a core-sheath composite fiber, which has a polyester core component and a polyamide sheath component, as a fiber for artificial hair. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 187843 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although fibers with a polyamide sheath component such as those described in Patent Document 1 have a texture similar to that of human hair, when they are subjected to a dyeing process using a pigment, the refractive indexes of the core and sheath components are different, which causes refraction at the interface between the components, making it difficult to obtain the intended hue.

[0006] In order to solve the above problems, the present invention provides a core-sheath composite fiber for artificial hair that has a texture similar to that of human hair and has good color development and spinnability, a head accessory product containing the same, and a method for producing the same. [Means for solving the problem]

[0007] In one or more embodiments, the present invention relates to a sheath-core composite fiber for artificial hair, comprising a core and a sheath, wherein the core is made of a polyester-based resin composition containing a polyester-based resin, the sheath is made of a polyamide-based resin composition containing a polyamide-based resin, the sheath contains one or more organic pigments selected from the group consisting of (a) a nickel complex pigment in which nickel and an organic dye structure are coordinately bonded in a 1:1 or 1:2 ratio, (b) a chromium complex pigment in which chromium and an organic dye structure are coordinately bonded in a 1:1 or 1:2 ratio, and (c) a metal-free organic pigment containing a nitro group, and the core contains a pigment different from that of the sheath.

[0008] In one or more embodiments, the present invention also relates to a head accessory comprising the core-sheath composite fiber for artificial hair.

[0009] In one or more embodiments, the present invention also relates to a method for producing the sheath-core composite fiber for artificial hair, the method comprising the steps of: mixing one or more sheath pigments selected from the group consisting of (a) a nickel complex pigment in which nickel and an organic dye structure are coordinated in a 1:1 or 1:2 ratio, (b) a chromium complex pigment in which chromium and an organic dye structure are coordinated in a 1:1 or 1:2 ratio, and (c) a metal-free organic pigment containing a nitro group, with a polyamide resin to prepare a sheath pigment masterbatch; mixing a pigment different from the sheath pigment with a polyester resin to prepare a core pigment masterbatch; and melt-spinning the core resin composition and the sheath resin composition using a core-sheath composite nozzle. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a core-sheath composite fiber for artificial hair, which has a texture similar to that of human hair and has good color development and spinnability, and a head ornament product.

[0011] According to the production method of the present invention, it is possible to obtain, with good spinnability, core-sheath composite fibers for artificial hair that have a texture similar to that of human hair and good color development. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing the cross section of a core-sheath composite fiber for artificial hair according to one or more embodiments of the present invention. [Figure 2] FIG. 2 is a laser microscope photograph of the cross section of the core-sheath composite fiber for artificial hair of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] The inventors of the present invention have conducted extensive research to solve the problems of the prior art described above, and as a result, have found that in a sheath-core composite fiber for artificial hair, the core of which is composed of a polyester-based resin composition containing a polyester-based resin as a main component and the sheath of which is composed of a polyamide-based resin composition containing a polyamide-based resin as a main component, the sheath contains one or more pigments selected from the group consisting of (a) a nickel complex pigment in which nickel and an organic dye structure are coordinated in a 1:1 or 1:2 ratio (hereinafter also referred to as nickel complex pigment (a)), (b) a chromium complex pigment in which chromium and an organic dye structure are coordinated in a 1:1 or 1:2 ratio (hereinafter also referred to as chromium complex pigment (b)), and (c) a metal-free organic pigment containing a nitro group (hereinafter also referred to as nitro group-containing organic pigment (c)), and the core contains a pigment different from that of the sheath, a sheath-core composite fiber for artificial hair with a texture similar to that of human hair and good colorability and spinnability can be obtained.

[0014] (Pigment for sheath) The sheath contains one or more organic pigments selected from the group consisting of nickel complex pigments (a), chromium complex pigments (b), and nitro group-containing organic pigments (c).

[0015] <Nickel complex pigment (a)> The nickel complex pigment (a) is a metal complex pigment in which nickel and an organic dye structure are coordinated with each other in a ratio of 1:1 or 1:2.

[0016] In the nickel complex pigment (a), examples of the organic dye structure include azo-based, azomethine-based, and phthalocyanine-based structures. Among these, from the viewpoint of easy dispersion in polyamide-based resins, the organic dye structure is preferably one or more selected from the group consisting of azo-based and azomethine-based structures.

[0017] The nickel complex pigment (a) may contain one or more functional groups selected from the group consisting of a sulfone group, a sulfonamide group, and a nitro group.

[0018] Specifically, the nickel complex pigment (a) may be an azomethine-based nickel complex pigment represented by the following chemical formula (1).

[0019] [ka]

[0020] In chemical formula (1), R 1 ~R 4 are each independently a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a sulfone group. Examples of the hydrocarbon group having 1 to 5 carbon atoms include a methyl group and an ethyl group.

[0021] As the azomethine-based nickel complex pigment represented by chemical formula (1), for example, Pigment Yellow 150 (CAS number: 68511-62-6) can be suitably used.

[0022] Pigment Yellow 150 is a 5,5'-azodi(2,4,6-pyrimidinetriol) 1:1 type nickel(II) complex salt and has the structure shown in the following chemical formula (2).

[0023] [ka]

[0024] <Chromium complex pigment (b)> The chromium complex pigment (b) is a metal complex pigment in which chromium and an organic dye structure are coordinated in a 1:1 or 1:2 ratio.

[0025] In the chromium complex pigment (b), examples of the organic dye structure include azo-based, azomethine-based, and phthalocyanine-based structures. Among these, from the viewpoint of easy dispersion in polyamide-based resins, the organic dye structure is preferably one or more selected from the group consisting of azo-based and azomethine-based structures.

[0026] The chromium complex pigment (b) may contain one or more functional groups selected from the group consisting of a sulfone group, a sulfonamide group, and a nitro group.

[0027] As the chromium complex pigment (b), azo-based chromium complex pigments represented by the following chemical formula (3) or (4) can be suitably used.

[0028] [ka]

[0029] [ka]

[0030] The azo chromium complex pigment (CAS No.: 10127-27-2) represented by the above chemical formula (3) is 3-[[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl]azo]-2-hydroxy-5-nitrobenzenesulfonic acid / sodium / chromic acid (1:1:1), which contains a nitro group and a sulfonic acid group. It is also known as Acid Orange 74.

[0031] The azo chromium complex pigment (CAS number: 84179-66-8) represented by the above chemical formula (4) is bis[3-hydroxy-4-[(2-hydroxy-3,5-dinitrophenyl)azo]-N-phenyl-2-naphthalenecarboxamide(2-)]hydrogenchromate, which contains a nitro group.

[0032] <Nitro group-containing organic pigment (c)> As the nitro group-containing organic pigment (c), a metal-free organic pigment containing a nitro group can be used as appropriate. Examples of the nitro group-containing organic pigment (c) include nitro group-containing azo organic pigments, nitro group-containing azomethine organic pigments, nitro group-containing azobenzene organic pigments, and nitro group-containing hydrazine organic pigments. Among these, from the viewpoint of easy dispersion in polyamide resins, the nitro group-containing organic pigment (c) is preferably one or more selected from the group consisting of nitro group-containing azo organic pigments, nitro group-containing azomethine organic pigments, and nitro group-containing azobenzene organic pigments.

[0033] As the nitro group-containing organic pigment (c), specifically, a nitro group-containing azo organic pigment represented by the following chemical formula (5) can be used.

[0034] [ka]

[0035] The nitro group-containing azo organic pigment (CAS number: 2512-29-0) represented by the above chemical formula (5) is N-phenyl-2-(4-methyl-2-nitrophenylazo)-3-oxobutanamide, and is also known as Hansa Yellow.

[0036] The pigments for the sheath may be used alone or in combination of two or more.

[0037] (Core pigment) For the core, a pigment different from the above-mentioned pigment for the sheath can be used as appropriate. The pigment for the core is not particularly limited, and for example, inorganic pigments or organic pigments can be used. Examples of inorganic pigments include carbon black and titanium oxide. Examples of organic pigments include anthraquinone-based pigments and perylene-based pigments.

[0038] Specifically, the pigment for the core may be an anthraquinone pigment represented by the following chemical formula (6) or a perylene pigment represented by the following chemical formula (7).

[0039] [ka]

[0040] [ka]

[0041] The anthraquinone pigment (CAS number: 4118-16-5) represented by the above chemical formula (6) is 1,1′-[(6-phenyl-1,3,5-triazine-2,4-diyl)bis(imino)]bis(9,10-anthracenedione) and is called Pigment Yellow 147.

[0042] The perylene pigment (CAS number: 3049-71-6) represented by the above chemical formula (7) is Pigment Red 178.

[0043] The core pigment may be used alone or in combination of two or more.

[0044] (Fiber shape) In one or more embodiments of the present invention, the cross-sectional shape of the core-sheath composite fiber for artificial hair is not particularly limited and may be circular or irregular, such as oval or flattened multilobal such as flattened bilobal.

[0045] In one or more embodiments of the present invention, the flat multi-lobed shape is formed by joining two or more lobes selected from the group consisting of circles and ellipses via a recess. In one or more embodiments of the present invention, the flat bi-lobed shape is formed by joining two lobes selected from the group consisting of circles and ellipses via a recess. In the flat multi-lobed shape and the flat bi-lobed shape, the circles and / or ellipses partially overlap at the joining point. The circular or elliptical shape does not necessarily have to be a continuous arc, and includes a partially deformed approximately circular or approximately elliptical shape as long as it does not have an acute angle.

[0046] In one or more embodiments of the present invention, the cross-sectional shape of the core is not particularly limited and may be circular or irregular, such as an ellipse or a flattened multi-lobed shape such as a flattened bilobed shape.

[0047] Regarding the cross-sectional shape, irregularities of 2 μm or less occurring on the outer periphery of the fiber and / or core due to additives etc. shall not be taken into consideration.

[0048] In one or more embodiments of the present invention, from the viewpoint of further improving the feel, the cross-sectional shape of the core-sheath composite fiber for artificial hair is preferably elliptical and / or flattened multilobal, more preferably flattened multilobal, and even more preferably flattened bilobal.

[0049] In one or more embodiments of the present invention, the cross-sectional shape of the sheath-core composite fiber for artificial hair and the cross-sectional shape of the core may be the same or different.

[0050] In the sheath-core composite fiber for artificial hair according to one or more embodiments of the present invention, the fiber cross section and the core cross section preferably have the same flattened multi-lobed cross-sectional shape, with the long axis direction of the fiber cross section and the long axis direction of the core cross section substantially coincident. In one or more embodiments of the present invention, "the long axis directions of the fiber cross section and the core cross section substantially coincident" means that the angle between the long axis of the fiber cross section and the long axis of the core cross section is less than 15 degrees. When the fiber cross section and the core cross section have the same flattened multi-lobed cross-sectional shape, with the long axis directions of the fiber cross section and the long axis direction of the core cross section substantially coincident, the outer circumferential shape of the fiber cross section and the outer circumferential shape of the core are similar in shape, resulting in a uniform sheath thickness, which prevents the core from being exposed to the surface while maintaining a good texture and appearance as artificial hair.

[0051] Fig. 1 is a schematic diagram showing the cross section of a sheath-core composite fiber for artificial hair according to one example of the present invention. The sheath-core composite fiber for artificial hair 1 comprises a sheath portion 10 and a core portion 20, and both fiber 1 and core portion 20 have a flat bilobal fiber cross section in which two ovals are joined via a recess.

[0052] In the flat bilobal fiber cross section of the sheath-core composite fiber for artificial hair, it is preferable that the length (referred to as L) of the major axis of the fiber cross section, which is the longest line among the line symmetry axis and lines connecting any two points on the periphery of the fiber cross section parallel to the line symmetry axis, and the length (referred to as S1) of the first minor axis of the fiber cross section, which is the longest line connecting any two points on the periphery of the fiber cross section perpendicular to the major axis of the fiber cross section, satisfy the following formula (1): L / S1=1.1 or more and 2.0 or less (1)

[0053] Furthermore, in a flat bilobal fiber cross section, it is preferable that the length of the major axis of the core cross section (referred to as Lc), which is the longest line among the line symmetry axis and lines connecting any two points on the periphery of the core cross section parallel to the line symmetry axis, and the length of the first minor axis of the core cross section (referred to as Sc1), which is the longest line connecting any two points on the periphery of the core cross section perpendicular to the major axis of the core cross section, satisfy the following formula (2): Lc / Sc1=1.3 or more and 2.0 or less (2)

[0054] The cross-sectional shapes of the fibers and core can be controlled by using a nozzle (hole) having a shape close to the desired cross-sectional shape.

[0055] In one or more embodiments of the present invention, the core-sheath ratio of the sheath-core composite fiber for artificial hair is not particularly limited, but is preferably an area ratio of core:sheath = 2:8 to 9:1, more preferably 3:7 to 8:2, and even more preferably 4:6 to 7:3. When the core-sheath ratio is within the above range, the feel and texture of the sheath-core composite fiber for artificial hair can be made to more closely resemble human hair.

[0056] From the viewpoint of suitability for artificial hair, the core-sheath composite fiber for artificial hair of the present invention preferably has a single fiber fineness of 10 dtex or more and 150 dtex or less, more preferably 30 dtex or more and 120 dtex or less, even more preferably 40 dtex or more and 100 dtex or less, and particularly preferably 50 dtex or more and 90 dtex or less.

[0057] In the sheath-core composite fiber for artificial hair according to one or more embodiments of the present invention, when the fiber is an aggregate of fibers, for example, a fiber bundle, it is not necessary for all fibers to have the same fineness or cross-sectional shape, and fibers having different finenesses and cross-sectional shapes may be mixed.

[0058] (Fiber composition) In one or more embodiments of the present invention, the sheath is made of a polyamide-based resin composition (hereinafter also referred to as sheath resin composition) containing a polyamide-based resin as a main component, resulting in a good feel. In one or more embodiments of the present invention, the "polyamide-based resin composition containing a polyamide-based resin as a main component" means that, when the total weight of the polyamide-based resin composition is taken as 100% by weight, the polyamide-based resin composition contains 55% by weight or more, more preferably 60% by weight or more, even more preferably 67% by weight or more, even more preferably 75% by weight or more, even more preferably 85% by weight or more, even more preferably 90% by weight or more, and even more preferably 95% by weight or more.

[0059] The polyamide resin refers to a nylon resin obtained by polymerizing one or more members selected from the group consisting of lactams, aminocarboxylic acids, mixtures of dicarboxylic acids and diamines, mixtures of dicarboxylic acid derivatives and diamines, and salts of dicarboxylic acids and diamines.

[0060] Specific examples of the lactam include, but are not limited to, 2-azetidinone, 2-pyrrolidinone, δ-valerolactam, ε-caprolactam, enantholactam, capryllactam, undecalactam, and laurolactam. Among these, ε-caprolactam, undecalactam, and laurolactam are preferred, and ε-caprolactam is particularly preferred. These lactams may be used alone or in a mixture of two or more.

[0061] Specific examples of the aminocarboxylic acid include, but are not limited to, 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Among these, 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid are preferred, with 6-aminocaproic acid being particularly preferred. These aminocarboxylic acids may be used alone or in combination of two or more.

[0062] Specific examples of dicarboxylic acids used in the mixture of dicarboxylic acid and diamine, the mixture of dicarboxylic acid derivative and diamine, or the salt of dicarboxylic acid and diamine include, but are not limited to, aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanediol, dodecanediol, brassicic acid, tetradecanediol, pentadecanedioic acid, and octadecanedioic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. Among these, adipic acid, sebacic acid, dodecanediol, terephthalic acid, and isophthalic acid are preferred, with adipic acid, terephthalic acid, and isophthalic acid being particularly preferred. These dicarboxylic acids may be used alone or in a mixture of two or more.

[0063] The dicarboxylic acid and the diamine mixture, the dicarboxylic acid derivative and the diamine mixture, or the dicarboxylic acid and the diamine salt are used. Specific examples of the diamine include, but are not limited to, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 2-methyl-1,5-diaminopentane (MDP), 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diamino Examples of suitable diamines include aliphatic diamines such as tetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, and 1,20-diaminoeicosane; alicyclic diamines such as cyclohexanediamine and bis-(4-aminohexyl)methane; and aromatic diamines such as m-xylylenediamine and p-xylylenediamine. Among these, aliphatic diamines are particularly preferred, with hexamethylenediamine being particularly preferred. These diamines may be used alone or in a mixture of two or more.

[0064] The polyamide resin (sometimes referred to as nylon resin) is not particularly limited, but it is preferable to use, for example, nylon 6, nylon 66, nylon 11, nylon 12, nylon 6·10, nylon 6·12, semi-aromatic nylons containing nylon 6T and / or 6I units, and copolymers of these nylon resins. In particular, nylon 6, nylon 66, and copolymers of nylon 6 and nylon 66 are more preferable.

[0065] The polyamide resin can be produced, for example, by a polyamide resin polymerization method in which a polyamide resin raw material is heated in the presence or absence of a catalyst. The polymerization may be performed with or without stirring, but stirring is preferred to obtain a homogeneous product. The polymerization temperature can be set arbitrarily depending on the polymerization degree, reaction yield, and reaction time of the target polymer, but a low temperature is preferred in terms of the quality of the final polyamide resin. The reaction rate can also be set arbitrarily. There are no restrictions on the pressure, but it is preferable to reduce the pressure in the system in order to efficiently remove volatile components from the system.

[0066] The polyamide resin may be end-capping with an end-capping agent such as a carboxylic acid compound or an amine compound, if necessary. When end-capping is performed by adding a monocarboxylic acid or a monoamine, the concentration of terminal amino groups or terminal carboxyl groups in the resulting nylon resin is lower than when the end-capping agent is not used. On the other hand, when end-capping is performed with a dicarboxylic acid or a diamine, the sum of the concentrations of terminal amino groups and terminal carboxyl groups does not change, but the concentration ratio of terminal amino groups to terminal carboxyl groups does change.

[0067] Specific examples of the carboxylic acid compound include, but are not limited to, aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, myristoleic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and arachic acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid and methylcyclohexanecarboxylic acid; benzoic acid, toluic acid, and ethylbenzoic acid. aromatic monocarboxylic acids such as benzoic acid and phenylacetic acid; aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassicic acid, tetradecanedioic acid, pentadecanedioic acid, and octadecanedioic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.

[0068] Specific examples of the amine compound include, but are not limited to, aliphatic monoamines such as butylamine, pentylamine, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, nonadecylamine, and icosylamine; alicyclic monoamines such as cyclohexylamine and methylcyclohexylamine; aromatic monoamines such as benzylamine and β-phenylethylamine; 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminopentane, and 1,6-diaminopentane; aliphatic diamines such as cyclohexanediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, and 1,20-diaminoeicosane; alicyclic diamines such as cyclohexanediamine and bis-(4-aminohexyl)methane; and aromatic diamines such as xylylenediamine.

[0069] The terminal group concentration of the polyamide resin is not particularly limited, but when it is necessary to improve dyeability in fiber applications or when designing a material suitable for alloying in resin applications, a high terminal amino group concentration is preferable. Conversely, when it is desired to suppress coloration and gelation under long-term aging conditions, a low terminal amino group concentration is preferable. Furthermore, when it is desired to suppress lactam regeneration during remelting, thread breakage during melt spinning due to oligomer generation, mold deposits during continuous injection molding, and die marks during continuous film extrusion, it is preferable that both the terminal carboxyl group concentration and the terminal amino group concentration are low. The terminal group concentration may be adjusted depending on the application, but both the terminal amino group concentration and the terminal carboxyl group concentration are preferably 1.0 × 10 -5 ~15.0×10 -5 eq / g, more preferably 2.0 x 10 -5~12.0×10 -5 eq / g, particularly preferably 3.0×10 -5 ~11.0×10 -5 In this specification, a range of values ​​indicated by "... to..." includes both end values, just like a range of values ​​indicated by "not less than... and not more than...".

[0070] The end-capping agent may be added by simultaneously charging it with raw materials such as caprolactam at the beginning of polymerization, by adding it during polymerization, or by adding it when the nylon resin is passed through a vertical agitation-type thin-film evaporator in a molten state. The end-capping agent may be added as is, or may be added after dissolving it in a small amount of solvent.

[0071] From the viewpoints of resin properties, versatility, and cost, the polyamide resin is preferably at least one selected from the group consisting of nylon 6 and nylon 66. In one embodiment of the present invention, "a polyamide resin mainly composed of at least one selected from the group consisting of nylon 6 and nylon 66" means a polyamide resin containing 80 mol % or more of nylon 6 and / or nylon 66.

[0072] The sheath resin composition is not particularly limited, but preferably contains 0.5 to 20 parts by weight of the sheath pigment per 100 parts by weight of polyamide resin, more preferably 1 to 15 parts by weight, and even more preferably 3 to 10 parts by weight. By containing 0.5 parts by weight or more of the sheath pigment per 100 parts by weight of polyamide resin, color development is further improved. By containing 20 parts by weight or less of the sheath pigment per 100 parts by weight of polyamide resin, spinnability is further improved.

[0073] The pigment for the sheath is not particularly limited, but is preferably used in the form of a masterbatch. Specifically, a masterbatch of the pigment for the sheath can be used, which is prepared by adding the pigment for the sheath to a polyamide resin, melt-kneading the mixture, and pelletizing the mixture. As the polyamide resin, any of those mentioned above can be used as appropriate, and the same polyamide resin as the main component of the sheath can also be used.

[0074] The polyamide resin composition constituting the sheath may contain other resins in addition to the polyamide resin. Examples of the other resins include vinyl chloride resins, modacrylic resins, polycarbonate resins, polyolefin resins, and polyphenylene sulfide resins. The other resins may be used alone or in combination of two or more.

[0075] In one or more embodiments of the present invention, the core is composed of a polyester-based resin composition containing a polyester-based resin as a main component (hereinafter also referred to as a core resin composition). In one or more embodiments of the present invention, the "polyester-based resin composition containing a polyester-based resin as a main component" means that, when the total weight of the polyester-based resin composition is 100% by weight, the polyester-based resin content is 55% by weight or more, preferably 60% by weight or more, more preferably 67% by weight or more, even more preferably 75% by weight or more, even more preferably 85% by weight or more, even more preferably 90% by weight or more, and even more preferably 95% by weight or more.

[0076] From the viewpoints of physical properties, versatility, and cost, the polyester resin is preferably at least one selected from the group consisting of polyalkylene terephthalate and copolymer polyesters mainly composed of polyalkylene terephthalate. In one or more embodiments of the present invention, the term "copolymer polyester mainly composed of polyalkylene terephthalate" refers to a copolymer polyester containing 80 mol % or more of polyalkylene terephthalate.

[0077] The polyalkylene terephthalate is not particularly limited, but examples thereof include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polycyclohexanedimethylene terephthalate.

[0078] The copolymer polyester mainly composed of polyalkylene terephthalate is not particularly limited, and examples thereof include copolymer polyesters mainly composed of polyalkylene terephthalate such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polycyclohexanedimethylene terephthalate and containing other copolymerization components.

[0079] Examples of the other copolymerization components include polycarboxylic acids and derivatives thereof, such as isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, trimellitic acid, pyromellitic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; dicarboxylic acids and derivatives thereof, including sulfonates such as 5-sodium sulfoisophthalic acid and 5-dihydroxyethyl sodium sulfoisophthalate; 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, diethylene glycol, polyethylene glycol, trimethylolpropane, pentaerythritol, 4-hydroxybenzoic acid, ε-caprolactone, and ethylene glycol ether of bisphenol A.

[0080] From the viewpoints of stability and ease of operation, the copolymer polyester is preferably produced by reacting a main polyalkylene terephthalate with a small amount of other copolymerization component. As the polyalkylene terephthalate, a polymer of terephthalic acid and / or a derivative thereof (e.g., methyl terephthalate) and alkylene glycol can be used. The copolymer polyester may also be produced by polymerizing a mixture of terephthalic acid and / or a derivative thereof (e.g., methyl terephthalate) and alkylene glycol, which is used in the polymerization of the main polyalkylene terephthalate, with a small amount of other copolymerization component, a monomer or oligomer component.

[0081] The copolymer polyester may be any polyester in which the other copolymer component is polycondensed with the main chain and / or side chain of the main polyalkylene terephthalate, and there are no particular limitations on the copolymerization method.

[0082] Specific examples of the copolymer polyester mainly composed of polyalkylene terephthalate include polyesters mainly composed of polyethylene terephthalate copolymerized with one compound selected from the group consisting of ethylene glycol ether of bisphenol A, 1,4-cyclohexadimethanol, isophthalic acid, and 5-dihydroxyethyl sodium sulfoisophthalate.

[0083] The polyalkylene terephthalates and copolymer polyesters mainly composed of polyalkylene terephthalates may be used alone or in combination of two or more thereof. Among them, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyesters mainly composed of polyethylene terephthalate copolymerized with ethylene glycol ether of bisphenol A, polyesters mainly composed of polyethylene terephthalate copolymerized with 1,4-cyclohexanedimethanol, polyesters mainly composed of polyethylene terephthalate copolymerized with isophthalic acid, and polyesters mainly composed of polyethylene terephthalate copolymerized with 5-dihydroxyethyl sodium sulfoisophthalate are preferably used alone or in combination of two or more thereof.

[0084] The intrinsic viscosity (sometimes referred to as IV value) of the polyester resin is not particularly limited, but is preferably 0.3 dL / g or more and 1.2 dL / g or less, and more preferably 0.4 dL / g or more and 1.0 dL / g or less. When the intrinsic viscosity is 0.3 dL / g or more, the mechanical strength of the resulting fiber does not decrease, and there is no risk of dripping during a combustion test. Furthermore, when the intrinsic viscosity is 1.2 dL / g or less, the molecular weight does not increase too much, the melt viscosity does not become too high, melt spinning is easy, and the fineness tends to be uniform.

[0085] The core resin composition is not particularly limited, but preferably contains 0.5 to 20 parts by weight of the core pigment per 100 parts by weight of polyester-based resin, more preferably 1 to 15 parts by weight, and even more preferably 3 to 10 parts by weight. By containing 0.5 parts by weight or more of the core pigment per 100 parts by weight of polyester-based resin, color development is further improved. By containing 20 parts by weight or less of the core pigment per 100 parts by weight of polyester-based resin, spinnability is further improved.

[0086] The core pigment is not particularly limited, but is preferably used in the form of a masterbatch. Specifically, a masterbatch of the core pigment can be used, which is prepared by adding the core pigment to a polyester resin, melt-kneading the mixture, and pelletizing the mixture. As the polyester resin, any of those described above can be used as appropriate, and the same polyester resin as the main component of the core can also be used.

[0087] The polyester resin composition constituting the core may contain other resins in addition to the polyester resin as the main component resin. Examples of the other resins include polyamide resins, vinyl chloride resins, modacrylic resins, polycarbonate resins, polyolefin resins, and polyphenylene sulfide resins. One type of the other resins may be used alone, or two or more types may be used in combination.

[0088] From the viewpoint of making the feel and appearance of the core-sheath composite fiber for artificial hair more similar to human hair and further improving curling properties and curl retention, the core is preferably composed of a polyester-based resin composition containing, as a main component, one or more polyester-based resins selected from the group consisting of polyalkylene terephthalates and copolymer polyesters mainly composed of polyalkylene terephthalates, and the sheath is more preferably composed of a polyamide-based resin composition containing, as a main component, at least one polyamide-based resin selected from the group consisting of nylon 6 and nylon 66.

[0089] In one or more embodiments of the present invention, a flame retardant may be used in combination from the viewpoint of flame retardancy. Examples of the flame retardant include bromine-containing flame retardants and phosphorus-containing flame retardants. Examples of the phosphorus-containing flame retardant include phosphate ester amide compounds and organic cyclic phosphorus compounds. The bromine-containing flame retardant is not particularly limited, but examples thereof include brominated epoxy flame retardants; bromine-containing phosphate esters such as pentabromotoluene, hexabromobenzene, decabromodiphenyl, decabromodiphenyl ether, bis(tribromophenoxy)ethane, tetrabromophthalic anhydride, ethylene bis(tetrabromophthalimide), ethylene bis(pentabromophenyl), octabromotrimethylphenylindane, and tris(tribromoneopentyl)phosphate; brominated polystyrenes; brominated polybenzyl acrylates; and bromine brominated phenoxy resins; brominated polycarbonate oligomers; tetrabromobisphenol A derivatives such as tetrabromobisphenol A, tetrabromobisphenol A-bis(2,3-dibromopropyl ether), tetrabromobisphenol A-bis(allyl ether), and tetrabromobisphenol A-bis(hydroxyethyl ether); bromine-containing triazine compounds such as tris(tribromophenoxy)triazine; and bromine-containing isocyanuric acid compounds such as tris(2,3-dibromopropyl)isocyanurate. Among these, brominated epoxy flame retardants are preferably used from the viewpoints of heat resistance and flame retardancy.

[0090] The brominated epoxy flame retardant may be a brominated epoxy flame retardant having an epoxy group or tribromophenol at the molecular terminal as a raw material. However, the structure of the brominated epoxy flame retardant after melt-kneading is not particularly limited. When the total number of structural units represented by the following chemical formula (8) and structural units obtained by modifying at least a portion of the following formula (8) is taken as 100 mol %, it is preferable that 80 mol % or more of the structural units represented by the following chemical formula (8) are the structural units represented by the following chemical formula (8). The structure of the brominated epoxy flame retardant may be changed at the molecular terminal after melt-kneading. For example, the molecular terminal of the brominated epoxy flame retardant may be substituted with a group other than an epoxy group or tribromophenol, such as a hydroxyl group, a phosphate group, or a phosphonic acid group, or the molecular terminal may be bonded to a polyester component via an ester group.

[0091] [ka]

[0092] Furthermore, the structure of the brominated epoxy flame retardant may be partially changed other than at the molecular terminals. For example, the secondary hydroxyl group and the epoxy group of the brominated epoxy flame retardant may be bonded to form a branched structure, and some of the bromine atoms in the chemical formula (8) may be eliminated or added, provided that the bromine content in the brominated epoxy flame retardant molecule does not change significantly.

[0093] As the brominated epoxy flame retardant, for example, a polymeric brominated epoxy flame retardant as shown in the following chemical formula (9) is preferably used. In the following formula (9), m is 1 to 1000. As the polymeric brominated epoxy flame retardant as shown in the following chemical formula (9), for example, a commercially available product such as a brominated epoxy flame retardant manufactured by Sakamoto Yakuhin Kogyo Co., Ltd. (product name "SR-T2MP") may be used.

[0094] [ka]

[0095] The brominated epoxy flame retardant is not particularly limited, but is preferably contained in the core and / or sheath in an amount of 5 to 40 parts by weight per 100 parts by weight of the main component resin. For example, from the viewpoint of heat resistance and flame retardancy, the core is preferably composed of a polyester-based resin composition containing 100 parts by weight of one or more polyester-based resins selected from the group consisting of polyalkylene terephthalates and copolymer polyesters mainly composed of polyalkylene terephthalates, 5 to 40 parts by weight of a brominated epoxy flame retardant, and 0.5 to 20 parts by weight of a pigment for the core, and the sheath is preferably composed of a polyamide-based resin composition containing 100 parts by weight of a polyamide-based resin mainly composed of at least one selected from the group consisting of nylon 6 and nylon 66, 5 to 40 parts by weight of a brominated epoxy flame retardant, and 0.5 to 20 parts by weight of a pigment for the sheath.

[0096] In one or more embodiments of the present invention, a flame retardant aid may be used in combination. The flame retardant aid is not particularly limited, but from the viewpoint of flame retardancy, it is preferable to use an antimony-based compound or a composite metal containing antimony. Examples of the antimony-based compound include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium antimonate, potassium antimonate, and calcium antimonate. In terms of the effect of improving flame retardancy and the influence on the touch, one or more selected from the group consisting of antimony trioxide, antimony pentoxide, and sodium antimonate are more preferable.

[0097] The flame retardant aid is not particularly limited, but is preferably contained in the core and / or sheath in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the main component resin, for example.

[0098] The core-sheath composite fiber for artificial hair may contain various additives such as heat-resistant agents, stabilizers, fluorescent agents, antioxidants, and antistatic agents, as needed, within the range that does not impair the effects of the present invention.

[0099] (Manufacturing method) The core-sheath composite fiber for artificial hair of the present invention can be produced by melt-kneading the resin compositions constituting the core and sheath separately using various common kneaders, and then melt-spinning the mixture using a core-sheath composite nozzle.

[0100] For example, the polyester-based resin composition obtained by dry-blending the above-mentioned polyester-based resin, the pigment for the core (which may be a masterbatch of the pigment for the core), the brominated epoxy-based flame retardant, and other components can be melt-kneaded using any of various general kneaders to form the core component that constitutes the core, while the polyamide-based resin composition obtained by dry-blending the above-mentioned polyamide-based resin, the pigment for the sheath (which may be a masterbatch of the pigment for the sheath), the brominated epoxy-based flame retardant, and other components can be melt-kneaded using any of various general kneaders to form the sheath component that constitutes the sheath, and then melt-spinning the sheath component using a composite spinning nozzle.

[0101] The masterbatch of the core pigment can be obtained, for example, by dry-blending the above-mentioned polyester resin and the core pigment, followed by melt-kneading using any of various common kneaders and pelletizing.

[0102] The masterbatch of the sheath pigment can be obtained, for example, by dry-blending the above-mentioned polyamide resin and sheath pigment, followed by melt-kneading and pelletizing using any of various common kneaders.

[0103] Examples of the kneader include a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, a kneader, etc. Among these, a twin-screw extruder is preferred from the viewpoints of adjusting the degree of kneading and ease of operation.

[0104] In the melt spinning method, for example, in the case of a polyester-based resin composition, the temperature of the extruder, gear pump, nozzle, etc. is set to 250°C or higher and 300°C or lower, and in the case of a polyamide-based resin composition, the temperature of the extruder, gear pump, nozzle, etc. is set to 260°C or higher and 320°C or lower, and melt spinning is performed.The spun yarn is passed through a heating barrel, cooled to below the glass transition point of each resin, and taken up at a speed of 30 m / min or higher and 5000 m / min or lower to obtain a spun yarn (undrawn yarn).

[0105] Specifically, during melt spinning, the polyester resin composition that constitutes the core is supplied by a core extruder of the melt spinning machine, and the polyamide resin composition that constitutes the sheath is supplied by a sheath extruder of the melt spinning machine, and the molten polymer is extruded through a core-sheath composite spinning nozzle (hole) having a predetermined shape to obtain a spun yarn (undrawn yarn).

[0106] The spun yarn (undrawn yarn) is preferably hot-drawn. The drawing may be performed by either a two-step method in which the spun yarn is once wound up and then drawn, or a direct spin-drawing method in which the spun yarn is continuously drawn without being wound up. Hot-drawing is performed by a one-stage drawing method or a multi-stage drawing method of two or more stages. Heating means for hot-drawing may include a heated roller, a heat plate, a steam jet device, a hot water bath, etc., and these may also be used in combination as appropriate.

[0107] In one or more embodiments of the present invention, the core-sheath composite fiber for artificial hair may be treated with an oil such as a fiber treatment agent or a softener to make the feel and texture closer to that of human hair.

[0108] Examples of the fiber treatment agent include silicone-based fiber treatment agents and non-silicone-based fiber treatment agents for improving the feel and combability.

[0109] The core-sheath composite fiber for artificial hair may be subjected to gear crimping, which gives the fiber a gentle bend, resulting in a natural appearance and improving combability by reducing adhesion between the fibers.

[0110] In the gear crimping process, the fiber is generally heated to above its softening temperature and passed between two meshing gears, and the shape of the gears is transferred to the fiber, thereby creating a bent shape. Furthermore, if necessary, different curl shapes can be created by heat-treating the core-sheath composite fiber for artificial hair at different temperatures during the fiber production stage.

[0111] (headdress products) In one or more embodiments of the present invention, the core-sheath composite fiber for artificial hair can be suitably used for head accessories. The head accessories are not particularly limited, but preferably include one selected from the group consisting of hair wigs, hairpieces, weaving, hair extensions, braided hair, hair accessories, and doll hair. From the viewpoint of more effectively exhibiting sufficiently excellent curl setting properties, hair wigs and weaving are more preferred.

[0112] In one or more embodiments of the present invention, the sheath-core composite fiber for artificial hair may be used alone as artificial hair, or may be used in combination with other artificial hair fibers or natural fibers such as human hair or animal hair. The head accessory product may be composed solely of the sheath-core composite fiber for artificial hair according to one or more embodiments of the present invention, or may be composed in combination with other artificial hair fibers or natural fibers such as human hair or animal hair. Examples of other artificial hair fibers include acrylic fibers. [Example]

[0113] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0114] The measurement and evaluation methods used in the examples and comparative examples are as follows.

[0115] (single fiber fineness) Measurements were made using an auto-blow type fineness measuring instrument "DENIER COMPUTER Type DC-11" (manufactured by Search Co.), and the average value of the measurements for 30 samples was calculated to obtain the single fiber fineness.

[0116] (Core-sheath ratio) The fibers were bundled at room temperature, fixed with a shrink tube to prevent the fiber bundle (total fineness 550 dtex) from shifting, and then sliced ​​with a cutter to prepare fiber bundles for cross-sectional observation. These fiber bundles were photographed at 500x magnification with a laser microscope (Keyence Corporation, "VK-9500"), and the core-sheath ratio was calculated based on the obtained fiber cross-sectional photograph.

[0117] (Tactile sensation) A sensory evaluation was conducted by a professional hairdresser and rated on the following three-point scale. A: Very good texture similar to human hair B: Slightly inferior to human hair, but has a good feel

[0118] (Color development) <L of fiber bundle * a * b * Value Measurement> The fibers were bundled at room temperature and fixed with a shrink tube to prevent the fiber bundle (total fineness 700,000 dtex) from shifting, to prepare a fiber bundle for color measurement. The color tone of the fiber bundle for color measurement was measured using a color tone measuring device ("MAMBO" manufactured by Bossa Nova Technologies). * a * b * The value was obtained. <L of pigment masterbatch * a * b * Value Measurement> The pigment master batch for the sheath was pressed using a transfer molding machine to make a 5cm x 5cm plate (3mm thick). The color tone was measured using the reflectance measurement mode of a VSS-400 (manufactured by Nippon Denshoku Industries Co., Ltd.). * a * b * In Comparative Examples 1 and 2, a masterbatch of Pigment 2 was used. <Evaluation> L of the fiber bundle obtained above * a * b * Value and L of pigment masterbatch * a* b * The values ​​were compared and the color development was evaluated according to the following four-level scale: A means that the color development is good, and B to D means that the color development is poor. A: When comparing both measurements, L * , a * , and b * The difference between the three values ​​is 10 or less. B: When comparing both measurements, L * , a * , and b * There are two values ​​where the difference between each is 10 or less. C: When comparing both measurements, L * , a * , and b * There is one where the difference between the values ​​of is 10 or less. D: When comparing both measurements, L * , a * , and b * The difference between the values ​​of all three is greater than 10.

[0119] (Spinnability) Good: No yarn breakage occurs during 5 minutes of spinning. Poor: Yarn breakage occurs once or more within 5 minutes of spinning, or spinning is not possible.

[0120] In the examples and comparative examples, the following pigments were used. Pigment 1: Pigment Yellow 147 Pigment 2: Pigment Yellow 150 Pigment 3: Acid Orange 74 Pigment 4: Bis[3-hydroxy-4-[(2-hydroxy-3,5-dinitrophenyl)azo]-N-phenyl-2-naphthalenecarboxamido(2-)]hydrogenchromate Pigment 5: Hansa Yellow Pigment 6: Pigment Yellow 62

[0121] (Production Example 1) 10 parts by weight of pigment 1 was added to 100 parts by weight of polyethylene terephthalate pellets (manufactured by East West Chemical Private Limited, EastPET product name "A-12"), and after dry blending, the mixture was fed into a twin-screw extruder, melt-kneaded at a barrel setting temperature of 280°C, and pelletized to obtain a masterbatch of pigment 1.

[0122] (Production Example 2) 10 parts by weight of pigment 2 was added to 100 parts by weight of nylon 6 (manufactured by Unitika, product name "A1030BRL"), and after dry blending, the mixture was fed into a twin-screw extruder, melt-kneaded at a barrel setting temperature of 260°C, and pelletized to obtain a masterbatch of pigment 2.

[0123] (Production Example 3) A masterbatch of Pigment 3 was obtained in the same manner as in Production Example 2, except that Pigment 3 was used instead of Pigment 2.

[0124] (Production Example 4) A masterbatch of Pigment 4 was obtained in the same manner as in Production Example 2, except that Pigment 4 was used instead of Pigment 2.

[0125] (Production Example 5) A masterbatch of Pigment 5 was obtained in the same manner as in Production Example 2, except that Pigment 5 was used instead of Pigment 2.

[0126] (Production Example 6) A masterbatch of Pigment 6 was obtained in the same manner as in Production Example 2, except that Pigment 6 was used instead of Pigment 2.

[0127] Example 1 To 100 parts by weight of polyethylene terephthalate pellets (manufactured by East West Chemical Private Limited, EastPET trade name "A-12", hereinafter also referred to as "PET"), 30 parts by weight of a brominated epoxy flame retardant (manufactured by Sakamoto Yakuhin Kogyo, trade name "SR-T2MP"), 3 parts by weight of sodium antimonate (manufactured by Nippon Seiko, trade name "SA-A"), and 5 parts by weight of a masterbatch of pigment 1 were added, dry blended, and then fed into a twin-screw extruder, melt-kneaded at a barrel set temperature of 280°C, and pelletized to obtain a polyester resin composition.

[0128] Next, 12 parts by weight of a brominated epoxy flame retardant (manufactured by Sakamoto Yakuhin Kogyo, trade name "SR-T2MP"), 2 parts by weight of sodium antimonate (manufactured by Nippon Seiko, trade name "SA-A"), and 5 parts by weight of a masterbatch of pigment 3 were added to 100 parts by weight of nylon 6 (manufactured by Unitika, trade name "A1030BRL", hereinafter also referred to as "PA6"), and after dry blending, the mixture was fed into a twin-screw extruder, melt-kneaded at a barrel setting temperature of 260°C, and pelletized to obtain a polyamide resin composition.

[0129] Next, the pellet-like polyester resin composition and polyamide resin composition were each fed into an extruder, extruded through a core-sheath type composite spinning nozzle (both the fiber cross section and the core cross section of the nozzle were flattened bilobe-shaped) at a nozzle set temperature of 270°C, and wound up at a speed of 40 to 200 m / min to obtain an undrawn core-sheath composite fiber yarn with the polyester resin composition as the core and the polyamide resin composition as the sheath, with a core-sheath ratio of 5:5 in terms of area ratio.

[0130] The resulting undrawn yarn was drawn using a heated roll at 85°C while being taken up at a speed of 45 m / min to obtain a 3x drawn yarn, which was then continuously taken up at a speed of 45 m / min using a heated roll heated to 205°C and subjected to heat treatment. A polyether-based oil agent (Marubishi Yuka Kogyo, product name "KWC-Q") was applied to the yarn to a concentration of 0.20% omf (pure oil agent weight percentage relative to the dry fiber weight), and the yarn was then dried to obtain a core-sheath composite fiber.

[0131] Example 2 A core-sheath composite fiber was obtained in the same manner as in Example 1, except that a masterbatch of pigment 4 was used instead of a masterbatch of pigment 3 to prepare a polyamide-based resin composition.

[0132] Example 3 A core-sheath composite fiber was obtained in the same manner as in Example 1, except that a masterbatch of pigment 2 was used instead of a masterbatch of pigment 3 to prepare a polyamide-based resin composition.

[0133] Example 4 A core-sheath composite fiber was obtained in the same manner as in Example 1, except that a masterbatch of pigment 5 was used instead of the masterbatch of pigment 3 to prepare a polyamide resin composition.

[0134] (Comparative Example 1) To 100 parts by weight of polyethylene terephthalate pellets (East West Chemical Private Limited, EastPET trade name "A-12"; hereafter also referred to as "PET"), 30 parts by weight of a brominated epoxy flame retardant (Sakamoto Yakuhin Kogyo, trade name "SR-T2MP"), 3 parts by weight of sodium antimonate (Nihon Seiko, trade name "SA-A"), and 5 parts by weight of a masterbatch of pigment 2 were added. The mixture was dry-blended and fed into a twin-screw extruder. The barrel was set to a temperature of 280°C, melt-kneaded, and pelletized to obtain a polyester resin composition. The resulting polyester resin composition was extruded through a spinning nozzle with a 2 mm round cross-section nozzle hole at a nozzle set temperature of 270°C and wound at a speed of 40 to 200 m / min to obtain an undrawn yarn.

[0135] The resulting unstretched yarn was stretched while being taken up at a speed of 45 m / min using a heated roll at 85°C to obtain a 3x stretched yarn, which was then continuously taken up at a speed of 45 m / min using a heated roll heated to 205°C and subjected to heat treatment.A polyether-based oil agent (Marubishi Yuka Kogyo, product name "KWC-Q") was applied to the yarn to a concentration of 0.20% omf (pure oil agent weight percentage relative to the dry fiber weight), and the resulting yarn was then dried to obtain a PET fiber.

[0136] (Comparative Example 2) A polyamide-based resin composition prepared in the same manner as in Example 3 was extruded through a spinning nozzle having a round cross-section nozzle hole with a nozzle diameter of 2 mm at a nozzle setting temperature of 270°C and wound up at a speed of 40 to 200 m / min, but due to poor spinnability, fibers could not be obtained.

[0137] (Comparative Example 3) Core-sheath composite fibers were obtained in the same manner as in Example 1, except that a polyester-based resin composition was prepared using a masterbatch of pigment 2 instead of a masterbatch of pigment 1, and a polyamide-based resin composition was prepared using a masterbatch of pigment 2 instead of a masterbatch of pigment 3.

[0138] Comparative Example 4 A core-sheath composite fiber was obtained in the same manner as in Example 1, except that a masterbatch of pigment 1 was used instead of a masterbatch of pigment 3 to prepare a polyamide-based resin composition.

[0139] (Comparative Example 5) A core-sheath composite fiber was obtained in the same manner as in Example 1, except that a masterbatch of pigment 6 was used instead of a masterbatch of pigment 3 to prepare a polyamide-based resin composition.

[0140] In the examples and comparative examples, the feel, color development and spinnability were measured and evaluated as described above, and the results are shown in Table 1 below.

[0141] [Table 1]

[0142] Figure 2 is a laser microscope photograph (1000x magnification) of the fiber cross section of the fiber of Example 1. As can be seen from Figure 2, in the core-sheath composite fiber for artificial hair, both the fiber cross section and the core had a flat bilobal cross section.

[0143] As can be seen from the data in Table 1 above, the fibers of Examples 1 to 4 had a feel similar to human hair, and also had good color development and spinnability.

[0144] On the other hand, the fiber of Comparative Example 1, which used a polyester resin composition containing nickel complex pigment (a), had poor color development. As mentioned above, no fiber was obtained from Comparative Example 2. The fibers of Comparative Examples 3 and 4, in which the same pigment was used in the core as in the sheath, had poor color development. The fiber of Comparative Example 5, in which one or more organic pigments selected from the group consisting of nickel complex pigment (a), chromium complex pigment (b), and nitro group-containing organic pigment (c) were not used in the sheath, also had poor color development.

[0145] The present invention is not particularly limited, but preferably includes at least the following embodiments. [1] A core-sheath composite fiber for artificial hair, comprising a core and a sheath, the core is made of a polyester-based resin composition containing a polyester-based resin as a main component, and the sheath is made of a polyamide-based resin composition containing a polyamide-based resin as a main component, the sheath portion contains one or more organic pigments selected from the group consisting of (a) nickel complex pigments in which nickel and an organic dye structure are coordinated in a 1:1 or 1:2 ratio, (b) chromium complex pigments in which chromium and an organic dye structure are coordinated in a 1:1 or 1:2 ratio, and (c) metal-free organic pigments containing a nitro group; A core-sheath composite fiber for artificial hair, characterized in that the core contains a pigment different from that of the sheath. [2] The core-sheath composite fiber for artificial hair according to [1], wherein the core is composed of a polyester-based resin composition containing one or more polyester-based resins selected from the group consisting of polyalkylene terephthalates and copolymer polyesters mainly composed of polyalkylene terephthalates. [3] The core-sheath composite fiber for artificial hair according to [1] or [2], wherein the sheath is made of a polyamide-based resin composition containing a polyamide-based resin mainly composed of at least one selected from the group consisting of nylon 6 and nylon 66. [4] The core-sheath composite fiber for artificial hair according to any one of [1] to [3], wherein the organic pigment contained in the sheath portion is at least one selected from the group consisting of azo pigments and azomethine pigments. [5] The core-sheath composite fiber for artificial hair according to any one of [1] to [4], wherein the core contains an anthraquinone pigment. [6] The sheath-core composite fiber for artificial hair according to any one of [1] to [5], wherein the sheath-core composite fiber for artificial hair has a flat bilobal cross section. [7] The core-sheath composite fiber for artificial hair according to any one of [1] to [6], wherein the core has a flat bilobal cross-sectional shape. [8] A head accessory comprising the core-sheath composite fiber for artificial hair according to any one of [1] to [7]. [9] The head accessory product according to [8], which is one selected from the group consisting of hair wigs, hairpieces, weaving, hair extensions, braided hair, hair accessories and doll hair.

[10] A method for producing a core-sheath composite fiber for artificial hair according to any one of [1] to [7], a step of preparing a sheath pigment masterbatch by mixing, with a polyamide resin, one or more sheath pigments selected from the group consisting of (a) a nickel complex pigment in which nickel and an organic dye structure are coordinated in a 1:1 or 1:2 ratio, (b) a chromium complex pigment in which chromium and an organic dye structure are coordinated in a 1:1 or 1:2 ratio, and (c) a metal-free organic pigment containing a nitro group; a step of mixing a pigment different from the pigment for the sheath with a polyester resin to prepare a pigment masterbatch for the core; and A method for producing a core-sheath composite fiber for artificial hair, comprising the step of melt-spinning a core resin composition and a sheath resin composition using a core-sheath composite nozzle. [Explanation of symbols]

[0146] 1. Core-sheath composite fiber for artificial hair (cross section) 10 Sheath 20 core

Claims

1. A core-sheath composite fiber for artificial hair, comprising a core and a sheath, the core is made of a polyester-based resin composition containing a polyester-based resin, and the sheath is made of a polyamide-based resin composition containing a polyamide-based resin, the sheath portion contains one or more organic pigments selected from the group consisting of (a) nickel complex pigments in which nickel and an organic dye structure are coordinated at a ratio of 1:1 or 1:2, (b) chromium complex pigments in which chromium and an organic dye structure are coordinated at a ratio of 1:1 or 1:2, and (c) metal-free organic pigments containing a nitro group; A core-sheath composite fiber for artificial hair, characterized in that the core contains a pigment different from that of the sheath.

2. 2. The core-sheath composite fiber for artificial hair according to claim 1, wherein the core is composed of a polyester-based resin composition containing one or more polyester-based resins selected from the group consisting of polyalkylene terephthalates and copolymer polyesters mainly composed of polyalkylene terephthalates.

3. 3. The core-sheath composite fiber for artificial hair according to claim 1 or 2, wherein the sheath portion is composed of a polyamide-based resin composition containing a polyamide-based resin mainly composed of at least one type selected from the group consisting of nylon 6 and nylon 66.

4. 4. The core-sheath composite fiber for artificial hair according to claim 1, wherein the organic pigment contained in the sheath portion is at least one selected from the group consisting of azo pigments and azomethine pigments.

5. The core-sheath composite fiber for artificial hair according to any one of claims 1 to 4, wherein the core contains an anthraquinone pigment.

6. The sheath-core composite fiber for artificial hair according to any one of claims 1 to 5, wherein the sheath-core composite fiber for artificial hair has a flat bilobal cross section.

7. The core-sheath composite fiber for artificial hair according to any one of claims 1 to 6, wherein the core has a flat bilobal cross section.

8. A head accessory comprising the core-sheath composite fiber for artificial hair according to any one of claims 1 to 7.

9. 9. The head accessory product according to claim 8, which is one selected from the group consisting of hair wigs, hairpieces, weaving, hair extensions, braided hair, hair accessories and doll hair.

10. A method for producing the core-sheath composite fiber for artificial hair according to any one of claims 1 to 7, comprising: a step of preparing a sheath pigment masterbatch by mixing, with a polyamide resin, one or more sheath pigments selected from the group consisting of (a) a nickel complex pigment in which nickel and an organic dye structure are coordinated at a ratio of 1:1 or 1:2, (b) a chromium complex pigment in which chromium and an organic dye structure are coordinated at a ratio of 1:1 or 1:2, and (c) a metal-free organic pigment containing a nitro group; a step of mixing a pigment different from the pigment for the sheath with a polyester resin to prepare a pigment masterbatch for the core; and A method for producing a core-sheath composite fiber for artificial hair, comprising the step of melt-spinning a core resin composition and a sheath resin composition using a core-sheath composite nozzle.

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