Luminous fiber and toy or ornament equipped with same

Abstract

The luminous fiber according to the present invention comprises a flat luminous pigment, a coloring pigment, and a resin, wherein: the flat luminous pigment is an iron oxide-coated flat aluminum particle having a flat aluminum particle and an iron oxide layer covering the flat aluminum particle, or is an iron oxide-coated flat silicon dioxide particle having a flat silicon dioxide particle and an iron oxide layer covering the silicon dioxide particle; and the amount of elemental iron in the flat luminous pigment is 5-400 parts by mass with respect luminous pigment.

Description

Luminous fibers and toys or ornaments containing them

[0001] The present disclosure relates to a glittering fiber. More specifically, the present disclosure relates to a glittering fiber that has excellent glittering properties and exhibits significant changes in hue and brightness depending on the viewing angle.

[0002] Conventionally, glittering fibers containing a synthetic resin and a powder of a glittering material have been known (see, for example, Patent Document 1). Patent Document 1 discloses that the glittering material can be inorganic substances such as glass, mica, silica, metal powder such as aluminum, diamonds, synthetic diamonds, pearls, and seashells. However, glittering fibers using these glittering materials have poor glittering properties and are not commercially viable, so there is room for improvement in glittering fibers.

[0003] Japanese Patent Application Laid-Open No. 2002-88565

[0004] The present disclosure has been made with a focus on the problems described above, and aims to provide a lustrous fiber that not only has excellent lustrous properties but also exhibits significant changes in hue and brightness depending on the viewing angle, as well as toys, ornaments, and the like that use this lustrous fiber.

[0005] Aspect 1 of the present invention is a glittering fiber comprising a flat bright pigment, a coloring pigment, and a resin, wherein the flat bright pigment is iron oxide-coated flat aluminum particles having flat aluminum particles and an iron oxide layer covering the flat aluminum particles, or iron oxide-coated flat silicon dioxide particles having flat silicon dioxide particles and an iron oxide layer covering the silicon dioxide particles, and the amount of iron element in the flat bright pigment is 5 to 400 parts by mass per 100 parts by mass of aluminum element or silicon element in the flat bright pigment. Aspect 2 of the present invention is the glittering fiber according to Aspect 1, wherein the coloring pigment comprises a blue pigment. Aspect 3 of the present invention is the glittering fiber according to Aspect 1 or 2, wherein the iron oxide-coated flat aluminum particles have a reflective layer containing silicon dioxide between the flat aluminum particles and the iron oxide layer. Aspect 4 of the present invention is the bright fiber according to Aspect 3, wherein the amount of silicon element in the flat bright pigment is 5 to 50 parts by mass per 100 parts by mass of aluminum element in the flat bright pigment. Aspect 5 of the present invention is the bright fiber according to any one of Aspects 1 to 4, wherein the average particle size of the flat bright pigment is 1 to 70 μm. Aspect 6 of the present invention is the bright fiber according to any one of Aspects 1 to 5, wherein the resin is selected from polyolefin, polyamide, polyester, acrylonitrile resin, polyvinyl chloride, polyvinylidene chloride, and vinyl chloride-vinylidene chloride copolymer resin. Aspect 7 of the present invention is the bright fiber according to any one of Aspects 1 to 6, wherein the flat bright pigment is blended in an amount of 0.05 to 3 mass% relative to the total mass of the bright fiber. Aspect 8 of the present invention is the bright fiber according to any one of Aspects 1 to 7, wherein a color-changing material is contained. A ninth aspect of the present invention is the glittering fiber according to any one of the first to eighth aspects, wherein the average outer diameter is 10 to 300 μm.A tenth aspect of the present invention is the photoluminescent fiber according to any one of aspects 1 to 9, wherein an absorption spectrum A of the photoluminescent fiber measured after wrapping the photoluminescent fiber one turn so as to cover at least a portion of a substrate measured as a baseline in absorption spectrum measurement, and an absorption spectrum B of the photoluminescent fiber measured after wrapping the photoluminescent fiber four turns, differ by 10 nm or more in one or more wavelengths selected from the group consisting of a first absorption maximum wavelength, a second absorption maximum wavelength, and a third absorption maximum wavelength. A eleventh aspect of the present invention is a toy or decorative article comprising the photoluminescent fiber according to any one of aspects 1 to 10.

[0006] This embodiment can provide a glossy fiber that has excellent glossiness and has the property of changing hue and brightness significantly depending on the viewing angle, making it suitable for commercial use, as well as toys, decorative items, etc. that use this glossy fiber.

[0007] 1 shows absorption spectra A (1 turn) and B (4 turns) of Example 1. FIG. 2 shows absorption spectra A (1 turn) and B (4 turns) of Example 5.

[0008] The glittering fiber according to this embodiment contains a flat glittering pigment, a coloring pigment, and a resin. Each component constituting the glittering fiber according to this embodiment will be described below.

[0009] The glittering fiber according to this embodiment comprises a flat glittering pigment. The flat glittering pigment is selected from iron oxide-coated flat aluminum particles or iron oxide-coated flat silicon dioxide particles, and also includes an embodiment comprising both iron oxide-coated flat aluminum particles and iron oxide-coated flat silicon dioxide particles. The iron oxide-coated flat aluminum particles comprise flat aluminum particles and an iron oxide layer covering the flat aluminum particles, with the surfaces of the flat aluminum particles being coated with iron oxide. The iron oxide-coated flat silicon dioxide particles comprise flat silicon dioxide particles and an iron oxide layer covering the flat silicon dioxide particles, with the surfaces of the flat silicon dioxide particles being coated with iron oxide. These flat glittering pigments have hiding properties. Hereinafter, these flat glittering pigments may be referred to as "flat particles." Note that "iron oxide" according to this embodiment refers to "iron (III) oxide (Fe ２ O ３ )"

[0010] In general, when a resin composition containing a flat bright pigment is molded by a molding method such as extrusion molding or injection molding, it is thought that the flat surfaces of the flat bright pigment tend to face in one direction within the molded product (this state is called "orientation"). However, conventional flat bright pigments sometimes lack sufficient mechanical strength. For example, in fibers obtained by extrusion molding a resin composition consisting of a conventional flat bright pigment and a resin, the flat bright pigment tends to break during the molding process, making it difficult to maintain its shape. In other words, conventional flat bright pigments have a problem in that they are difficult to orient in one direction within the fiber (molded product).

[0011] To address these problems, this embodiment uses a flat luster pigment that uses flat aluminum particles or flat silicon dioxide particles as a base material and is further coated with a certain amount of iron oxide. This significantly improves the mechanical strength while maintaining the flat shape of the aluminum particles or silicon dioxide particles, making the flat luster pigment less likely to crack and more likely to maintain its shape, even when using a molding method that applies high shear forces, such as extrusion molding. In other words, the iron oxide-coated flat aluminum particles or iron oxide-coated flat silicon dioxide particles of this embodiment are likely to be oriented in one direction within the fiber. The flat luster pigment can be used alone or in combination of two or more types.

[0012] As described above, in the brilliant fiber according to this embodiment, the flat faces of the flat brilliant pigments tend to be oriented in one direction, and light incident on the flat faces from a certain direction is reflected in a certain regular reflection direction, which allows the brilliant fiber according to this embodiment to exhibit the excellent brilliant feel (metallic luster) inherent in the flat brilliant pigments.

[0013] Furthermore, by combining a flat bright pigment with a color pigment, it is possible to impart a property in which the hue and brightness change significantly depending on the viewing angle, i.e., polarization (color flop). Specifically, the area of ​​the flat bright pigment visible from the front of the flat bright pigment (the surface facing the flat surface of the flat bright pigment) is large, and when observed from the front of the flat bright pigment, the color of the flat bright pigment and the color of the color pigment, or a mixture of these colors, is visible. On the other hand, when observed from a direction different from the front of the flat bright pigment (for example, from an oblique direction relative to the front of the flat bright pigment), the area of ​​the flat bright pigment visible is small, and when observed from a direction different from the front of the flat bright pigment, the color and brightness of the flat bright pigment are less visible, and the color of the color pigment is relatively more visible.

[0014] Furthermore, when light is irradiated onto the shiny fiber, the reflected light and the transmitted light exhibit different hues. For example, when light is irradiated onto the fiber from a certain direction, the specularly reflected light (light reflected from the surface of the fiber) is reflected by the surfaces of the flat shiny pigment and the colored pigment, and the color of the flat shiny pigment and the colored pigment, or a mixture of these colors, is visually recognized. On the other hand, when light is irradiated at an incident angle of 0°, the transmitted light (light passing through the fiber) does not transmit light due to the flat shiny pigment's hiding properties, and only the colored pigment transmits light, so the color of the colored pigment is visually recognized as being relatively stronger.

[0015] The lustrous fiber of this embodiment is obtained by combining flat aluminum particles or flat silicon dioxide particles coated with a certain amount of iron oxide as a flat lustrous pigment with a coloring pigment, thereby not only having excellent lustrous properties, but also having a lustrous fiber whose hue and brightness change significantly depending on the viewing angle due to the two polarization properties described above.

[0016] The iron oxide-coated flat aluminum particles according to this embodiment comprise flat aluminum particles (hereinafter sometimes referred to as "aluminum particles") and an iron oxide layer covering the aluminum particles. That is, the flat aluminum particles are coated with iron (III) oxide. The aluminum particles are typically particles made of aluminum. Alternatively, the aluminum particles may be particles containing aluminum as the main component, and the purity of the aluminum may be 90% by mass or more, 95% by mass or more, 99% by mass or more, etc. The aluminum particles may contain unavoidable impurities in addition to aluminum. A passivation layer may be provided between the aluminum particles and the iron oxide layer, provided that the luster or polarization of the fiber is not impaired.

[0017] The iron oxide-coated flat silicon dioxide particles according to this embodiment comprise flat silicon dioxide (silica) particles (hereinafter sometimes referred to as "silicon dioxide particles") and an iron oxide layer covering the silicon dioxide particles. That is, the flat silicon dioxide particles are coated with iron (III) oxide. The silicon dioxide particles are usually silicon dioxide (SiO ２) or particles comprising silicon dioxide. Alternatively, the silicon dioxide particles may be particles containing silicon dioxide as a main component, and the purity of the silicon dioxide particles may be 85% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, etc. The silicon dioxide particles may contain inevitable impurities in addition to silicon dioxide.

[0018] The shape of the flat bright pigment is not particularly limited as long as it can be oriented inside the fiber. From the viewpoint of orientation inside the fiber, the luster and polarization properties of the fiber, the shape of the flat bright pigment is preferably flat. Although the shape may be partially curved, it is preferable that the pigment is not curved. The shape of the surface of the flat bright pigment is not particularly limited, and examples thereof include a perfect circle, an ellipse, and a polygon.

[0019] The aluminum particles or silicon dioxide particles have a structure in which at least a portion (entire or partial) of the particles is coated with iron oxide. From the viewpoint of achieving uniform hue and brightness of the fiber, it is preferred that the entire surfaces of the aluminum particles or silicon dioxide particles are coated with iron oxide.

[0020] The degree of iron oxide coverage of aluminum particles or silicon dioxide particles is determined by the ratio of iron element in the flat bright pigment to the amount of aluminum element or silicon element in the flat bright pigment. In the flat bright pigment of this embodiment, the amount of iron element in the flat bright pigment is 5 to 400 parts by mass, preferably 10 to 350 parts by mass, and more preferably 15 to 300 parts by mass, per 100 parts by mass of aluminum element or silicon element in the flat bright pigment. Note that when the flat bright pigment is iron oxide-coated flat aluminum particles or iron oxide-coated flat silicon dioxide particles (including both), "100 parts by mass of aluminum element or silicon element in the flat bright pigment" is to be read as "100 parts by mass of the total of aluminum element and silicon element in the flat bright pigment." If the amount of iron element exceeds 400 parts by mass, the degree of coverage with iron oxide becomes excessively high, the shape of the flat bright pigment changes from a flat shape, and changes in hue and brightness become difficult to occur. On the other hand, if the amount of iron element is less than 5 parts by mass, the mechanical strength of the flat bright pigment is insufficient, and the pigment is prone to cracking during fiber molding.

[0021] The ratio of the content of aluminum element (Al) or silicon element (Si) to the content of iron element (Fe) in the flat bright pigment can be calculated using an energy dispersive X-ray fluorescence analyzer. Specifically, C (carbon) is set as the balance element (component), and the content of aluminum element and iron element, or silicon element and iron element, can be quantified by quantitative analysis using the fundamental parameter method (FP method). Note that, as the energy dispersive X-ray fluorescence analyzer, for example, an EDX-720 manufactured by Shimadzu Corporation can be used.

[0022] The iron oxide-coated flat aluminum particles according to this embodiment may have a reflective layer containing silicon dioxide between the flat aluminum particles and the iron oxide layer. By providing the reflective layer, light incident on the flat surfaces of the iron oxide-coated flat aluminum particles from a certain direction is reflected in a certain regular reflection direction from the iron oxide layer surface (particle surface), the interface between the iron oxide layer and the reflective layer, and the interface between the reflective layer and the substrate (flat aluminum particles). However, the light reflected from the particle surface, the light reflected from the interface between the iron oxide layer and the reflective layer, and the light reflected from the interface between the reflective layer and the substrate interfere with each other. This enhances the changes in hue and brightness, resulting in a glittering fiber with better polarization.

[0023] The degree of coverage of the aluminum particles with the reflective layer is determined by the ratio of the amount of elements (i.e., silicon element) constituting the reflective layer in the flat bright pigment to the amount of aluminum element in the flat bright pigment. When the flat bright pigment according to this embodiment is an iron oxide-coated flat aluminum particle and has a reflective layer, the amount of silicon element in the flat bright pigment is preferably 5 to 50 parts by mass, more preferably 8 to 40 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of aluminum element in the flat bright pigment. If the amount of silicon element exceeds 50 parts by mass, the degree of coverage with the reflective layer becomes excessive, which may impair light reflectivity. On the other hand, if the amount of silicon element is less than 5 parts by mass, the effect of enhancing changes in hue and brightness is poor.

[0024] The ratio of the aluminum element (Al) to the silicon element (Si) content in the flat bright pigment can be calculated using an energy dispersive X-ray fluorescence analyzer (manufactured by Shimadzu Corporation, product name: EDX-720). Specifically, the aluminum element and silicon element contents can be quantified by quantitative analysis using the fundamental parameter method (FP method), with C (carbon) set as the balance element (component).

[0025] When the flat bright pigment according to this embodiment has a reflective layer, the aluminum particles have a structure in which at least a portion (all or a part) of the aluminum particles are coated with silicon dioxide. From the viewpoint of achieving uniform hue and brightness of the fiber, it is preferable that the entire surfaces of the aluminum particles are coated with silicon dioxide.

[0026] The average particle size of the flat bright pigment according to this embodiment is not particularly limited, but is preferably 1 to 70 μm, more preferably 5 to 40 μm, and even more preferably 10 to 20 μm. When the average particle size is within the above range, the flat bright pigment is more likely to satisfy the aspect ratio described below, is less likely to crack during fiber molding, and is more likely to maintain its flat shape.

[0027] The average particle diameter of a flat luster pigment can be measured by observation using a scanning electron microscope (SEM). For example, the surfaces of 50 randomly selected flat luster pigments are observed using a scanning electron microscope, and the maximum diameter of each pigment is taken as the particle diameter of the flat luster pigment. If a portion of the pigment is melted or connected to itself, the portion corresponding to the pigment before melting or bonding is identified, and this is approximately considered to be the pigment, and the particle diameter (maximum particle diameter) is measured. The arithmetic mean value of the particle diameters of the 50 flat luster pigments is then calculated and used as the average particle diameter. The maximum diameter of a flat luster pigment can be calculated using image analysis software or an SEM image. When calculating the maximum diameter from an SEM image, a line is drawn connecting any two points on the periphery of the pigment in the SEM image so that the line length is maximized, and the length of the line is measured and used as the maximum diameter.

[0028] The average thickness of the flat bright pigment is not particularly limited, but is preferably 1 to 3,500 nm, more preferably 1 to 2,000 nm, and even more preferably 2 to 1,000 nm. When the average thickness is within the above range, the color and metallic appearance of the pigment are less likely to be visually recognized when the flat bright pigment is observed from the side and / or from an oblique direction, and the mechanical strength of the flat bright pigment can be increased.

[0029] The average thickness of the flat bright pigment can be measured by observation using a transmission electron microscope (TEM). For example, the cross sections of 20 randomly selected flat bright pigments are observed using a transmission electron microscope, and the thickness of each pigment is measured. The arithmetic mean value of the thicknesses of the 20 flat bright pigments is then calculated to be the average thickness. The thickness of the flat bright pigment can be calculated using image analysis software or TEM images.

[0030] The average particle size relative to the average thickness of the flat bright pigment, i.e., the aspect ratio (average particle size / average thickness), is not particularly limited, but is preferably 20 to 5,000, more preferably 25 to 3,000, and even more preferably 30 to 2,000. When the aspect ratio is within the above range, the hue and brightness tend to change more significantly, and the flat bright pigment becomes easier to handle. Note that in this embodiment, the "flat" particles may have, for example, a ratio of particle size to thickness (particle size / thickness) of 2 or more.

[0031] The blending ratio of the flat bright pigment to the total mass of the bright fiber according to this embodiment is not particularly limited. The flat bright pigment is blended in an amount of preferably 0.05 to 3 mass%, more preferably 0.05 to 2 mass%, and even more preferably 0.1 to 1.5 mass%, relative to the total mass of the bright fiber. When the blending ratio of the flat bright pigment is within the above range, changes in hue and brightness of the fiber are more likely to occur.

[0032] The method for producing the flat luster pigment is not particularly limited, and examples include a method for forming a coating of iron oxide on the surface of flat aluminum particles or flat silicon dioxide particles by chemical vapor deposition, and a method for forming a coating of iron oxide by wet chemical deposition. When using chemical vapor deposition, for example, a coating of iron oxide can be formed on the particle surface by oxidatively decomposing iron carbonyl in the gas phase in the presence of flat aluminum particles or flat silicon dioxide particles. When using wet chemical deposition, for example, a coating of iron oxide can be formed on the particle surface by dispersing flat aluminum particles or flat silicon dioxide particles in a solvent and hydrolyzing an iron compound in the solution. Examples of iron compounds used in wet chemical deposition include inorganic salts such as iron nitrate, iron sulfate, and iron chloride; and organic salts such as iron acetate, iron formate, iron citrate, iron acetylacetonate, and ferrocene. The thickness of the iron oxide layer and the color of the flat luster pigment can be adjusted by adjusting the amount of iron compound added and / or the reaction time. In addition, when aluminum particles are used, a passivation layer may be formed on the surface of the aluminum particles before coating them with iron oxide in either method. The wet chemical method is preferred as a production method because it allows the formation of an iron oxide layer with a uniform thickness and is less likely to cause uneven color and brightness.

[0033] When the flat bright pigment has a reflective layer, the manufacturing method is not particularly limited, and examples include a method in which a reflective layer and an iron oxide layer are formed by a wet chemical method. When forming the reflective layer by a wet chemical method, for example, a reflective layer can be formed on the particle surface by dispersing flat aluminum particles in a solvent, adding an organosilicon compound to the solution, and performing hydrolysis and polycondensation. The organosilicon compound may be any compound that converts to silicon dioxide upon hydrolysis and polycondensation, such as tetraalkoxysilane. Preferably, each alkoxy group in the tetraalkoxysilane has 1 to 4 carbon atoms, such as tetraethoxysilane. Furthermore, the hydrolysis and polycondensation of the organosilicon compound are preferably carried out in the presence of a catalyst such as a base or an acid. Examples of catalysts include sodium hydroxide solution, aqueous ammonia, phosphoric acid, acetic acid, and oxalic acid. The thickness of the reflective layer can be adjusted by the amount of organosilicon compound added and / or the reaction time.

[0034] When forming the iron oxide layer by a wet chemical method, for example, aluminum particles coated with a reflective layer are dispersed in a solvent, and an iron compound is added to the solution and hydrolyzed to form the iron oxide layer on the surface of the reflective layer. Examples of iron compounds include inorganic salts such as iron nitrate, iron sulfate, and iron chloride; and organic salts such as iron acetate, iron formate, iron citrate, iron acetylacetonate, and ferrocene. The thickness of the iron oxide layer and the color of the flat bright pigment can be adjusted by adjusting the amount of iron compound added and / or the reaction time.

[0035] The glittering fiber according to this embodiment contains a coloring pigment. The coloring pigment is a pigment for coloring the glittering fiber, and its color is appropriately selected depending on the color of the flat glittering pigment. Examples of the coloring pigment include organic pigments and inorganic pigments, and one or more types can be used in combination.

[0036] Examples of organic pigments include azo pigments, benzimidazolone pigments, β-naphthol pigments, naphthol AS pigments, condensed azo pigments, quinacridone pigments, perylene pigments, perinone pigments, isoindolinone pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, diketopyrrolopyrrole (DPP) pigments, and phthalocyanine pigments.

[0037] Examples of inorganic pigments include compounds such as oxides, hydroxides, sulfides, silicates, and ferrocyanides of metals selected from the group consisting of titanium, zinc, chromium, iron, cobalt, copper, manganese, magnesium, bismuth, yttrium, aluminum, and vanadium; red iron oxide; and red iron oxide. The inorganic pigment may be a compound containing one or more of the above metals. Examples of composite compounds include Fe-Co-Cr, Cu-Cr, Fe-Cr, Fe-Mn, Cu-Mn, Cu-Mg, Cu-Bi, Mn-Bi, Y-Mn, Co-Al, and Fe-Co-Al-Mg salts. Among these, pigments that exhibit colors not found in organic pigments are preferred, and white pigments such as titanium oxide, aluminum oxide, and zinc oxide are more preferred.

[0038] Among organic and inorganic pigments, organic pigments are preferred because they can greatly change the hue of the glittering fiber. Furthermore, the flat glittering pigment of this embodiment exhibits a color ranging from yellow to red depending on the amount of iron oxide coated. Because they can greatly change the hue of the glittering fiber, a color that is complementary to the color of the flat glittering pigment is preferred as the coloring pigment. Examples of complementary colors include blue, green, blue-green, purple, and blue-purple, with blue being preferred among these. In other words, the coloring pigment preferably includes a blue pigment.

[0039] Examples of blue pigments include organic pigments such as phthalocyanine pigments, quinacridone pigments, dioxazine pigments, and perylene pigments; and inorganic pigments such as composite oxides such as bismuth vanadium oxide and cobalt blue. Among these, from the viewpoints of colorability and transparency, phthalocyanine pigments are preferred, and phthalocyanine blue is more preferred. The blue pigments can be used alone or in combination of two or more.

[0040] The average particle size of the color pigment according to this embodiment is not particularly limited, but is preferably 0.01 to 2 μm, more preferably 0.02 to 1.5 μm, and even more preferably 0.05 to 1 μm. By having the average particle size within the above range, the color and brilliance derived from the flat bright pigment are less likely to be impaired, and it becomes easier to increase the change in hue exhibited by the bright fiber.

[0041] The average particle size of the color pigment can be measured by observation using a transmission electron microscope (TEM). For example, 50 randomly selected color pigments are observed using a transmission electron microscope, and the maximum diameter of each pigment is taken as the particle size of the color pigment. The arithmetic mean value of the particle sizes of the 50 color pigments is then calculated as the average particle size. The maximum diameter of the color pigment can be calculated using image analysis software or a TEM image. When calculating the maximum diameter from a TEM image, the same method as used to determine the maximum diameter of the aforementioned flat luster pigment from an SEM image can be used.

[0042] The blending ratio of the color pigment to the total mass of the glittering fiber according to this embodiment is not particularly limited, but is preferably in the range of 0.01 to 1 mass%, more preferably 0.02 to 0.5 mass%, and even more preferably 0.03 to 0.35 mass%. When the blending ratio of the color pigment is within the above range, changes in hue and brightness in the fiber are more likely to occur.

[0043] The blending ratio of the color pigment to the flat luster pigment is not particularly limited, but the amount of the color pigment is preferably 1 to 130 parts by mass, more preferably 2 to 120 parts by mass, and even more preferably 4 to 110 parts by mass, per 100 parts by mass of the flat luster pigment. If the amount of the color pigment exceeds 130 parts by mass, the color and luster derived from the flat luster pigment are likely to be impaired. On the other hand, if the amount of the color pigment is less than 1 part by mass, the color derived from the color pigment is difficult to visually recognize.

[0044] The glittering fiber according to this embodiment contains a resin. The resin serves to form the fiber or molded articles such as colored pellets, colored flakes, colored chips, and masterbatches, which will be described later. The resin may be selected from polyolefin, polyamide, polyester, acrylonitrile resin, polyvinyl chloride, polyvinylidene chloride, and vinyl chloride-vinylidene chloride copolymer resin.

[0045] Examples of polyolefins include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, polypropylene-ethylene copolymer, polybutene, polyisobutylene, polybutadiene, polymethylpentene, ethylene-propylene rubber, etc. Examples of polyamides include nylon 6, nylon 6,6, nylon 6,9, nylon 6,10, nylon 11, nylon 12, 6-11 copolymer nylon, 6-12 copolymer nylon, 6,9-12 copolymer nylon, 6-6,6-12 terpolymer nylon, amorphous polyamide, polyamide elastomer, etc. Examples of polyesters include polyhexamethylene terephthalate, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, saturated aliphatic polyester, polyester elastomer, polylactic acid, polycaprolactone, polyglycolic acid, polybutylene succinate, etc. Examples of acrylonitrile resins include polyacrylonitrile, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), acrylonitrile-styrene copolymer resin (AS resin), etc. These resins can be used alone or in combination of two or more.

[0046] Among these, polyolefins are preferred from the viewpoints of fiber spinnability, cost, and fiber strength, and polypropylene-ethylene copolymers are more preferred because they can easily impart flexibility.

[0047] The glittering fiber according to this embodiment can be obtained by molding a resin composition prepared by melt-kneading a flat glittering pigment, a coloring pigment, and a resin. The method for producing such a resin composition is not particularly limited as long as it allows the flat glittering pigment and coloring pigment to be uniformly dispersed in the resin. For example, the flat glittering pigment and coloring pigment may be mixed with a pre-molten resin. Furthermore, to uniformly disperse the flat glittering pigment and coloring pigment when producing the resin composition, a frozen and crushed resin may be used, or a powdered resin that is compatible with the resin may be used together with the resin.

[0048] The method for melt-kneading is not particularly limited, and a known kneader can be used. Examples of kneaders include a Henschel mixer, a three-roll mill, a two-roll mill, and an extruder. In this embodiment, a flat luster pigment coated with iron oxide is used, so that the flat luster pigment is less likely to be damaged even when a high shear force is applied during melt-kneading. Examples of devices for melt-kneading at a high shear force include extruders such as a single-screw extruder and a twin-screw extruder.

[0049] The resin composition described above may be molded as is into a glittering fiber, or may be pelletized, flaked, or chipped into a colored molded body such as colored pellets, colored flakes, or colored chips, and then the colored molded body may be melt-kneaded and molded into a glittering fiber. In colored molded bodies such as colored pellets, colored flakes, and colored chips, the flat glittering pigment and the colored pigment are blended at the same concentrations as in the glittering fiber, and are used without being diluted with another resin.

[0050] Alternatively, the resin composition may be pelletized, flaked, or chipped to form a masterbatch, which may then be melt-kneaded and molded with another resin (hereinafter sometimes referred to as a "base resin") so that the flat bright pigment and color pigment have a desired concentration, to form a bright fiber. Note that a masterbatch is a colored molded product in which the flat bright pigment and color pigment are dispersed at a high concentration in a resin, and is used by diluting it with a base resin.

[0051] The method for pelletizing, flaking, or chipping the resin composition is not particularly limited, and any known method can be used.

[0052] The base resin used to dilute the masterbatch may be the same as or different from the resin contained in the masterbatch, but from the viewpoint of compatibility between the masterbatch and the base resin, it is preferable that the base resin be the same resin.

[0053] The method for diluting the masterbatch with the base resin is not particularly limited. For example, the masterbatch and the base resin are dry-mixed and then melt-kneaded, or the masterbatch is added to the molten base resin and then melt-kneaded. The kneader for melt-kneading may be the same as the kneader described above.

[0054] The resin composition containing the flat bright pigment, color pigment, and resin may further contain an amino group-containing thermoplastic resin to provide the presence of amino groups, thereby enhancing the polarizing properties.

[0055] The amino group-containing thermoplastic resin may be any polymer having a structural unit derived from an amino group-containing monomer, and one or more of them may be used in combination. Amino group-containing (meth)acrylic resins are preferred because they can further enhance the polarization properties. Note that the term "(meth)acrylic resin" includes both acrylic resins and methacrylic resins, and the (meth)acrylic resin is a polymer containing a structural unit derived from a (meth)acryloyl group-containing monomer, and the (meth)acryloyl group is an acryloyl group (CH ２ =CH-COO-) or a methacryloyl group [CH２ =C(-CH ３ )-COO-]. Therefore, the amino group-containing (meth)acrylic resin is a polymer containing structural units derived from a (meth)acryloyl group-containing monomer that contains an amino group. The amino group-containing (meth)acrylic resin can be used alone or in combination of two or more types.

[0056] Examples of the (meth)acryloyl group-containing monomer containing an amino group that constitutes the amino group-containing (meth)acrylic resin include aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, methylaminoethyl (meth)acrylate, ethylaminoethyl (meth)acrylate, butylaminoethyl (meth)acrylate, methylaminopropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dibutylaminoethyl (meth)acrylate, etc. Among these, dimethylaminoethyl (meth)acrylate is preferred because it is easy to further enhance the polarizing properties.

[0057] The amino group-containing (meth)acrylic resin may contain, in addition to the structural units derived from the (meth)acryloyl group-containing monomer containing an amino group, structural units derived from (meth)acrylic acid and / or structural units derived from a (meth)acrylic acid ester. Examples of (meth)acrylic acid include acrylic acid and methacrylic acid. Examples of (meth)acrylic acid ester include methyl methacrylate, ethyl acrylate, propyl acrylate, and butyl methacrylate.

[0058] The amino group-containing (meth)acrylic resin can be produced by a known polymerization method. Radical polymerization is a common polymerization method. Examples of initiators that can be used for radical polymerization include azo initiators, peroxide initiators, and redox initiators. Among these, azo initiators are preferred, and 2,2'-azobis(2-methylbutyronitrile) is more preferred.

[0059] Furthermore, a resin composition containing a flat luster pigment, a color pigment, and a resin may contain an amino group by blending an amino group-containing dispersant. In this case, from the viewpoint of the manufacturing process, it is preferable to contain the above-mentioned amino group-containing thermoplastic resin or non-amino group-containing thermoplastic resin. Note that these thermoplastic resins are different from the resins constituting the above-mentioned resin composition.

[0060] As the amino group-containing dispersant, trialkylamines such as trimethylamine, triethylamine, and tributylamine; and alkylolaminoamides are preferred, since they can further enhance the polarizing properties.

[0061] The non-amino group-containing thermoplastic resin may be a resin selected from the group consisting of hydroxyl group-containing resins, polyolefins, polyamides, polyesters, polycarbonates, polyimides, polyamideimides, polyarylates, vinyl polymers, cellulose resins, engineering plastics, and fluororesins.

[0062] Examples of hydroxyl group-containing resins include hydroxyl group-containing (meth)acrylic resins, etc.; Examples of polyolefins include polyethylene, polypropylene, polybutene, poly(4-methylpentene), etc.; Examples of polyamides include 6-nylon, 6,6-nylon, amorphous polyamide, etc.; Examples of polyesters include alkyd resins, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polylactic acid, polycaprolactone, polyglycolic acid, polybutylene succinate, etc.; Examples of polyimides include aromatic polyimides, etc.; Examples of polyarylates include amorphous polyarylates, etc.; Examples of vinyl polymers include polystyrene, polyvinyl chloride, polymethyl methacrylate, polyvinyl acetate, polyacrylonitrile, acrylonitrile-butadiene-styrene (ABS) copolymer resin, acrylonitrile-styrene (AS) copolymer resin, etc.; Examples of cellulose resins include cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, nitrocellulose, etc. Examples of engineering plastics include polysulfone, polyether sulfone, polyacetal, polyether ether ketone, polyether ketone, polyketone, polyphenylene sulfide, etc. Examples of fluororesins include polytetrafluoroethylene, etc. These non-amino group-containing thermoplastic resins can be used alone or in combination of two or more.

[0063] The hydroxyl group-containing resin may be any polymer having a structural unit derived from a hydroxyl group-containing monomer, and one or more of them may be used in combination. Hydroxyl group-containing (meth)acrylic resins are preferred because they can further enhance the polarization properties. Note that the term "(meth)acrylic resin" includes both acrylic resins and methacrylic resins, and the (meth)acrylic resin is a polymer containing a structural unit derived from a (meth)acryloyl group-containing monomer, and the (meth)acryloyl group is an acryloyl group (CH ２ =CH-COO-) or a methacryloyl group [CH ２ =C(-CH ３)-COO-]. Therefore, a hydroxyl group-containing (meth)acrylic resin is a polymer containing structural units derived from a (meth)acryloyl group-containing monomer that contains a hydroxyl group. The hydroxyl group-containing (meth)acrylic resin can be used alone or in combination of two or more types.

[0064] Among non-amino group-containing thermoplastic resins, resins selected from hydroxyl group-containing resins, polyolefins, polyesters, polycarbonates, (meth)acrylic resins, acrylonitrile-butadiene-styrene (ABS) copolymer resins, and cellulose resins are preferred because they make it easier to further enhance the polarizing properties; resins selected from hydroxyl group-containing resins, polyolefins, alkyd resins, polycarbonates, (meth)acrylic resins, acrylonitrile-butadiene-styrene (ABS) copolymer resins, and cellulose acetate butyrate are more preferred; resins selected from hydroxyl group-containing resins, polyolefins, polycarbonates, and (meth)acrylic resins are even more preferred; and hydroxyl group-containing (meth)acrylic resins or hydroxyl group-containing (meth)acrylic esters are particularly preferred.

[0065] The photochromic fiber of this embodiment may also contain a color-changing material such as a thermochromic material and / or a photochromic material, which allows the photochromic fiber to change color, for example, in response to a temperature change and / or light irradiation.

[0066] Examples of thermochromic materials include a thermochromic composition consisting of at least (i) an electron-donating color-forming organic compound and (ii) an electron-accepting compound, and a thermochromic composition (reversible thermochromic composition) consisting of at least the component (i), the component (ii), and (iii) a reaction medium that determines the temperature at which the color reaction of the components (i) and (ii) occurs.

[0067] Examples of reversible thermochromic compositions that can be used include heat-discolorable reversible thermochromic compositions having a relatively small hysteresis width (ΔH) (ΔH = 1 to 7°C), as described in Japanese Patent Publication Nos. 51-44706, 51-44707, and 1-29398. "Heat-discolorable" refers to a composition that discolors upon heating and develops color upon cooling. These reversible thermochromic compositions undergo color changes across a predetermined temperature (color change point), exhibiting a discolored state in a temperature range above the high-temperature color change point and a colored state in a temperature range below the low-temperature color change point. Only one of these two states exists at room temperature, and the other state is maintained while the heat or cold required to achieve that state is applied, but returns to the state it exhibits at room temperature once the application of heat or cold is removed.

[0068] The reversible thermochromic composition may be a heat-discolorable reversible thermochromic composition having a large hysteresis width (ΔH = 8 to 80°C) as described in, for example, JP-B No. 4-17154, JP-A No. 7-179777, JP-A No. 7-33997, JP-A No. 8-39936, or JP-A No. 2005-1369. "Heat-discolorable" means that the composition discolors upon heating and develops color upon cooling. This reversible thermochromic composition exhibits a change in color density with temperature that follows a significantly different path when the temperature is increased from a temperature lower than the color-change temperature range, and when the temperature is decreased from a temperature higher than the color-change temperature range. The temperature-discolorable reversible thermochromic composition reaches a temperature at which the composition completely develops color (t １ Coloring state in the following temperature range, or complete decolorization temperature t ４ The color disappears in the above high temperature range. ２ ~Discoloration start temperature t ３ It has color memory in the temperature range between (substantially two-phase maintaining temperature range).

[0069] The reversible thermochromic composition may be a heat-coloring type reversible thermochromic composition using a gallic acid ester, as described in JP-B No. 51-44706, JP-A No. 2003-253149, etc. The heat-coloring type means that the color develops when heated and disappears when cooled.

[0070] The reversible thermochromic composition is a compatible solution containing the above-mentioned components (A), (B), and (C) as essential components, and the proportions of each component depend on the concentration, color change temperature, color change form, and type of each component. Generally, the component ratios that provide desired properties are in the range of 1 part of component (A) to 0.1 to 100, preferably 0.1 to 50, more preferably 0.5 to 20, of component (B), and 1 to 800, preferably 5 to 200, more preferably 5 to 100, and even more preferably 10 to 100, of component (C) (all of the above proportions are in parts by mass).

[0071] Examples of photochromic materials include conventionally known photochromic compounds such as spirooxazine derivatives, spiropyran derivatives, and naphthopyran derivatives, which develop color when irradiated with sunlight, ultraviolet light, or blue light having a peak emission wavelength in the range of 400 to 495 nm and lose color when the irradiation is stopped. Examples include compounds described in JP 2021-120493 A and WO 2020 / 137469 A. Furthermore, photochromic compounds having photomemory properties (color memory photochromic properties) can also be used. Examples of such photochromic compounds include diarylethene derivatives, such as the compounds described in JP 2021-120493 A.

[0072] The photochromic material may be a photochromic composition (reversible photochromic composition) comprising at least the above-mentioned photochromic compound and an oligomer, such as a styrene-based oligomer, an acrylic-based oligomer, a terpene-based oligomer, or a terpene-phenol-based oligomer.

[0073] The reversible thermochromic composition or reversible photochromic composition can be encapsulated in microcapsules to form a reversible thermochromic microcapsule pigment or reversible photochromic microcapsule pigment (hereinafter sometimes referred to as a "microcapsule pigment"), or dispersed in a thermoplastic resin or thermosetting resin to form reversible thermochromic resin particles or reversible photochromic resin particles, and used as a reversible thermochromic material or reversible photochromic material. The reversible thermochromic composition or reversible photochromic composition is preferably encapsulated in microcapsules and used as a microcapsule pigment. This is because encapsulation in microcapsules allows for the formation of a chemically and physically stable pigment, and the reversible thermochromic composition or reversible photochromic composition can maintain the same composition and exhibit the same effects under various usage conditions.

[0074] Microencapsulation may be carried out by known methods such as an isocyanate-based interfacial polymerization method, an in situ polymerization method such as a melamine-formalin-based method, a liquid curing coating method, a phase separation method from an aqueous solution, a phase separation method from an organic solvent, a melting dispersion cooling method, an air suspension coating method, and a spray drying method, and is appropriately selected depending on the application.

[0075] Depending on the purpose, a secondary resin film may be provided on the surface of the microcapsules to impart durability or to modify the surface properties for practical use.

[0076] The reversible thermochromic microcapsule pigment or reversible photochromic microcapsule pigment preferably has a mass ratio of inclusions to wall film of 7:1 to 1:1, and by having the mass ratio of inclusions to wall film within the above range, it is possible to prevent a decrease in color density and clarity during color development. More preferably, the mass ratio of inclusions to wall film is 6:1 to 1:1.

[0077] When a reversible thermochromic microencapsulated pigment or a reversible photochromic microencapsulated pigment is used as the color-changing material, the average particle size of these microencapsulated pigments is not particularly limited, but is preferably 0.1 to 30 μm, more preferably 0.5 to 20 μm, and even more preferably 0.5 to 10 μm. If the average particle size exceeds 30 μm, dispersion stability and processability tend to be lacking when blended into a resin. On the other hand, if the average particle size is less than 0.1 μm, it becomes difficult to exhibit high-concentration color development.

[0078] The average particle diameter of the microcapsule pigment is determined by using image analysis particle size distribution measurement software (manufactured by Mountec Co., Ltd., product name: MacView) to determine the particle region, calculating the projected area circle equivalent diameter (Heywood diameter) from the area of ​​the particle region, and measuring the average particle diameter (D50) of particles equivalent to an equivalent volume sphere using this value. Furthermore, when the particle diameter of all or most of the particles exceeds 0.2 μm, it is also possible to measure the average particle diameter of particles equivalent to an equivalent volume sphere by the Coulter method using a particle size distribution measurement device (manufactured by Beckman Coulter, Inc., product name: Multisizer 4e). Furthermore, the volume-based particle diameter and average particle diameter may be measured using a calibrated laser diffraction / scattering particle size distribution measurement device (manufactured by Horiba, Ltd., product name: LA-300) based on the values ​​measured using the above software or a measurement device using the Coulter method.

[0079] The blending ratio of the color-changing material to the total mass of the photoluminescent fiber according to this embodiment is not particularly limited, but is preferably 0.1 to 10 mass%, more preferably 0.5 to 7 mass%. By blending the color-changing material in this range, the dispersion stability of the color-changing material in the resin is good, and it becomes easy to obtain a photoluminescent fiber that changes color in response to temperature changes and / or light irradiation without impairing the photoluminescence and polarization properties of the fiber.

[0080] The glittering fiber according to this embodiment can also contain various additives as needed. Examples of additives include flame retardants, dispersants, light stabilizers, fluorescent whitening agents, surfactants, antistatic agents, water repellents, mildew inhibitors, insect repellents, plasticizers, and lubricants. Furthermore, calcium carbonate, magnesium carbonate, talc, and the like can be added to improve processability and physical properties. Examples of dispersants include waxes, such as paraffin wax, microcrystalline wax, montan wax, polyethylene wax, polypropylene wax, polystyrene wax, low-molecular-weight polybutene, liquid polybutadiene, liquid polypentadiene, oligoester acrylate, polyamide oligomer, polyester oligomer, tetrafluoroethylene wax, perfluoropolyether, perfluoroolefin oligomer, and silicone oligomer. Examples of light stabilizers include ultraviolet absorbers, antioxidants, antiaging agents, singlet oxygen quenchers, ozone quenchers, superoxide anion quenchers, ozone quenchers, visible light absorbers, and infrared absorbers.

[0081] The glittering fiber according to this embodiment can be obtained by melt spinning using a melt spinning apparatus or the like, and is produced in the form of a monofilament or multifilament. Specific examples of the monofilament or multifilament form include single fibers formed from one type of resin composition and composite fibers formed from two or more types of resin compositions. Examples of composite fiber forms include sheath-core, side-by-side, split, and sea-island. In the sheath-core form, the core primarily maintains the fiber shape, while the sheath primarily protects the core and provides strength to the fiber. The structure shows a structure in which at least a portion (partial or all) of the periphery of the core is covered by the sheath. An additional intermediate layer can also be provided between the core and sheath. Such an intermediate layer can have functions such as improving adhesion between the core and sheath and preventing peeling. Furthermore, an intermediate layer having a composition intermediate between the sheath and core can be provided, thereby allowing the composition to change gradually from the center of the fiber to the periphery.

[0082] The glittering fiber according to this embodiment may be either a monofilament or a composite fiber. In the case of a composite fiber, it is preferably a sheath-core type from the viewpoint of fiber durability, and more preferably a structure in which the entire periphery of the core is covered by the sheath. Furthermore, in the case of a sheath-core type, the area ratio of the core to the sheath in the cross section of the composite fiber is preferably 4:6 to 7:3. By having this area ratio within the above range, a composite fiber with excellent fiber strength and texture can be constructed. More preferably, the area ratio of the core to the sheath is 5:5 to 6:4. Note that, when observing the cross section of the composite fiber, the core and sheath do not necessarily have to be arranged concentrically (a concentric sheath-core type), and a heterocentric sheath-core type in which the centers of the core and sheath are different can also be used. Examples of the cross-sectional shape of the fiber include circular shapes such as a perfect circle or an ellipse; polygonal shapes such as a trilobal, triangular, rectangular, pentagonal, or star; and Y-shaped shapes. However, from the viewpoint of spinnability and processability, a circular cross-sectional shape is preferred.

[0083] When the photoluminescent fiber according to this embodiment is a core-sheath composite fiber, it can be configured such that both the flat photoluminescent pigment and the coloring pigment are contained in the core or the sheath. Alternatively, it can be configured such that one is contained in the core and the other in the sheath. For example, it can be configured such that the coloring pigment is contained in the core and the flat photoluminescent pigment is contained in the sheath. When a color-changing material is further incorporated, it can be configured such that the core contains a flat photoluminescent pigment, a coloring pigment, and a color-changing material; a coloring pigment and a color-changing material in the core and a flat photoluminescent pigment in the sheath; or a color-changing material in the core and a flat photoluminescent pigment and a coloring pigment in the sheath.

[0084] When the shiny fiber according to this embodiment is a core-sheath type composite fiber, the resin constituting the core and the resin constituting the sheath are thermoplastic resins, and the above-mentioned polyolefin, polyamide, polyester, acrylonitrile resin, polyvinyl chloride, polyvinylidene chloride, and vinyl chloride-vinylidene chloride copolymer resins can be used.

[0085] The resins constituting the core and sheath may be the same or different. When the resins constituting the core and sheath are the same, excellent adhesion between the core and sheath can be achieved, preventing delamination at the interface between the core and sheath. When the resins constituting the core and sheath are different, it is preferable to use a polyolefin as the resin constituting the core and a polyamide as the resin constituting the sheath. This increases the strength of the fiber while maintaining adhesion between the core and sheath, and further imparts excellent gloss and texture to the fiber. Suitable polyolefin resins include linear low-density polyethylene, polypropylene, and polypropylene-ethylene random copolymer. Suitable polyamide resins include nylon 6, 6,6 nylon, 6,9 nylon, 6,10 nylon, nylon 11, nylon 12, 6-11 copolymer nylon, 6-12 copolymer nylon, 6,9-12 copolymer nylon, 6-6,6-12 terpolymer nylon, and polyamide elastomer.

[0086] The average outer diameter of the glittering fiber according to this embodiment is not particularly limited, but is preferably 10 to 300 μm, more preferably 50 to 150 μm. If the average outer diameter exceeds 300 μm, the flexibility of the fiber is likely to be impaired. On the other hand, if the average outer diameter is less than 10 μm, it becomes difficult to increase the amount of flat glittering pigment and coloring pigment blended, and glitter and polarization properties are likely to be impaired. The average outer diameter corresponds to the arithmetic average of the outer diameters at multiple locations on a single fiber.

[0087] The outer diameter of the glittering fiber can be calculated, for example, using image analysis software or a planimeter based on a cross-sectional photograph of the fiber taken by an optical microscope or an electron microscope. If the cross-sectional shape of the fiber is not circular, the outer diameter is the diameter of the circle when the cross-sectional area is taken as the area of ​​the circle. When producing the glittering fiber using a melt spinning device, by appropriately adjusting conditions such as temperature and / or speed in the step of stretching the resin composition extruded from the spinneret, fibers having the desired outer diameter or average outer diameter can be obtained.

[0088] The average length of the glittering fiber according to this embodiment is not particularly limited, but is preferably 50 to 350 mm, and more preferably 100 to 300 mm. The average length corresponds to the arithmetic mean of the lengths of a plurality of fibers.

[0089] The photoluminescent fiber according to this embodiment can be used in toys, resulting in toys that have excellent photoluminescence and polarization. Examples of toys include, but are not limited to, doll toys or animal-shaped toys with hair or fur made of the photoluminescent fiber, stuffed toys with fur made of the photoluminescent fiber, and accessories for these. Examples of accessories include hair extensions for dolls. In particular, when the photoluminescent fiber according to this embodiment is used as toy hair, the curvature of the hair increases and the hue change becomes more pronounced. Therefore, toy hair and toys containing the same are suitable products using the photoluminescent fiber according to this embodiment, as they exhibit the effects of this embodiment more prominently.

[0090] The average outer diameter of the glittering fiber used in toys is not particularly limited, but is preferably in the range of 30 to 200 μm, more preferably 50 to 120 μm. If the average outer diameter exceeds 200 μm, the fiber will be too thick and will not easily exhibit hair properties. On the other hand, if the average outer diameter is less than 30 μm, the fiber will be prone to tangling and will be too flexible, which will likely impair the appearance of the product. The average length of the glittering fiber used in toys is not particularly limited, but is preferably 5 to 350 mm, more preferably 10 to 300 mm.

[0091] The glittering fiber according to this embodiment can be used for decorative articles, which have excellent glittering properties and polarizing properties. The decorative articles are not particularly limited, but examples thereof include false eyelashes, false beards, false eyebrows, hair wigs, and hair extensions.

[0092] The average outer diameter of the glittering fibers used in decorative articles is not particularly limited, but is preferably in the range of 30 to 200 μm, more preferably 60 to 150 μm. If the average outer diameter exceeds 200 μm, the fibers will be too thick and will tend to feel rough to the touch. On the other hand, if the average outer diameter is less than 30 μm, the fibers will tend to tangle and will be too flexible, which will tend to impair the texture. The average length of the glittering fibers used in decorative articles is not particularly limited, but is preferably 150 to 600 mm, more preferably 300 to 450 mm.

[0093] Further examples of products using the glittering fiber according to this embodiment include the following: (1) Clothing: Clothing such as T-shirts, shirts, sweatshirts, blouses, dresses, swimwear, raincoats, skiwear, etc.; footwear such as shoes and shoelaces; cloth accessories such as towels, handkerchiefs, and furoshiki wrapping cloths; gloves; ties; hats; ribbons; scarves; mufflers, etc. (2) Indoor decorations: Curtains, curtain strings, tablecloths, rugs, cushions, carpets, rugs, upholstery, seats, mats, etc. (3) Others: Calendars, cards, picture books, and other books, bags, fans, embroidery thread, straps, fishing tackle, coasters, wallets, and other bags, training equipment, etc.

[0094] Through research by the present inventors, it was found that in products using the photoluminescent fiber according to this embodiment, the absorption spectrum varies significantly between areas where the photoluminescent fiber is sparse and areas where it is dense. Specifically, it was found that the absorption spectrum A of the photoluminescent fiber measured after wrapping the photoluminescent fiber once around the substrate to cover at least a portion of the substrate, which is measured as a baseline in the absorption spectrum measurement, differs by 10 nm or more in one or more wavelengths selected from the group consisting of the first absorption maximum wavelength, the second absorption maximum wavelength, and the third absorption maximum wavelength between the photoluminescent fiber wrapped around the substrate four times. As a result, for example, in products containing photoluminescent fiber, the hue varies significantly between areas where the photoluminescent fiber is sparse and areas where it is dense. Here, the reason for measuring the absorption spectrum of the photoluminescent fiber after wrapping the photoluminescent fiber four times is that it is estimated that at least four fibers overlap in areas where the photoluminescent fiber is dense in products using the photoluminescent fiber. Specifically, to simulate a product using photoluminescent fiber, the photoluminescent fiber was wrapped around at least a portion of the substrate one or four times, and the absorption spectrum was measured. The "nth absorption maximum wavelength (n = 1, 2, 3)" refers to the wavelength at which the absorbance reaches its maximum value, and is the nth wavelength from the wavelength with the highest absorbance. The wavelength range of absorption spectra A and B covers the visible light region (400-800 nm). The difference between the nth absorption maximum wavelengths of absorption spectra A and B is preferably 20 nm or more, and even more preferably 40 nm or more. A standard white plate made of barium sulfate or fluororesin is generally used as the substrate used as the baseline in absorption spectrum measurement, but a resin substrate made of ABS may also be used. The thickness of the substrate may be, for example, 0.5-3 mm. The size (length, width) of the substrate is not particularly limited and can be selected appropriately depending on the length of the photoluminescent fiber, etc.

[0095] In products using the photoluminescent fiber of this embodiment, the greater the number of photoluminescent fibers, the more likely the photoluminescent fibers are to vary in density, resulting in changes in hue, and therefore the greater the design potential. The number of photoluminescent fibers in such products is preferably 10 or more, 50 or more, 100 or more, 500 or more, 1,000 or more, 5,000 or more, 10,000 or more, 50,000 or more, and 100,000 or more, in that order. Furthermore, in the case of artificial hair, a product using the photoluminescent fiber of this embodiment is preferably such that the photoluminescent fibers are more likely to vary in density from the root to the tip, resulting in changes in hue, and therefore the greater the design potential. Examples of artificial hair include any one or more selected from the group consisting of human hair, body hair, false eyelashes, false beards, false eyebrows, hair wigs, and hair extensions. Toys (doll toys, animal-shaped toys, etc.) or decorative items containing such artificial hair are also suitable.

[0096] Examples are shown below, but the present embodiment is not limited thereto. In the examples, "parts" refers to "parts by mass" unless otherwise specified.

[0097] The compositions of the glittering fibers of the examples and comparative examples are shown in the following Tables 1 and 2. The numerical values ​​of the compositions in the tables indicate parts by mass.

[0098]

[0099]

[0100] The contents of the materials in Tables 1 and 2 will be explained according to the note numbers. (1) Iron oxide-coated flaky aluminum particles (red, average particle diameter: 16 μm, average thickness: 300 nm, aspect ratio: 53, amount of iron element per 100 parts by mass of aluminum element: 160 parts by mass) (2) Iron oxide-coated flaky aluminum particles (orange, average particle diameter: 19 μm, average thickness: 170 nm, aspect ratio: 112, amount of iron element per 100 parts by mass of aluminum element: 24 parts by mass) (3) Iron oxide-coated flaky aluminum particles (light yellow, average particle diameter: 16 μm, average thickness: 140 nm, aspect ratio: 113, amount of iron element per 100 parts by mass of aluminum element: 10 parts by mass) (4) Iron oxide-coated flaky aluminum particles (dark red, average particle diameter: 16 μm, average thickness: 320 nm, aspect ratio: 50, amount of iron element per 100 parts by mass of aluminum element: 357 parts by mass) (5) Iron oxide-coated flat aluminum particles having a reflective layer containing silicon dioxide (red, average particle diameter: 23 μm, average thickness: 1000 nm, aspect ratio: 23, amount of silicon element per 100 parts by mass of aluminum element: 14 parts by mass, amount of iron element per 100 parts by mass of aluminum element: 157 parts by mass) (6) Iron oxide-coated flat silica flakes [manufactured by Merck Ltd., product name: Colorstream F10-51 Lava Red (red, particle diameter: 5 to 50 μm, aspect ratio: 19)] (7) Iron oxide-coated flat aluminum particles [manufactured by BASF, product name: Paliocrom Gold L2020 (gold, particle diameter: 8 to 38 μm, average particle diameter: 16 μm, aspect ratio: 107)] (8) Iron oxide-coated flat aluminum particles (reddish-brown, average particle diameter: 17 μm, average thickness: 350 nm, aspect ratio: 49, amount of iron element per 100 mass parts of aluminum element: 413 mass parts) (9) Iron oxide-coated flat aluminum particles [manufactured by BASF, product name: Paliocrom Sparkling Red L3505 (red, particle diameter: 13 to 31 μm, average particle diameter: 16 μm)] (10) Flat luster pigment in which the surface of natural mica is coated with titanium oxide and further coated with iron oxide [manufactured by Merck Ltd., product name: Iriodin 300 (gold, particle diameter: 10 to 60 μm)] (11) Colored aluminum pigment [manufactured by Toyo Aluminum K.K., product name;Friend Color D111 RE (solid content: 55%) (red, average particle size: 26 μm, average thickness: 140 nm, aspect ratio: 13.1) (12) Aluminum pigment paste [manufactured by Toyo Aluminum Co., Ltd., product name: 6360NS (solid content: 70%) (average particle size: 10 μm, average thickness: 0.25 μm, aspect ratio: 40)] (13) Phthalocyanine blue [manufactured by DIC Corporation, product name: Fastogen Blue AE-8 (average particle size: 80 nm)] (14) Bismuth vanadium oxide [manufactured by Torrecid, product name: Ultramarine Blue AL32177 (average particle size: 1.1 μm)] (15) Titanium oxide [manufactured by Teika Co., Ltd., product name: MT-500SA (average primary particle diameter: 35 nm)] (16) Pink pigment [manufactured by Nippon Shokubai Co., Ltd., product name: Epocolor FP-1000N] (17) Reversible thermochromic microencapsulated pigment (18) Polypropylene-ethylene random copolymer (melting point: 135 ° C) (19) 6-12 copolymer nylon (melting point: 145 ° C) (20) 6-12 copolymer nylon (melting point: 145 ° C);

[0101] The average particle size, average thickness, and contents of aluminum, iron, and silicon in the flat bright pigments A to E and H were determined by the following methods.

[0102] [Measurement of Average Particle Diameter] The average particle diameter of the flat luster pigment was determined by randomly selecting 50 flat luster pigments using a scanning electron microscope (SEM), observing the surface of each pigment, and determining the maximum diameter of the flat luster pigment. If the flat luster pigment was partially melted or connected to other pigments, the portion corresponding to the pigment before melting or bonding was identified, and this was approximately considered to be the pigment to measure the particle diameter (maximum particle diameter). The arithmetic mean value of the particle diameters of these pigments was then calculated to determine the average particle diameter. The maximum particle diameter was determined by drawing a line connecting any two points on the periphery of the flat luster pigment in the SEM image, determining the point where the line length was longest, and measuring the length of the line at that point. This was then determined to be the maximum particle diameter of the flat luster pigment.

[0103] [Measurement of Average Thickness] The average thickness of the flat particle bright pigment was measured by observing 20 flat particle bright pigments at random using a transmission electron microscope (TEM), observing the cross section of each pigment, and measuring the thickness. The arithmetic mean value of the thicknesses of these pigments was then calculated, which was used as the average thickness.

[0104] [Measurement of the content of aluminum, iron, and silicon in the flat bright pigment] The content ratio of aluminum (Al) to iron (Fe), or the content ratio of aluminum (Al), iron (Fe), and silicon (Si) in the flat bright pigment was calculated using an energy dispersive X-ray fluorescence analyzer. Specifically, carbon was set as the balance element (component), and the content of aluminum, iron, and silicon was quantified by quantitative analysis using the fundamental parameter method (FP method).

[0105] The above-mentioned reversible thermochromic microcapsule pigment was prepared as follows. Preparation of reversible thermochromic microcapsule pigment A reversible thermochromic composition consisting of 3 parts of 2-anilino-3-methyl-6-dibutylaminofluoran as component (A), 5 parts of 2,2'-bis(4-hydroxyphenyl)hexafluoropropane as component (B), and 50 parts of cyclohexylmethyl stearate as component (C) was added to a mixed solution consisting of 35 parts of an aromatic isocyanate prepolymer as a wall film material and 40 parts of a cosolvent, and then emulsified and dispersed in an 8% aqueous polyvinyl alcohol solution. After continued stirring while heating, 2.5 parts of a water-soluble aliphatic modified amine was added and further stirring was continued to prepare a microcapsule dispersion. A reversible thermochromic microcapsule pigment with an average particle size of 8 μm was obtained from the above-mentioned microcapsule dispersion by centrifugation. The microcapsule pigment had a complete color development temperature t １ is 14℃, complete discoloration temperature t ４ The temperature was 38°C, and the color changed reversibly from black to colorless with temperature change.

[0106] Example 1 Flat-shaped bright pigment A, phthalocyanine blue (manufactured by DIC Corporation, product name: Fastogen Blue AE-8 (average particle size: 80 nm)), polypropylene-ethylene random copolymer (melting point: 135°C), and dispersant were melt-mixed at 200°C in an extruder in the amounts shown in Table 1 to obtain colored pellets. These colored pellets were fed into a general-purpose extruder, spun at 200°C, and stretched to obtain a bright fiber in the form of a monofilament having an average outer diameter of 100 μm.

[0107] Example 2 Colored pellets were obtained in the same manner as in Example 1, except that the color pigment was changed to bismuth vanadium oxide (manufactured by Torrecid, product name: Ultramarine Blue AL32177 (average particle diameter: 1.1 μm)) and the blending amounts were changed as shown in Table 1. The colored pellets were fed into a general-purpose extruder, spun at 200° C., and stretched to obtain a monofilament-type glittering fiber having an average outer diameter of 100 μm.

[0108] Example 3: Flat-shaped bright pigment A, phthalocyanine blue (manufactured by DIC Corporation, product name: Fastogen Blue AE-8 (average particle size: 80 nm)), the above-mentioned reversible thermochromic microencapsulated pigment, polypropylene-ethylene random copolymer (melting point: 135°C), and dispersant were melt-mixed in an extruder at 200°C in the amounts shown in Table 1 to obtain colored pellets. These colored pellets were fed into a general-purpose extruder, spun at 200°C, and stretched to obtain a bright fiber in the form of a monofilament having an average outer diameter of 100 μm.

[0109] Example 4 Flat bright pigment B, phthalocyanine blue [manufactured by DIC Corporation, product name: Fastogen Blue AE-8 (average particle size: 80 nm)], titanium oxide [manufactured by Teika Corporation, product name: MT-500SA (average primary particle size: 35 nm)], polypropylene-ethylene random copolymer (melting point: 135°C), and a dispersant were melt-mixed at 200°C in an extruder in the amounts shown in Table 1 to obtain colored pellets. These colored pellets were fed into a general-purpose extruder, spun at 200°C, and stretched to obtain a bright fiber in the form of a monofilament having an average outer diameter of 100 μm.

[0110] Examples 5 to 10: Colored pellets were obtained in the same manner as in Example 1, except that the materials and blending amounts were changed as shown in Table 1. These colored pellets were fed to a general-purpose extruder, spun at 200°C, and stretched to obtain monofilament-type glittering fibers having an average outer diameter of 100 μm.

[0111] Example 11: Flat-shaped bright pigment A, phthalocyanine blue (manufactured by DIC Corporation, product name: Fastogen Blue AE-8 (average particle size: 80 nm)), polypropylene-ethylene random copolymer (melting point: 135°C), and dispersant were melt-mixed in an extruder at 200°C in the amounts shown in Table 1 to obtain colored pellets for the core. The colored pellets for the core were fed to an extruder for forming the core, and 6-12 copolymer nylon (melting point: 145°C) was fed to an extruder for forming the sheath, and the mixture was spun at 200°C from 18 discharge holes using a composite fiber spinning device so that the core:sheath ratio was 6:4 (area ratio), to obtain a multifilament bright fiber (sheath-core type bright composite fiber) consisting of 18 single yarns and having an average outer diameter of 100 μm.

[0112] Example 12: Flat-shaped bright pigment A, phthalocyanine blue (manufactured by DIC Corporation, product name: Fastogen Blue AE-8 (average particle size: 80 nm)), the above-mentioned reversible thermochromic microencapsulated pigment, polypropylene-ethylene random copolymer (melting point: 135°C), and dispersant were melt-mixed in an extruder at 200°C in the amounts shown in Table 1 to obtain colored pellets for the core. The colored pellets for the core were fed to an extruder for forming the core, and 6-12 copolymer nylon (melting point: 145°C) was fed to an extruder for forming the sheath, and the mixture was spun at 200°C from 18 nozzles using a composite fiber spinning device so that the core:sheath ratio was 6:4 (area ratio), to obtain a multifilament bright fiber (sheath-core type bright composite fiber) consisting of 18 single yarns and having an average outer diameter of 100 μm.

[0113] Example 13: Flat-shaped bright pigment I, a pink fluorescent pigment (manufactured by Nippon Shokubai Co., Ltd., product name: Epocolor FP-1000N), a polypropylene-ethylene random copolymer (melting point: 135°C), and a dispersant were melt-mixed in an extruder at 200°C in the amounts shown in Table 1 to obtain colored pellets for the core. The colored pellets for the core were fed to an extruder for forming the core, and 6-12 copolymer nylon (melting point: 145°C) was fed to an extruder for forming the sheath, and the mixture was spun at 200°C from 18 discharge holes using a composite fiber spinning device so that the core:sheath ratio was 6:4 (area ratio), to obtain a multifilament bright fiber (sheath-core type bright composite fiber) consisting of 18 single yarns and having an average outer diameter of 100 μm.

[0114] Comparative Example 1: Colored pellets were obtained by melt-mixing the flat bright pigment A, a polypropylene-ethylene random copolymer (melting point: 135°C), and a dispersant in the amounts shown in Table 2 in an extruder at 200°C. The colored pellets were fed into a general-purpose extruder, spun at 200°C, and stretched to obtain monofilament-shaped fibers having an average outer diameter of 100 µm.

[0115] Comparative Example 2 Phthalocyanine blue (manufactured by DIC Corporation, product name: Fastogen Blue AE-8 (average particle size: 80 nm)), polypropylene-ethylene random copolymer (melting point: 135°C), and a dispersant were melt-mixed at 200°C in an extruder in the amounts shown in Table 2 to obtain colored pellets. These colored pellets were fed into a general-purpose extruder, spun at 200°C, and stretched to obtain monofilament-form fibers having an average outer diameter of 100 µm.

[0116] Comparative Examples 3 to 5: Colored pellets were obtained in the same manner as in Example 1, except that the materials and blending amounts were changed as shown in Table 2. These colored pellets were fed to a general-purpose extruder, spun at 200°C, and stretched to obtain monofilament-form fibers having an average outer diameter of 100 μm.

[0117] Comparative Example 6: Flat bright pigment J, polypropylene-ethylene random copolymer (melting point: 135°C), and a dispersant were melt-mixed in an extruder at 200°C in the amounts shown in Table 2 to obtain colored pellets. These colored pellets were fed into a general-purpose extruder, spun at 200°C, and stretched to obtain monofilament-form fibers having an average outer diameter of 100 µm.

[0118] For the fibers (glitter fibers) produced in Examples 1 to 13 and Comparative Examples 1 to 6, 20 fibers each having a length of 10 cm were taped at one end to prepare evaluation samples.

[0119] [Gloss Evaluation] The evaluation samples of Examples 1 to 13 and Comparative Examples 1 to 6 were each visually inspected, and the gloss of the fibers was evaluated according to the following criteria. The evaluation results are shown in Tables 3 and 4. A: The fibers had sufficient gloss. B: The fibers had good gloss. C: The fibers had gloss at a level that was not problematic for practical use. D: The fibers had no gloss.

[0120] [Evaluation of brilliance] The evaluation samples of Examples 1 to 13 and Comparative Examples 1 to 6 were each visually inspected, and the brilliance (metallic luster) of the fibers was evaluated according to the following criteria. The evaluation results are shown in Tables 3 and 4. A: A strong brilliance (metallic luster) was visually observed on the fibers. B: A brilliance (metallic luster) was visually observed on the fibers. C: No brilliance (metallic luster) was visually observed on the fibers.

[0121] [Polarization Evaluation] The evaluation samples of Examples 1 to 13 and Comparative Examples 1 to 6 were each observed at different viewing angles, and changes in hue and luminance were evaluated according to the following criteria. The evaluation results are shown in Tables 3 and 4. A: Changing the viewing angle caused a significant change in hue and luminance. B: Changing the viewing angle caused a change in hue and luminance. C: Changing the viewing angle caused little change in hue and luminance, or no change.

[0122]

[0123]

[0124] Furthermore, the fibers of Examples 1, 5, 7, 8, and 13 and Comparative Example 6 were evaluated as follows. Measurement samples were prepared by wrapping the above-mentioned glittering fiber around a rectangular parallelepiped ABS resin substrate (approximately 60 mm long, 25 mm wide, and 1 mm thick) in one or four turns, ensuring no visible gaps around the central region (20 mm long, 25 mm wide, and 1 mm thick). A UV-Visible-Near-Infrared Spectrophotometer (manufactured by JASCO Corporation, product name: V-670) was used as the measurement device. After baseline measurement on the ABS resin substrate, the central region of each measurement sample was subjected to absorption spectrum measurement in the visible light wavelength range (400-800 nm). By subtracting the baseline, absorption spectrum A for the sample wound once and absorption spectrum B for the sample wound four times were obtained for each fiber. As an example, absorption spectra A and B for Example 1 are shown in FIG. 1 . For absorption spectrum A (one winding), the third absorption maximum wavelength was 633 nm, while for absorption spectrum B (four windings), the third absorption maximum wavelength was 679 nm, indicating a significant change in the absorption spectrum between one winding and four windings. As another example, Figure 2 shows absorption spectra A and B of Example 5. For absorption spectrum A (one winding), the second absorption maximum wavelength was 617 nm and the third absorption maximum wavelength was 419 nm, while for absorption spectrum B (four windings), the second absorption maximum wavelength was 678 nm and the third absorption maximum wavelength was 614 nm, indicating a significant change in the absorption spectrum between one winding and four windings. The first to third absorption maximum wavelengths of the absorption spectrum of each fiber are listed in Table 5.

[0125]

[0126] Application Example 1: Fabrication of a Toy Doll The glittering fiber of Example 1 was implanted onto the head of a doll using a conventional method (e.g., a hair implantation machine) to fabricate a toy doll with hair made of the glittering fiber. The hair of the toy doll had a good luster and excellent glitter and polarization properties. Furthermore, the apparent color changed depending on the viewing angle. In the toy doll, light easily penetrated areas where the hair was not densely packed (e.g., the tips of the hair), and the color of the transmitted light, i.e., the color of the coloring pigment, was relatively strong. On the other hand, in areas where the hair was densely packed (e.g., around the back of the head), light was less likely to penetrate, and the color of the reflected light, i.e., the color of the flat glittering pigment and the coloring pigment, or a mixture of these colors, was apparent. Therefore, the hair of the toy doll using the glittering fiber of this embodiment exhibited different colors depending on the location, demonstrating excellent marketability and a wide variety of colors.

[0127] Application Example 2: Fabrication of Hair Extensions The glittering fiber of Example 3 was attached to a clip using a conventional method to fabricate a hair extension. The hair extension had good luster and excellent glitter and polarization properties. Furthermore, the visually perceived color changed depending on the viewing angle; different colors were visually perceived when cooled to 14°C or below and when heated to 38°C or above. When this hair extension was attached to human hair, the hair extension exhibited a variety of colors depending on the lighting and / or the viewing angle, and therefore the hair extension could impart design features to hair and enhance its decorativeness.

[0128] Application Example 3: Fabrication of Clothing The glittering fiber of Example 5 was used as part of the warp and weft to obtain a fabric (plain woven fabric) with a grid pattern formed using the glittering fiber. This fabric was cut and sewn to produce clothing (shirts). The above clothing had good glitter and polarization of the grid pattern. Furthermore, the apparent color changed depending on the viewing angle. This shirt had a highly decorative and highly marketable grid pattern that exhibited a variety of colors depending on the lighting and / or viewing angle.

[0129] Application Example 4: Fabrication of Strap The glittering fiber of Example 7 was braided using an 8-ply round cord-making machine to obtain a braided cord. This braided cord was folded in half from the center, the ends were overlapped, a thin thread was passed through the center of each end and tied together, and a plastic protective member was attached to produce a strap. The strap had good gloss and was excellent in glitter and polarization properties. Furthermore, the visible color changed depending on the viewing angle. This strap exhibited a variety of colors depending on the lighting and / or the viewing angle, making it highly decorative and a highly marketable item.

[0130] Application Example 5: Fabrication of a Fan Using the glittering fiber of Example 9, a fabric (knitted fabric) was obtained on a knitting machine. This fabric was cut to obtain a fan surface. This fan surface was attached to the ribs and center ribs to produce a fan. The fan had good gloss and was excellent in glitter and polarization properties. Furthermore, the visible color changed depending on the viewing angle. This fan exhibited a variety of color changes depending on the lighting and / or the viewing angle, and therefore had a high level of design and was an excellent product.

[0131] Application Example 6: Preparation of Knitted Cord The glittering fiber of Example 12 was knitted using a four-needle knitting machine to prepare a lily yarn (knitted cord). The knitted cord had good luster, brilliance, and polarization. Furthermore, the color perceived changed depending on the viewing angle; different colors were perceived when cooled to 14°C or below and when heated to 38°C or above. When this knitted cord was sewn onto a doll's clothing as a string-like ornament, the ornament (knitted cord) exhibited a variety of colors depending on the lighting and / or the viewing angle, thereby adding design and enhancing the decorativeness of the doll's clothing.

[0132] This application claims priority from Japanese Patent Application No. 2023-102006, filed June 21, 2023. Japanese Patent Application No. 2023-102006 is incorporated herein by reference.

Claims

1. A brilliant fiber comprising a flat bright pigment, a coloring pigment, and a resin, wherein the flat bright pigment is iron oxide-coated flat aluminum particles having flat aluminum particles and an iron oxide layer covering the flat aluminum particles, or iron oxide-coated flat silicon dioxide particles having flat silicon dioxide particles and an iron oxide layer covering the silicon dioxide particles, and the amount of iron element in the flat bright pigment is 5 to 400 parts by mass per 100 parts by mass of aluminum element or silicon element in the flat bright pigment.

2. The photoluminescent fiber according to claim 1, wherein said color pigment comprises a blue pigment.

3. The glittering fiber according to claim 1 or 2, wherein the iron oxide-coated flat aluminum particles have a reflective layer containing silicon dioxide between the flat aluminum particles and the iron oxide layer.

4. The brilliant fiber according to claim 3, wherein the amount of silicon element in the flat brilliant pigment is 5 to 50 parts by mass per 100 parts by mass of aluminum element in the flat brilliant pigment.

5. The brilliant fiber according to any one of claims 1 to 4, wherein the average particle size of the flat brilliant pigment is 1 to 70 μm.

6. The photoluminescent fiber according to any one of claims 1 to 5, wherein the resin is selected from the group consisting of polyolefin, polyamide, polyester, acrylonitrile resin, polyvinyl chloride, polyvinylidene chloride, and vinyl chloride-vinylidene chloride copolymer resin.

7. The brilliant fiber according to any one of claims 1 to 6, wherein the flat brilliant pigment is blended in an amount within the range of 0.05 to 3 mass % relative to the total mass of the brilliant fiber.

8. The photoluminescent fiber according to any one of claims 1 to 7, which contains a color-changing material.

9. The glittering fiber according to any one of claims 1 to 8, having an average outer diameter of 10 to 300 µm.

10. A photoluminescent fiber as claimed in any one of claims 1 to 9, wherein an absorption spectrum A of the photoluminescent fiber measured after wrapping the photoluminescent fiber once around a substrate so as to cover at least a portion of the substrate measured as a baseline in the absorption spectrum measurement, and an absorption spectrum B of the photoluminescent fiber measured after wrapping the photoluminescent fiber four times around the substrate, differ by 10 nm or more in one or more selected from the group consisting of a first absorption maximum wavelength, a second absorption maximum wavelength and a third absorption maximum wavelength.

11. A toy or decorative item comprising the photoluminescent fiber according to any one of claims 1 to 10.