JP5914469B2 - Artificial hair fibers and hair products - Google Patents

Description

  The present invention relates to a fiber for artificial hair and a hair product using the same.

  Conventionally, artificial hair made of synthetic fibers has been used for hair products such as wigs and hair wigs. Although artificial hair is often straight hair as it is, in recent years, fibers for artificial hair that can be processed, such as curling, have been demanded from the expansion of fashion usage of artificial hair.

  As a fiber for artificial hair excellent in curl setting property, for example, there is a flame-retardant polyester-based artificial hair (see Patent Document 1). Since this artificial hair fiber has high heat resistance, it can be heated at high temperature with a hair iron or the like and has excellent curling properties.

  However, in order to avoid thermal damage, hair product manufacturers often perform curling at a low temperature of 90 to 150 ° C. compared to hair irons and the like, and the above flame retardant artificial hair fibers are sufficiently curled. There was a problem that I could not.

JP 2009-235626 A

  Therefore, the main object of the present invention is to provide a fiber for artificial hair having high processability such as curling.

The present invention is to provide a product using the fiber for artificial hair and the artificial hair fibers, storage modulus at ₉₀ and 0.99 ° C. 'storage modulus E at 90 ° C. in a' storage modulus E with respect to temperature ₉₀ / E _'0.99' ratio E of _0.99 'E is a fiber for 3 to 20 artificial hair.
The curve of the storage elastic modulus E ′ with respect to the temperature has a glass state region where the storage elastic modulus E ′ is constant and a transition region where the rate of change is maximum at a higher temperature than the glass state region. It is more suitable for the present invention that the temperature coordinate of the intersection point where the tangent line passing through the glass state region and the tangent line passing through the transition region intersect the curve of the storage elastic modulus E ′ is 180 to 240 ° C.
The artificial hair fiber is more preferably produced from a resin composition containing as a main component either one or both of a polyester resin and a polyamide resin.
The resin composition is a fiber for artificial hair produced by melt-discharging the resin composition from a nozzle hole to produce an unstretched yarn, and then stretching the unstretched yarn. It is more preferable that the ratio D ₁ / D _{2 of} the magnification D ₁ stretched during production and the magnification D ₂ stretched during the stretching process is 1.5 to 14.0.
A hair product can also be produced using the artificial hair fibers.

  ADVANTAGE OF THE INVENTION According to this invention, the fiber for artificial hair with high workability can be provided.

It is a graph which shows the relationship between storage elastic modulus and temperature. It is a graph which shows the viscoelasticity of the fiber for artificial hair of an Example. It is a graph which shows the viscoelasticity of the fiber for artificial hair of a comparative example.

  Hereinafter, although the present invention is explained in detail, the present invention is not limited to each embodiment shown below.

  This invention provides the fiber for artificial hair excellent in curl property (styling property, set property). Artificial hair fibers are not particularly limited, and are, for example, synthetic fibers obtained by spinning a resin composition, or synthetic fibers obtained by attaching a treatment agent or the like.

  The forming process may be performed by any of the manufacturer of the fiber for artificial hair, the processor for the hair product, or the end consumer who has purchased the hair product. For example, a manufacturer of artificial hair fibers or hair products performs a molding process such as curling on the artificial hair fibers before market. The forming process may be performed at any stage before the artificial hair fiber is processed into a hair product, during the processing of the hair product, or after the processing into the hair product. The forming process is not limited to curling (wave), and includes cases where the wave is straight (straight hair).

  The forming method is not particularly limited, and a method of bringing a heating device such as a hair iron into contact (pressing) with the artificial hair fiber, or exposing the artificial hair fiber to hot air in a state of being wound around a core (such as a metal tube). There are a method, a method of heating the winding core itself, and the like. Generally, a method in which a winding core wound with artificial hair fibers is placed in a heating furnace (oven) and heated is used.

  The heating temperature (molding temperature) for molding is not particularly limited, and can be appropriately changed depending on the raw material of the fiber for artificial hair, but is generally in the range of 90 to 150 ° C. (molding temperature region).

  FIG. 1 is a schematic diagram for explaining the viscoelastic properties of artificial hair fibers. Synthetic fibers are reduced in both storage elastic modulus E ′ and loss elastic modulus E ″ by heating, and the larger the change rate, the easier the deformation of curls and the like. In the oven curl temperature region of FIG. 1, those having a large change rate are suitable for artificial hair fibers.

  1 is a change curve of the elastic modulus (E ′, E ″) of a commercially available heat-resistant artificial hair. Since the heat-resistant artificial hair has heat resistance, the elastic modulus at the molding temperature (E ′, E ″). ) Is small, and curl and other moldability are poor. If the elastic modulus (E ′, E ″) changes greatly at the molding temperature as indicated by reference symbols a and b in FIG. 1, it easily deforms at the molding temperature and the moldability is good.

  Changes in the elastic modulus (E ′, E ″) at the molding temperature can be adjusted by changing the composition of the resin composition used as the raw material for artificial hair fibers. For example, a thermoplastic resin having a low glass transition temperature can be used. If the main raw material is used, the elastic modulus (E ′, E ″) can be greatly changed at the molding temperature, but the heat resistance is poor.

  After the shaping process (after market), the end consumer may process the hair product according to personal preference (post-molding). Commercially available heating appliances (hair irons, etc.) are often used for post-molding, and the heating temperature varies from 60 to 240 ° C. There exists a tendency of high temperature (180-240 degreeC, post-molding temperature area | region) rather than the shaping | molding process.

  As shown by curve b, even if the rate of change in the molding temperature region is large, the one in which the fiber begins to melt before reaching the post-molding temperature region (iron curl temperature region in FIG. 1) May not be able to withstand, and may cause large shrinkage of the fiber, pain or breakage of the fiber.

  Therefore, as shown by the curve a, the one that does not melt before reaching the post-molding temperature region and that has a large change rate in the molding temperature region and the post-molding temperature region is most preferable. The change in the elastic modulus (E ′, E ″) is large even when melted, a and c in FIG. 1 are melted in the post-molding temperature region, and b is melted before reaching the post-molding temperature region. Since the artificial hair fibers are not heated at a high temperature exceeding the post-heating temperature region, if the rate of change is large in the post-molding temperature region, melting occurs in that region as in a and c. It doesn't matter.

  The molding temperature often used in the field of artificial hair is in the range of 90 to 150 ° C., and the post molding temperature preferred by consumers is in the range of 180 to 240 ° C., that is, the elastic modulus changes greatly in these regions. .

The larger the change in the elastic modulus, the better the curling property, but the too large change means shrinkage of the fiber. For example, temperature (° C.) ₉₀ / E _'150' ratio E of _{150 '90} and 150 ° C. storage modulus E at' the storage modulus E at 90 ° C. in 'the storage modulus E for is 3 to 20 More preferably, it is 4-10.
When E ′ ₉₀ / E ′ ₁₅₀ is less than 3, since the change in elastic modulus in the molding temperature region ( _{90 to 150} ° C.) is small, it is difficult to mold the curl and the curling property becomes poor. On the other hand, if E ′ ₉₀ / E ′ ₁₅₀ exceeds 20, the fiber contracts, resulting in poor curling properties. In addition, when E ′ ₉₀ / E ′ ₁₅₀ is 4 to 10, it is particularly preferable because excellent curling properties can be realized without contracting the fiber.

  In consideration of post-molding, those having high heat resistance are preferable, but if the heat resistance is too high, post-molding (iron curl) cannot be performed, so that the deformation temperature at which the glass state of the crystal collapses is in the range of 180 to 240 ° C. It is desirable to be. The deformation temperature is, for example, a tangent line passing through a region (glass state region) where the storage elastic modulus is constant in the storage elastic modulus curve, and a transition region where the change rate of the storage elastic modulus is the highest on the higher temperature side. It is the temperature at which the intersection with the tangent line passing through (or the transition point where the rate of change of the storage elastic modulus is the largest) is located.

  The fiber for artificial hair which satisfy | fills the above temperature and viscoelasticity can be manufactured by adjusting suitably the manufacturing conditions of fiber, and the mixing | blending of a raw material, for example.

<Resin composition>
The resin composition contains a thermoplastic resin as a main component (content of 50% by mass or more) and contains additives such as a flame retardant, a filler, a colorant, and an anti-aging agent as necessary. Viscoelasticity (E ′, E ″, etc.) can be adjusted by, for example, the blending ratio of two or more thermoplastic resins or the blending ratio of the thermoplastic resin and additives (flame retardant, filler, etc.). By blending two or more thermoplastic resins having different glass transition temperatures, fibers for artificial hair having a large elastic change in both the molding temperature region and the post-molding temperature region can be obtained.

  In addition to the above method, the viscoelasticity can be adjusted by adjusting the fiber production conditions. For example, viscoelasticity can be adjusted by appropriately changing the draft ratio and the draw ratio. The draft magnification is a magnification at which the resin exiting the nozzle hole is stretched until it is cooled, and the draw ratio is a magnification at which the undrawn yarn is stretched (a magnification at the time of stretching).

  The draft ratio and the draw ratio will be described in detail below. In the production process of artificial hair fibers, a composition containing a thermoplastic resin is heated and melted and discharged from a nozzle hole, and after passing through a heating cylinder as necessary, is cooled to obtain an undrawn yarn. A draft magnification is the magnification at which the yarn is cooled and undrawn after being discharged from the nozzle hole. The draw ratio can be calculated from the ratio of the undrawn yarn take-up speed to the discharge speed from the nozzle.

  The undrawn yarn is subjected to a drawing treatment in order to improve the tensile strength of the fiber. The drawing process is a process of drawing the undrawn yarn once cooled while heating it at a temperature lower than the heating and melting temperature at the time of spinning, until the undrawn yarn (before heat drawing) is drawn. The draw ratio is the draw ratio. The stretch ratio in this case can be calculated by the ratio of the undrawn yarn unwinding speed and the yarn winding speed after the stretching treatment.

<Thermoplastic resin>
The thermoplastic resin is not particularly limited, and vinyl chloride resin, acrylic resin, polypropylene resin, polylactic acid resin, polyester resin, polyamide resin, or the like can be used. However, if only resin with low heat resistance such as vinyl chloride resin is used, the fiber will be thermally damaged in post molding at high temperature (180 ° C or higher), so heat resistant resin such as polyamide resin and polyester resin may be used alone or in combination. It is desirable to do.

  Among these resins, the present invention is particularly excellent in terms of processability, strength, and the like, in particular, polyamide-based fibers mainly composed of polyamide resin and polyester-based fibers mainly composed of polyester resin.

  The polyamide fiber and the polyester fiber are preferably formed from a composition obtained by melt-kneading 100 parts by weight of a polyamide resin (or 100 parts by weight of a polyester resin) and 5 to 30 parts by weight of a phosphorus or bromine flame retardant. Fiber. In such a case, flame retardancy is greatly improved by a combination of a resin and a predetermined proportion of a phosphorus-based or bromine-based flame retardant.

  The type of polyamide resin used for the polyamide-based fiber is not particularly limited. For example, the polyamide resin is selected from the group consisting of nylon 6, nylon 6,6, nylon 4,6, nylon 12, nylon 6,10, and nylon 6,12. At least one resin is preferable, and nylon 6 and 6 are particularly preferable. When nylon 6 or 6 is used, the tactile feeling is particularly good. The weight average molecular weight (Mw) of the polyamide is, for example, any value within a range of 10,000 to 200,000, specifically 10,000, 20,000, 40,000, 60,000, 80,000, 100,000, There are 150,000 and 200,000.

  The type of polyester resin used for the polyester fiber is not particularly limited, but there are polyethylene terephthalate, polyphenylene ether, polypropylene terephthalate, polybutylene terephthalate, etc. Among them, polyethylene terephthalate is most suitable in terms of heat resistance and the like. .

  There is no limitation in particular in the kind of the said phosphorus flame retardant, If it is a phosphorus flame retardant generally used, it can be used. Specific examples include phosphate compounds, phosphonate compounds, phosphinate compounds, phosphine oxide compounds, phosphonite compounds, phosphinite compounds, phosphine compounds, and the like. These may be used alone or in combination of two or more.

  The brominated flame retardant is not particularly limited, and any brominated flame retardant that is generally used can be used. Specific examples include pentabromotoluene, hexabromobenzene, decabromodiphenyl, decabromodiphenyl ether, bis (tribromophenoxy) ethane, tetrabromophthalic anhydride, ethylenebis (tetrabromophthalimide), ethylenebis (pentabromophenyl), Bromine-containing phosphate ester flame retardants such as octabromotrimethylphenylindane and tris (tribromoneopentyl) phosphate, brominated polystyrene flame retardant, brominated polybenzyl acrylate flame retardant, brominated epoxy flame retardant, brominated Phenoxy flame retardant, brominated polycarbonate flame retardant, tetrabromobisphenol A, tetrabromobisphenol A-bis (2,3-dibromopropyl ether), tetrabromobisphenol A-bis (a) Ruether), tetrabromobisphenol A-bis (hydroxyethyl ether), tetrabromobisphenol A derivatives, bromine-containing triazine compounds such as tris (tribromophenoxy) triazine, bromine such as tris (2,3-dibromopropyl) isocyanurate Examples thereof include isocyanuric acid-based compounds. These may be used alone or in combination of two or more.

  The content of the phosphorus-based or brominated flame retardant is an amount such that the ratio with respect to 100 parts by weight of polyamide (or 100 parts by weight of the polyester resin) is 5 to 30 parts by weight, and 5 to 20 parts by weight. Is more preferable. This is because, within such a range, deterioration of various physical properties can be avoided while ensuring sufficient flame retardancy.

  Furthermore, you may contain the microparticles | fine-particles of the quantity used as the ratio with respect to 100 weight part of polyamide resins (or 100 weight part of polyester resins) 0.1-5 weight part. When fine particles are included at such a ratio, the surface and the gloss of the fiber surface can be adjusted by forming irregularities on the fiber surface, and the surface area of the fiber surface is increased, resulting in the hygroscopicity of the fiber. This is because a specific effect that can be improved is obtained. The ratio of the fine particles to 100 parts by weight of the polyamide resin (or 100 parts by weight of the polyester resin) is more preferably 0.2 to 3 parts by weight, and further preferably 0.2 to 2 parts by weight. This is because the above effect is particularly remarkable in such a ratio.

  The average particle size of the fine particles is preferably 0.1 to 15 μm, more preferably 0.2 to 10 μm, and further preferably 0.5 to 8 μm. This is because, within such a range, the effect of adjusting gloss and gloss is sufficiently large, and the fiber strength is not easily lowered by the addition of fine particles.

  The fine particles may be organic fine particles or inorganic fine particles, and may include both organic fine particles and inorganic fine particles. The organic fine particles only need to be at least partially incompatible with the polyamide resin or the polyester resin, and examples thereof include fine particles made of a crosslinked acrylic resin or a crosslinked polyester resin.

  The cross-linked acrylic particles can be obtained by water-dispersing an acrylic monomer and a cross-linking agent and performing cross-linking curing. Examples of acrylic monomers used here include acrylic acid and derivatives of acrylic acid, such as methyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, hydroxyethyl acrylate, acrylonitrile, acrylamide, N -Methylolacrylamide; or methacrylic acid, methacrylic acid derivatives such as methyl methacrylate, butyl methacrylate, hexyl methacrylate, glycidyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, N-vinyl-2-pyrrolidone methacrylate, methacrylate Examples thereof include vinyl monomers having one vinyl group in one molecule, such as rhonitrile, methacrylamide, N-methylol methacrylamide, 2-hydroxyethyl methacrylate, and the like. These may be used alone or in combination of two or more.

  The crosslinked polyester particles can be obtained by water-dispersing an unsaturated polyester and a vinyl monomer, followed by crosslinking and curing. The unsaturated polyester used here is not particularly limited, and examples thereof include those obtained by polymerizing an α, β-unsaturated acid or a mixture of the unsaturated acid and a dihydric alcohol or a trihydric alcohol. Can do. Examples of the unsaturated acid include fumaric acid, maleic acid, itaconic acid, and examples of the saturated acid include phthalic acid, terephthalic acid, succinic acid, glutaric acid, tetrahydrophthalic acid, adipic acid, and sebacic acid. It is done. Examples of the dihydric alcohol and trihydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, 1,3-propanediol, 1,6-hexanediol, and trimethylolpropane. On the other hand, the vinyl monomer is not particularly limited, and examples thereof include styrene, chlorostyrene, vinyl toluene, divinylbenzene, acrylic acid, methyl acrylate, acrylonitrile, ethyl acrylate, and diallyl phthalate.

  The cross-linking agent may be any monomer having two or more vinyl groups in one molecule, but preferably has two vinyl groups in one molecule. Preferred monomers for the crosslinking agent include, for example, divinylbenzene, reaction products of glycol and methacrylic acid or acrylic acid, such as ethylene glycol dimethacrylate and neopentyl glycol dimethacrylate, but are not limited thereto. is not. The addition amount of the crosslinking agent is preferably 0.02 to 5 parts by weight with respect to 100 parts by weight of the acrylic monomer. The polymerization initiator is preferably a peroxide radical polymerization initiator, and examples thereof include benzoyl peroxide, 2-ethylhexyl perbenzoate, di-tert-butyl peroxide, cumene hydroperoxide, and methyl ethyl ketone peroxide. The radical polymerization initiator is preferably used in an amount of 0.05 to 10 parts by weight with respect to 100 parts by weight of the acrylic monomer.

  The inorganic fine particles preferably have a refractive index close to the refractive index of the polyamide and / or phosphorus-containing flame retardant because of the influence on the transparency and color developability of the fiber. For example, calcium carbonate, silicon oxide, oxidation Examples include titanium, aluminum oxide, zinc oxide, talc, kaolin, montmorillonite, bentonite, and mica.

  In addition to the fine particles and flame retardants described above, flame retardant aids, heat-resistant agents, light stabilizers, fluorescent agents, antioxidants, antistatic agents, plasticizers, lubricants, resins other than thermoplastic resins, etc. Can be made. By containing a colorant such as a pigment, a pre-colored fiber (so-called original fiber) can be obtained.

<Manufacturing process>
Although an example of the synthetic fiber manufacturing process will be described below, the present invention is not limited to this.
A thermoplastic resin such as a polyamide resin or a polyester resin is dry-blended in advance with a desired ratio of the above-described additives such as a flame retardant or particles, and then melt-kneaded using a kneader. As an apparatus for melt kneading, various general kneaders can be used. Examples of the melt kneading include a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, and a kneader. Among these, a twin screw extruder is preferable from the viewpoint of adjusting the degree of kneading and ease of operation. The kneaded product obtained by melt kneading can be produced by melt spinning by a melt spinning method.

  In melt spinning, for example, melt spinning is performed at a temperature of 270 to 310 ° C. in a melt spinning apparatus such as an extruder, a gear pump, a die, etc. The spun yarn is obtained by taking up at a speed of 50 to 5000 m / min. Further, the spun yarn may be cooled in a water tank containing cooling water to control the fineness. The temperature and length of the heating cylinder, the temperature and spray amount of the cold air tower, the temperature of the cooling water tank, the cooling time, and the take-up speed can be appropriately adjusted according to the discharge amount and the number of holes in the base.

  At the time of melt spinning, a spinning nozzle having a special nozzle hole shape can be used, and the cross-sectional shape of the fiber for artificial hair can be changed to a deformed shape such as a saddle shape, a Y shape, an H shape, and an X shape.

  The obtained undrawn yarn is subjected to a heat drawing treatment in order to improve the tensile strength of the fiber. The thermal drawing process is a two-step method in which an undrawn yarn is wound around a bobbin and then drawn in a step separate from the melt spinning step, or direct spinning in which the yarn is continuously drawn from the melt spinning step without being wound around the bobbin. Any method of stretching may be used. Further, the thermal stretching treatment is performed by a one-stage stretching method in which stretching is performed at a time to a target stretching ratio or a multi-stage stretching method in which stretching is performed to a target stretching ratio by two or more stretching. As a heating means in the heat stretching treatment, a heating roller, a heat plate, a steam jet device, a hot water tank, or the like can be used, and these can be used in combination as appropriate.

  The fineness of the synthetic fiber is 30 to 80 dtex, preferably 35 to 75 dtex, which is suitable for artificial hair. Among the synthetic fibers, the polyamide-based fiber is a non-crimp raw fiber-like fiber, and the fineness thereof is usually 10 to 100 dtex, more preferably 30 to 80 dtex, and further preferably 35 to 75 dtex.

<Post-processing>
The manufactured synthetic fiber may be used as it is as a fiber for artificial hair as it is, but it is also possible to improve the tactile sensation and the like by applying a treatment agent containing an oil such as silicone. The treatment agent may be applied before, during, or after processing the synthetic fiber into a hair product. More suitable in terms of etc.

  The artificial hair fiber may be used alone for a hair product (head ornament product), or may be used by mixing human hair or other artificial hair. The hair products are wigs, hair pieces, blades, extension hairs, doll hairs, etc., and the use of the fiber for artificial hair is not particularly limited. In addition to hair products, it can also be used for false eyelashes, false eyelashes, false eyebrows and the like.

  EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to only these examples.

<Manufacturing process>
Hereinafter, the manufacturing method of the fiber bundle for hair concerning an Example is demonstrated. The polyamide fiber (or polyester fiber) was produced by the following method. First, the polyamide resin (or polyester resin), phosphorus-based or brominated flame retardant, and fine particles as raw materials were each dried so that the water content contained was 100 ppm or less.

The following were used as raw materials.
Nylon 6: Ube Industries, Ltd. 1013B
Nylon 6, 6: Toray Industries, Inc., CM3001-N
Phosphorus flame retardant: Daihachi Chemical Industry Co., Ltd., PX-200
Brominated flame retardant: Albemarle Japan Co., Ltd., HP-7010
Fine particles: Cross-linked acrylic particles, average particle size 1.8 μm, Soken Chemical Co., Ltd. Polyester (PET): Mitsubishi Chemical Corporation, BK-2180

The blending (mass ratio) of the raw materials is shown in Table 1 below.

  Next, a predetermined amount of coloring pellets was added to the dried raw material, and dry blended with each of the mixed species and mixing ratios shown in Table 1. The dry blend was melt kneaded at a temperature of 280 ° C. And the kneaded material was shape | molded as a pellet molded object. Melt kneading and pellet molding were performed with a twin screw extruder.

  The pellet molded body was dried so that the water content contained was 100 ppm or less, and then molded into an undrawn yarn by a melt spinning machine. More specifically, as the nozzle of the spinneret in the melt spinning machine, a hole having a circular cross section and a nozzle hole diameter of 0.5 mm was used. With this melt spinning machine, the molten polymer of the pellet molded body was discharged from the nozzle hole in a state where the temperature was 280 ° C. The discharged molten polymer was cooled in a 50 ° C. water bath layer located 30 mm below the die and wound up. In this way, an undrawn yarn was obtained. The draft ratio was adjusted by changing the winding speed of the undrawn yarn.

  Next, the obtained undrawn yarn was drawn 4 times and then heat-treated. And the fiber comprised mainly by polyamide (or polyester) was obtained by winding at the speed | rate of 30 m / min. In drawing and heat treatment of the undrawn yarn, heat rolls heated to 85 ° C. and 200 ° C. were used. Thereby, the fiber concerning Examples 1-4 and Comparative Examples 1-2 was obtained. The draw ratio was adjusted by changing the unwinding speed of the undrawn yarn.

  The following evaluation test was done about the fiber of Examples 1-4 and Comparative Examples 1-2.

<Oven curl properties>
For the oven curl property, 2 g of a fiber bundle obtained by bundling fibers having a length of 50 cm was wound around an aluminum cylinder of 20 mmφ, and both ends were fixed. Next, the aluminum tube (with the fiber wound) was left in a temperature-controlled room at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours. Thereafter, the fiber bundle was removed from the stainless steel tube, and one end was fixed and suspended. The length from the root to the tip was evaluated by the value divided by the total length (50 cm) before curling. The smaller the value, the more curled. The evaluation is based on the following criteria, and excellent and good are acceptable values.
Excellent value is less than 0.75 Good value is 0.75 or more and less than 0.85 Defective value is 0.85 or more

<Processability>
The processability was evaluated according to the following criteria by examining the frequency of yarn breakage in the fiber manufacturing process (spinning, drawing). Excellent and good are acceptable values.
Excellent No thread breakage Good Good There is a thread breakage once every 30 minutes, but there is no problem with the quality of the product.

<Physical properties>
Ten fibers were randomly selected according to JIS-L1069 and a tensile test was performed to obtain an average value. The test temperature was 23 ° C., the relative humidity was 50%, the tensile speed was 200 mm / min, and the spatial distance (distance between chucks) was 200 mm. Excellent tensile strength (cN / dtex) of 1.0 to 2.0, excellent tensile strength (cN / dtex) of 0.5 to 3.0, tensile strength (cN / dtex) Those less than 0.5 or more than 3.0 were regarded as defective.

<Dynamic viscoelasticity>
Dynamic viscoelasticity (extension elastic modulus) was measured under the measurement conditions of a frequency of 1.0 Hz, a start temperature of 30 ° C., an end temperature of 260 ° C., and a temperature increase rate of 2 ° C./min. The measuring instrument used was DMS6100 manufactured by SII Nano Technology. The fiber was measured by setting a distance between chucks of 3 mm and sandwiching a bundle of 40 fibers.

The measurement results of the above tests are shown in Table 2 below along with the production conditions such as the type of resin, draft magnification, and draw ratio.

The ratio (draft ratio / draw ratio) relative stretch ratio _{D 2} of the draft ratio _{D 1,} to 1.5 to 14.0, the ratio of the storage modulus _{(E '90 / E' 150} ) were 3 to 20 Examples 1-4 were excellent not only in oven curl property and workability but also in strength. Among these, Examples 1 and 4 having a storage elastic modulus ratio (E ′ ₉₀ / E ′ ₁₅₀ ) of 4 to 10 showed particularly good results in oven curl properties.
When the ratio (D ₁ / D ₂ ) of the draft ratio D _{1 to} the draw ratio D ₂ is less than 1.5, the undrawn yarn is stretched too much at the time of drawing, and the yarn tends to break, so that the workability tends to deteriorate. become. On the other hand, if the ratio (D ₁ / D ₂ ) of the draft ratio D _{1 to} the draw ratio D ₂ exceeds 14.0, the drawing process (drawing of the undrawn yarn) is not sufficiently performed, so the tensile strength is small. Tend to be.
In Example 5, the ratio of storage elastic modulus (E ′ ₉₀ / E ′ ₁₅₀ ) was 3.6, and the oven curl property and workability were not good but good, but this range can also be used sufficiently. Has a range of characteristics. In Example 5, there against stretching ratio _{D 2} of the draft ratio _{D 1} even ratio _(D 1 / _{D 2)} is 1.5, the ratio of drawing ratio _{D 2} of the draft ratio _{D 1 (D 1} / _{D 2} ) Is in the range of good workability even at 1.5, and has a usable range of characteristics.
In Example 6, the ratio of storage elastic modulus (E ′ ₉₀ / E ′ ₁₅₀ ) was 18.5, and the oven curl property and physical properties (tensile strength) were not good but good. It has a range of characteristics that can be used. In Example 6, there ratio stretching ratio _{D 2} of the draft ratio _{D 1 (D 1 / D 2} ) is also 12, the ratio of drawing ratio _{D 2} of the draft ratio _{D 1 (D 1 / D 2} ) is No. 12 also has a tensile strength (physical property) in a good range and has a usable characteristic.

On the other hand, Comparative Example 1 having a storage elastic modulus ratio (E ′ ₉₀ / E ′ ₁₅₀ ) of less than 3 is inferior in oven curl property, and the storage elastic modulus ratio (E ′ ₉₀ / E ′ ₁₅₀ ) is 20. In Comparative Example 2, the strength was not only poor in oven curl but also in strength.

  The measurement result of the dynamic viscoelasticity of Example 1 is shown in FIG. 2, and the measurement result of the dynamic viscoelasticity of Comparative Example 1 is shown in FIG. As can be seen from FIG. 3, it was confirmed that the artificial hair fiber of Comparative Example 1 did not melt even at a high temperature of 240 ° C., retained the storage elastic modulus E ′, and had very high heat resistance. Is too high, the melt does not melt not only in the molding temperature region (90 to 150 ° C.) but also in the post-molding temperature region (180 to 240 ° C.), and the change in storage elastic modulus E ′ and loss elastic modulus E ″ is small. On the other hand, it was confirmed that the artificial hair fiber of Example 1 has a large rate of change in both the molding temperature region and the post-molding temperature region, and the moldability is very high.

Code M ₁ in FIG. 2 and 3, 'of the curve of the storage modulus E' The storage modulus E with respect to the temperature at a constant, indicates the tangent crystalline state through the region (glass state region) of the glassy state, the code M ₂ in FIG. at a high temperature side of the glass state region, the rate of change indicates a tangent line passing through the transition region becomes maximum. At the intersection P where the tangent line M ₁ passing through the glass state region and the tangent line M ₂ passing through the transition region intersect the storage elastic modulus E ′ curve, the crystal state collapses and melting starts. When the said FIG. 2 is seen, the fiber for artificial hair of Example 1 has the temperature coordinate of the intersection P in the range of 180-240 degreeC, and can process it with a commercially available hair iron (heating temperature 240 degrees C or less). I understand. On the other hand, in Comparative Example 1, it was confirmed that the temperature coordinate of the intersection point P exceeded 240 ° C., and it was difficult for the commercial hair iron to be heated and deformed.

The use of the fiber for artificial hair according to the present invention is not particularly limited, and can be used for various hair products such as wigs, hair pieces, blades, hair extensions such as extension hairs, or doll hairs. .

Claims (5)

₉₀ / E _'150 artificial hair fibers is 3-20' ratio E of _{150 '90} and the storage modulus E at 150 ° C.' storage modulus E at 90 ° C. in a 'storage modulus E with respect to temperature. The curve of the storage elastic modulus E ′ with respect to the temperature has a glass state region where the storage elastic modulus E ′ is constant, and a transition region where the rate of change is maximum at a higher temperature than the glass state region,
The fiber for artificial hair according to claim 1, wherein a temperature coordinate of an intersection point of a tangent line passing through the glass state region and a tangent line passing through the transition region with respect to the curve of the storage elastic modulus E 'is located at 180 to 240 ° C. .   The fiber for artificial hair according to claim 1 or 2, wherein the fiber is produced from a resin composition comprising as a main component a thermoplastic resin of one or both of a polyester resin and a polyamide resin. A fiber for artificial hair produced by melting and discharging the resin composition from a nozzle hole to produce an unstretched yarn, and then stretching the unstretched yarn,
The ratio D ₁ / D _{2 of} the magnification D ₁ stretched during production of undrawn yarn from melt discharge and the magnification D ₂ stretched during the stretching treatment is 1.5 to 14.0. Item 5. An artificial hair fiber according to Item 3. A hair product using the artificial hair fiber according to any one of claims 1 to 4.

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