阅读说明：本技术 人造毛发用纤维 (Fiber for artificial hair ) 是由 村冈乔梓 武井淳 于 2020-06-01 设计创作，主要内容包括：本发明提供一种可抑制结的形成的人造毛发用纤维。根据本发明,提供一种人造毛发用纤维,其由树脂组合物拉伸而成的纤维构成,将未拉伸丝在100℃的初始拉伸应力设为F0,将拉伸2.5倍时的拉伸应力设为F1时,将所述树脂组合物纺丝得到的未拉伸丝的F1/F0为1.2以上。(The invention provides a fiber for artificial hair, which can inhibit the formation of knots. According to the present invention, there is provided a fiber for artificial hair comprising a fiber obtained by drawing a resin composition, wherein F1/F0 of an undrawn yarn obtained by spinning the resin composition is 1.2 or more, where F0 is an initial tensile stress at 100 ℃ and F1 is a tensile stress at 2.5 times.)

1. A fiber for artificial hair, which is composed of a fiber obtained by drawing a resin composition,

when the initial tensile stress of the undrawn yarn at 100 ℃ is F0 and the tensile stress at 2.5 times elongation is F1,

the undrawn yarn obtained by spinning the resin composition has an F1/F0 ratio of 1.2 or more.

2. The fiber for artificial hair according to claim 1, wherein,

the resin composition contains a base resin containing a No. 1 resin,

the undrawn yarn obtained by spinning the resin 1 has an F1/F0 ratio of 1.3 or more.

3. The fiber for artificial hair according to claim 2, wherein,

the content of the 1 st resin in the matrix resin is 50 mass% or more.

4. The fiber for artificial hair according to claim 2 or 3, wherein,

the No. 1 resin is polyamide.

Technical Field

The present invention relates to a fiber used for artificial hair such as a wig head, a wig, and a hair extension which can be worn or removed (hereinafter, referred to simply as "fiber for artificial hair").

Background

Patent document 1 discloses a fiber for artificial hair obtained by fiberizing a resin composition containing a polyamide and a brominated flame retardant.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-246844

Disclosure of Invention

Problems to be solved by the invention

Patent document 1 discloses that an undrawn yarn formed by melt spinning is drawn to produce a fiber for artificial hair, but the drawing of the yarn is not uniform during drawing, and the drawn yarn may form nodules. If knots are present in the fibers for artificial hair, the feeling of touch is deteriorated.

The present invention has been made in view of the above circumstances, and provides a fiber for artificial hair that can suppress the formation of knots.

Means for solving the problems

According to the present invention, there is provided an artificial hair fiber comprising a fiber obtained by drawing a resin composition, wherein F1/F0 of an undrawn yarn obtained by spinning the resin composition is 1.2 or more, where F0 is an initial tensile stress at 100 ℃ and F1 is a tensile stress at 2.5 times.

The present inventors have intensively studied and found that an artificial hair fiber in which the occurrence of knots can be suppressed can be obtained by producing an artificial hair fiber by drawing an undrawn yarn having an F1/F0 ratio of 1.2 or more, and completed the present invention.

Detailed Description

Embodiments of the present invention will be described below.

The artificial hair fiber of the present embodiment is made of a fiber obtained by stretching a resin composition, wherein the initial tensile stress of an undrawn yarn is F0, and the tensile stress at 2.5 times stretching is F1,

the undrawn yarn obtained by spinning the resin composition has an F1/F0 ratio (hereinafter referred to as "F1/F0 ratio of the resin composition") of 1.2 or more.

< resin composition >

The tensile stress of the undrawn yarn obtained by spinning the resin composition was measured at a temperature of 100 ℃ and a distance between chucks of 100mm at a drawing speed of 0.5 m/min. The initial tensile stress F0 is the tensile stress immediately after the start of measurement (specifically, when the undrawn yarn is elongated by 1%), and the tensile stress F1 at 2.5 times the elongation is the tensile stress at 2.5 times the elongation of the undrawn yarn.

F1/F0 is an index showing that the tensile stress increases with the stretching. A larger F1/F0 indicates a larger degree of increase in tensile stress with stretching (degree of strain hardening). When F1/F0 is small, the portion having a smaller stretching degree is more easily stretched. Since knots are easily formed in a portion having a small degree of stretch, the use of an undrawn yarn having a large F1/F0 ratio can suppress the formation of knots. Specifically, the generation of a knot can be suppressed when F1/F0 is 1.2 or more, and the generation of a knot can be further suppressed when F1/F0 is 1.3 or more. F1/F0 is more preferably 1.4 or more. The upper limit of F1/F0 is preferably 2.0 or less, more preferably 1.8 or less, and still more preferably 1.6 or less. In this case, the speed of melt spinning during production is easily increased, and productivity is excellent.

< matrix resin >

The resin composition constituting the fiber for artificial hair of the present embodiment contains a matrix resin and optionally contains an additive such as a flame retardant. The matrix resin is contained in the resin composition preferably at least 50 mass%, more preferably at least 80 mass%. In this case, the resin composition is easily melt-molded.

The undrawn yarn obtained by spinning a matrix resin preferably has an F1/F0 ratio (hereinafter referred to as "F1/F0 ratio of matrix resin") of 1.3 or more, more preferably 1.4 or more. In this case, F1/F0 of the resin composition tends to be large. F1/F0 of the matrix resin is preferably 2.0 or less.

The composition of the matrix resin of the resin composition of the present embodiment is not particularly limited, and is preferably composed of at least 1 kind of polyamide, polyester, vinyl chloride, and the like. The matrix resin preferably contains 50 mass% or more of polyamide, and more preferably 80 mass% or more. In this case, the fiber for artificial hair having excellent heat resistance and touch can be easily obtained.

The polyamide preferably contains an aliphatic polyamide, and may contain an aliphatic polyamide and a semi-aromatic polyamide having a skeleton obtained by polycondensation of an aliphatic diamine and an aromatic dicarboxylic acid. The polyamide preferably contains 50 mass% or more of an aliphatic polyamide, and more preferably the matrix resin contains 50 mass% or more of an aliphatic polyamide. In this case, the artificial hair fiber is particularly excellent in touch feeling.

The aliphatic polyamide is a polyamide having no aromatic ring, and examples of the aliphatic polyamide include n-nylon formed by ring-opening polymerization of lactam and n, m-nylon synthesized by copolycondensation of aliphatic diamine and aliphatic dicarboxylic acid. Examples of the aliphatic polyamide include polyamide 6 and polyamide 66. From the viewpoint of heat resistance, polyamide 66 is preferred.

Examples of the semi-aromatic polyamide include polyamide 6T, polyamide 9T, and polyamide 10T; and modified polyamide 6T, modified polyamide 9T, and modified polyamide 10T obtained by copolymerizing these modifying monomers as a matrix. Among them, polyamide 10T is preferable from the viewpoint of ease of melt molding.

The polyester is for example PET.

The matrix resin preferably contains the 1 st resin, and the undrawn yarn obtained by spinning the 1 st resin preferably has an F1/F0 ratio (hereinafter referred to as "F1/F0 ratio for the 1 st resin") of 1.3 or more. In this case, F1/F0 of the resin composition tends to be large. The content of the 1 st resin in the matrix resin is, for example, 30% by mass or more, preferably 50% by mass or more, more preferably 65% by mass or more, and further preferably 80% by mass or more. In this case, F1/F0 of the resin composition is further likely to be large.

The 1 st resin preferably has a melt viscosity of 100(Pa · s) or more at 300 ℃ and a shear rate of 2400 (1/s). In this case, the value of F1/F0 of the 1 st resin tends to be large. The melt viscosity of the 1 st resin under the above conditions is preferably 110(Pa · s) or more. In this case, the value of F1/F0 of the 1 st resin tends to be large.

The 1 st resin is preferably a polyamide, more preferably an aliphatic polyamide, still more preferably polyamide 6 or polyamide 66, and still more preferably polyamide 66. In this case, the value of F1/F0 of the 1 st resin is particularly liable to increase.

(flame retardant)

The artificial hair fiber of the present invention preferably contains a flame retardant. The flame retardant is preferably a brominated flame retardant. The amount of the flame retardant to be added is preferably 3 to 30 parts by mass, more preferably 5 to 25 parts by mass, and still more preferably 10 to 25 parts by mass, based on 100 parts by mass of the base resin. In this case, the fiber for artificial hair is particularly excellent in appearance, styling properties and flame retardancy.

Examples of the bromine-based flame retardant include brominated phenol condensates, brominated polystyrene resins, brominated benzyl acrylate-based flame retardants, brominated epoxy resins, brominated phenoxy resins, brominated polycarbonate resins, and bromine-containing triazine-based compounds.

(other additives)

The resin composition used in the present embodiment may contain, for example, additives such as a flame retardant aid, fine particles, a heat resistant agent, a light stabilizer, a fluorescent agent, an antioxidant, an antistatic agent, a pigment, a dye, a plasticizer, and a lubricant, as needed.

< production Process >

An example of a process for producing fibers for artificial hair will be described below.

The method for producing a fiber for artificial hair according to one embodiment of the present invention includes a melt spinning step, a drawing step, and an annealing step.

The respective steps will be described in detail below.

(melt spinning Process)

In the melt spinning step, the resin composition is melt spun to produce an undrawn yarn. Specifically, the resin composition is first melt-kneaded. As an apparatus for performing melt kneading, various commonly used kneading machines can be used. Examples of the melt-kneading include a uniaxial extruder, a biaxial extruder, a roll, a Banbury mixer, and a kneader. Among them, a twin-screw extruder is preferable from the viewpoint of adjustment of kneading degree and easiness of operation. The fiber for artificial hair can be produced by melt spinning according to the kind of polyamide by a usual melt spinning method under an appropriate temperature condition.

The fiber for artificial hair in the present embodiment preferably has a single fiber fineness of 20 to 100dtex, more preferably 35 to 80 dtex. In order to obtain such a single-filament fineness, the fineness of the fiber (undrawn yarn) immediately after the melt spinning step is preferably 300dtex or less. This is because if the fineness of the undrawn yarn is small, the draw ratio can be reduced to obtain a fine fineness of the fiber for artificial hair, and the fiber for artificial hair after the drawing treatment is less likely to produce luster, and thus the semi-gloss to the seventy-gloss state can be easily maintained.

(stretching Process)

In the drawing step, the obtained undrawn yarn is drawn at a draw ratio of 1.5 to 5.0 times to produce a drawn yarn. By drawing in this manner, drawn yarns having a fine fineness of 100dtex or less can be obtained, and the tensile strength of the fibers can be improved. The stretch ratio is preferably 2.0 to 4.0 times. When the draw ratio is appropriately large, the fiber strength tends to be appropriately exhibited, and when the draw ratio is appropriately small, the yarn breakage tends to be less likely to occur during the drawing treatment.

The temperature during the stretching treatment is preferably 90 to 120 ℃. If the stretching temperature is too low, the fiber strength tends to be low and yarn breakage tends to occur, and if it is too high, the touch of the obtained fiber tends to be smooth like plastic.

(annealing step)

In the annealing step, the drawn yarn is preferably heat-treated at a heat treatment temperature of 150 to 200 ℃. The heat treatment can reduce the heat shrinkage of the drawn yarn. The heat treatment may be performed continuously after the stretching treatment, or may be performed after the winding treatment with a time interval. The heat treatment temperature is preferably 160 ℃ or higher, more preferably 170 ℃ or higher, and still more preferably 180 ℃ or higher.

Examples

< production of fibers for Artificial Hair for examples and comparative examples >

The polyamide, PET and the brominated flame retardant dried to a moisture absorption of less than 1000ppm were mixed in the compounding ratio shown in Table 1. In table 1, the numerical values of the amounts of polyamide, PET and bromine-based flame retardant are parts by mass. Using the mixed materialsThe twin-screw extruder was melt-kneaded at a barrel set temperature of 280 ℃, then adjusted to a constant discharge rate by a gear pump, melt-spun in the direction of a plumb from a die having a temperature of 295 ℃ and a hole diameter of 0.5mm per root, and the undrawn yarn was wound at a constant speed around a haul-off machine disposed 2m directly below a nozzle. The ratio F1/F0 of the initial tensile stress F0 to the tensile stress F1 at 2.5 times elongation of the obtained undrawn yarn was measured according to the evaluation method and criteria described below. The results are shown in table 1.

The obtained undrawn yarn was drawn at 100 ℃ and then annealed at 180 ℃ to obtain a fiber for artificial hair having a predetermined fineness. The stretching ratio is 2.3 times and the relaxation rate during annealing is 6-7%. The relaxation rate during annealing is a value calculated from (the rotation speed of the take-up roll during annealing)/(the rotation speed of the transport roll during annealing).

The obtained artificial hair fiber was subjected to stretchability evaluation according to the following evaluation method and criteria. The results are shown in table 1.

Further, the melt viscosity was measured with 3 kinds of PA66 shown in table 1. The results are shown in Table 2.

[ Table 1]

[ Table 2]

The following materials were used as the materials in tables 1 to 2. The melt viscosity in the following is a value measured at 300 ℃ and a shear rate 2400 (1/s).

PA66(A) product of our company, F1/F0 ═ 1.55, melt viscosity 163(Pa · s)

PA66(B), product of our company, F1/F0 ═ 1.54, melt viscosity 145(Pa · s)

PA66(C), product of our company, F1/F0 ═ 1.07, melt viscosity 75(Pa · s)

PA6 product of this company, F1/F0 ═ 1.46, melt viscosity 130(Pa · s)

PA10T manufactured by Daicel-Evonik Ltd., VESTAMIDHOPlusm3000, F1/F0 ═ 1.16, melt viscosity 68 (Pa. s)

PET-Sanjing chemical Co., Ltd., J125S, F1/F0 ═ 1.14, melt viscosity 67 (Pa. s)

Brominated epoxy resin SRT-20000 made by saka pharmaceutical industries, Ltd

< various measurements and evaluations >

Various properties and physical properties were measured and evaluated by the methods shown below.

(tensile stress)

The tensile stress in examples and comparative examples was measured using STROGRAPHT (manufactured by TOYOBO CORPORATION Co., Ltd.) under conditions of a temperature of 100 ℃, a nip distance of 100mm, a drawing speed of 0.5 m/min and a fiber diameter of 125. mu.m. The initial tensile stress F0 is the tensile stress immediately after the start of measurement (specifically, when the undrawn yarn is elongated by 1%), and the tensile stress F1 when the undrawn yarn is stretched by 2.5 times is the tensile stress when the undrawn yarn is stretched by 2.5 times.

(melt viscosity)

The melt viscosities of examples and comparative examples were measured according to JIS K7199 using Capilograph1D (manufactured by Toyo Seiki Seisaku-Sho Co., Ltd.) at a temperature of 300 ℃ and a shear rate shown in Table 2.

(stretchability evaluation)

Fibers for artificial hair prepared at a draw ratio of 2.5 times or 4 times were visually evaluated, and the number of knots was counted per 1 piece or 10 m.

< examination >

The stretchability was good in all examples in which F1/F0 was 1.2 or more, and was not good in all comparative examples. Further, the drawability was particularly good in examples 1 to 4 in which F1/F0 was 1.3 or more.