JPWO2006135060A1 - Artificial hair fiber, method for producing the same, and hair ornament product - Google Patents

Abstract

Provided is a fiber for artificial hair having a good balance between softness and bulkiness. The cross section of the fiber is a shape partially overlapped with a plurality of circular cross-sectional areas arranged so as to have a bent portion. .2R0 (4) (where R0 is the radius of the circular cross-sectional area, and A0 is the width of the connecting portion). The fiber cross section is at least one selected from the group consisting of a U-shape, a C-shape, a Y-shape, and an H-shape, and the bending stiffness by the KES method is 1.2 to 3.5. × 10-2 N · cm 2 Artificial hair fiber.

Description

The present invention relates to a fiber for artificial hair used in the manufacture of hair ornament products such as wigs, hair pieces, blades, extension hairs, etc., a method for producing the same, and a hair ornament product formed therefrom.
Units such as “parts” and “%” indicating the composition of the resin composition are expressed on a mass basis unless otherwise specified.

  Since vinyl chloride resin fibers obtained by spinning vinyl chloride resins are excellent in transparency and flexibility, they are often used as artificial hair fibers used for hair decoration products such as wigs. For industrial production of vinyl chloride resin fibers, wet spinning, dry spinning, and melt spinning that melts and spins without using organic solvents are known. It has been.

  The melt spinning method is a method of extruding a resin at a high temperature and high pressure using an extruder. Since a vinyl chloride resin has a high melt viscosity and extremely low spinnability, the vinyl chloride resin is melt spun. There has been a problem that it is difficult to obtain a certain quality vinyl chloride resin fiber. As an industrial production method, a strand is extruded from a nozzle hole having a small cross-sectional area, introduced into a heated cylinder, where it is melted by heating and drawn to obtain an undrawn yarn. However, since one cross-sectional area is caused to flow out from a small nozzle hole, the pressure applied to the nozzle becomes high, and the design pressure of the extruder is exceeded, and the grease (scale around the nozzle) ) Is likely to occur. In order to solve these problems, means for blending a plasticizer and a vinyl chloride homopolymer having a low degree of polymerization has been proposed (see Patent Document 1).

  Conventional synthetic fibers used as artificial hair fibers for hair include polyester fibers, acrylic fibers, and polyvinyl chloride fibers. In particular, polyvinyl chloride fibers are often used as artificial hair fibers for hair because they are excellent in strength, elongation, transparency and curl retention. In addition, when processing these products into products such as wigs and hairpieces, in the case of pursuing bulkiness, select a synthetic fiber with a low specific gravity such as an acrylic fiber. It was necessary to use them properly.

In order to eliminate the complexity of using these fibers as much as possible, the cross-sectional shape of the fibers has been improved. Examples of the fibers having improved cross-sectional shapes include, for example, rounded substantially star-shaped or hook-shaped fibers having a cross section close to a circle (see Patent Document 2), and protrusions such as a trident Y-shaped cross section. Have a cross section (see Patent Document 3), and have a C-shaped cross section (see Patent Document 4). Further, a fiber having a hollow cross section formed by 3 to 6 T-shaped protrusions whose cross sections are arranged radially from the center, and each protrusion tip is in contact with the adjacent protrusion tip (see Patent Document 5). Has been proposed.
Furthermore, a fiber having a cross-sectional shape in which three protrusions are formed in order to impart bulkiness and softness (see Patent Document 6) has been proposed. In general, softness is improved in a cross-sectional shape close to a circle, but bulkiness is reduced. Conversely, a hollow or semi-hollow cross-sectional shape or a cross-sectional shape with protrusions improves bulkiness but reduces softness.
JP 11-61555 A JP 55-76102 A Japanese Utility Model Publication No. 58-37961 JP 2003-96618 A Japanese Utility Model Publication No. 63-48652 JP-A-8-296112

  The present invention is a novel artificial hair fiber having a good balance between softness and bulkiness used in the manufacture of hair ornament products such as wigs, hairpieces, blades and extension hairs, a method for producing the same, and a method for producing the same. It is to provide hair decoration products.

As a result of intensive studies to achieve the object, the present inventor has found that specific artificial hair fibers whose cross-sectional shape has been improved can effectively exhibit the advantages as a head decoration product. Further, as the vinyl chloride fiber, it has been found that a fiber obtained by melt spinning a specific ethylene-vinyl chloride copolymer resin can provide a fiber for artificial hair with a low nozzle pressure and less occurrence of eye grease. .
That is, the present invention is based on the above findings, and the gist thereof is as follows.
1. A fiber for artificial hair, wherein the fiber cross section is at least one selected from the group consisting of a U-shape, a Y-shape, a C-shape, and an H-shape.
2. The cross section of the fiber curved in an arc shape has a main body, legs provided on the left and right of the main body, and a foot provided at the tip of the leg, and the longitudinal direction of the fiber. 2. The fiber for artificial hair according to 1 above, which has a hollow portion provided with an opening portion opened in a direction perpendicular to the axis.
3. The cross-section of the fiber is the following formula: 1.4R ₂ ≦ R ₁ ≦ 2.4R ₂ (1)
1 ° ≦ θ ≦ 35 ° (2)
(Where R ₁ is the maximum outer dimension passing through the center of the assumed inscribed circle of the hollow part, R ₂ is the diameter of the assumed inscribed circle of the hollow part, and θ is the assumed inscribed circle of the hollow part. The fiber for artificial hair as described in 2 above, which has a C-shaped shape satisfying the angle of a line segment connecting the center of the C-shaped and two tips of the C-shaped.
4). The fiber cross section has a taper shape in which the thickness width increases toward the tip portion, and the taper shape has the following formula: 1.1 t ₁ ≦ t ₂ ≦ 2.0 t _1. 3)
The fiber for artificial hair according to 3 above, wherein t ₁ is the minimum thickness and t ₂ is the maximum thickness.
5. The cross section of the fiber has a Y-shaped shape having a protruding portion from one central connecting portion to three sides, and at least one of the protruding portions is a length from the center of the central connecting portion to the leading end of the protruding portion. 2. The fiber for artificial hair according to 1 above, which is most swollen at a portion closer to the tip than 1/2 of Ly and is most constricted at a portion closer to the center of the central connecting portion than 1/2 of length Ly.
6. The fiber for artificial hair according to 5 above, wherein the tip of the projecting portion has an arc shape.
7. In the Y-shaped shape, if the width of the most swollen portion of the projecting portion is Wy and the width of the most constricted portion of the projecting portion is Ry, the ratio Wy / Ry Wy / Ry is 1.3 to The fiber for artificial hair according to 5 or 6 above, which is in the range of 2.0.
8. For artificial hair according to any one of 5 to 7 above, in which the angle θy between the three projecting portion tip portions and the center of the central coupling portion in the Y-shaped shape is an equal interval of 120 ° fiber.
9. The fiber cross section has a shape partially overlapped in a state in which a plurality of circular cross-sectional areas are arranged so as to have a bent portion, and the width of the overlapped connecting portion is expressed by the following formula 0.2R ₀ ≦ A ₀ ≦ 1.2R ₀ (4)
(In the formula, R ₀ is the radius of the circular cross-sectional area, and A ₀ is the width of the connecting portion.)
The fiber for artificial hair according to any one of (1) to (8), wherein
10. The fiber for artificial hair according to any one of 1 to 9 above, wherein the single fiber fineness of the fiber for artificial hair is 30 to 100 dtex.
11. 11. The fiber for artificial hair according to any one of 1 to 10 above, wherein the bending stiffness of the fiber for artificial hair according to the KES method is (1.2 to 3.5) × 10 ⁻² N · cm ² .
12 The fiber for artificial hair according to any one of 1 to 11 above, wherein the fiber for working hair is a vinyl chloride fiber.
13. A hair decoration product comprising the artificial hair fiber according to any one of 1 to 12 above.
14 (A) mixing a vinyl chloride resin composition containing a vinyl chloride resin, a hydrotalcite composite heat stabilizer, epoxidized soybean oil, and an ester lubricant with a Henschel mixer or a ribbon blender,
(B) From the spinning mold to the mold temperature, the nozzle shape of the vinyl chloride resin composition is at least one selected from the group consisting of a U shape, a C shape, a Y shape, and an H shape. A step of melt spinning at 160 to 190 ° C.,
(C) a step of stretching the melt-spun fiber to 200 to 400% in an air atmosphere of 90 to 120 ° C, and (d) a total length of the fiber before treatment in an air atmosphere of 110 to 140 ° C on the stretched fiber. The method for producing a fiber for artificial hair according to any one of 1 to 11 above, further comprising a step of heat-relaxing until it contracts to a length of 60 to 100%.

  According to the present invention, it is possible to obtain a fiber for artificial hair that has a good balance between softness and bulkiness in which the nozzle pressure is small during production and the occurrence of eye grease is small.

It is a cross-sectional view of the fiber for artificial hair which shows one Embodiment of this invention. It is a top view of the nozzle for manufacturing the fiber for artificial hair which shows one Embodiment of this invention. It is a cross-sectional view of the conventional fiber for artificial hair. It is a cross-sectional view of another conventional fiber for artificial hair.

It is a cross-sectional view of the fiber for artificial hair which shows one Embodiment of this invention. It is a top view of the nozzle for manufacturing the fiber for artificial hair which shows one Embodiment of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a U-shaped nozzle shape in which a fiber cross-sectional shape is connected to a circular cross-sectional area and an obtained artificial hair fiber according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a C-shaped nozzle shape in which a fiber cross-sectional shape is connected to a circular cross-sectional area and an obtained fiber for artificial hair showing an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a Y-shaped nozzle shape in which the fiber cross-sectional shape of the embodiment of the present invention connects circular cross-sectional areas and the obtained artificial hair fiber. FIG. 2 is a schematic cross-sectional view of an H-shaped nozzle shape in which the cross-sectional shape of a fiber showing one embodiment of the present invention connects circular cross-sectional areas and the obtained fiber for artificial hair. It is the conventional fiber for artificial hairs, and a fiber cross-sectional shape is a schematic sectional drawing of C shape. It is the conventional fiber for artificial hairs, and a fiber cross-sectional shape is a schematic sectional drawing of Y shape. It is the conventional fiber for artificial hairs, and a fiber cross-sectional shape is a schematic sectional drawing of star shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body part 2,3 Leg part 4,5 Foot part 6 Inner wall part 11 Center part 12 Solid area 13 Hollow part 14 Opening part 20 Artificial hair fiber R _{1 The} largest external dimension R which passes along the center of a hollow part assumption inscribed circle R ₂ Diameter of the assumed inscribed circle of the hollow part t ₁ Minimum thickness t ₂ Maximum thickness θ Angle formed by the line connecting the center of the assumed inscribed circle of the hollow part and the two tips of the C type

30 Fiber for Artificial Hair 31 Center of the Central Connection Portion Wy Width of the Most Swelled Part of the Protrusion Ry Width of the Constricted Part of the Protrusion Ly Ly Length from the Center of the Central Connection Part to the Tip of the Protrusion Ay ₁ , Ay ₂ , Ay ₃ Protrusion tip end portion θy Angle between the protrusion and the center of the central coupling portion

A ₀ Joint width R ₀ radius 40 Outer surface 41 Inner surface 42 Starting point 43 Ending point

  FIG. 1-1 is a cross-sectional view of a fiber for artificial hair showing an embodiment of the present invention. 1-2 is a plan view of a nozzle for producing a fiber for artificial hair showing an embodiment of the present invention. FIG. 1-3 is a cross-sectional view of a conventional fiber for artificial hair. 1-4 is a cross-sectional view of another conventional fiber for artificial hair.

  As FIG. 1-1 shows, the fiber 20 for artificial hair of this invention is comprised with a vinyl chloride-type resin composition. And the fiber cross section of the fiber 20 for artificial hair of this invention has a C-shaped shape.

The fiber for artificial hair 20 having a C-shaped fiber cross section has an opening 14 whose fiber cross section is curved in an arc shape and opened in a direction perpendicular to the longitudinal axis of the fiber. It has the hollow part 13 provided. The “hollow portion 13 provided with the opened opening 14” includes a hollow central portion 11 and a solid region 12 that extends around the central portion 11 and defines the inner wall portion 6 that surrounds the central portion 11. A C-shaped cross section is shown. An opening 14 provided on the inner wall 6 side connects the central portion 11 to the outside of the fiber. The opening 14 is narrower than the diameter R ₂ of the hollow inscribed circle centering on the central portion 11 of the hollow portion 13, and thereby, between the central portion 11 of the hollow portion 13 and the outside of the fiber. The throat or stenosis is formed.

  Therefore, the fiber for artificial hair 20 has a fiber cross section curved in an arc shape, and the fiber cross section curved in the arc shape has a main body portion 1 and leg portions 2 provided on the left and right sides of the main body portion 1. , 3 and legs 4, 5 provided at the tips of the legs 2, 3, and a hollow provided with an opening 14 that opens perpendicularly to the longitudinal axis of the fiber A portion 13 is provided.

  Thus, when the artificial hair fiber 20 composed of the vinyl chloride resin composition has a C-shaped cross section, the bulkiness, softness, curling property, and good An artificial hair fiber having a balanced texture can be provided at a low cost.

In the present invention, the C-shaped shape is preferably the following formulas (1) and (2):
1.4R ₂ ≦ R ₁ ≦ 2.4R ₂ (1)
1 ° ≦ θ ≦ 35 ° (2)
(Where R ₁ is the maximum outer dimension passing through the center of the assumed inscribed circle of the hollow part, R ₂ is the diameter of the assumed inscribed circle of the hollow part, and θ is the assumed inscribed circle of the hollow part. And the angle formed by the line segment connecting the C-shaped two tips.).

If R ₁ is less than 1.4 times R ₂ , the thickness becomes small, and the nozzle pressure during melt spinning may increase. On the other hand, if R ₁ is larger than 2.4 times R ₂ , the bulkiness may be reduced. If θ is less than 1 °, the nozzle pressure during melt spinning may increase. On the other hand, if θ is greater than 35 °, there is a risk that the two fibers are interlaced and fused during melt spinning.

  Therefore, as in the present invention, if the C-shaped shape satisfies the above formulas (1) and (2), the nozzle pressure during spinning can be prevented from being increased. Therefore, it is possible to prevent the bulkiness from being lowered and to prevent the two fibers from crossing and fusing at the time of melt spinning. Therefore, the fiber 20 for artificial hair can be manufactured stably.

In the present invention, the C-shaped shape preferably has a tapered shape in which the thickness width increases toward the tip portion, and the tapered shape is expressed by the following formula (3).
1.1t ₁ ≦ t ₂ ≦ 2.0t ₁ (3)
(Where t ₁ is the minimum thickness and t ₂ is the maximum thickness).

If t ₂ is less than 1.1 times t _1, the effect of suppressing the nozzle pressure during melt spinning may be lost. On the other hand, if t ₂ is larger than 2.0 times t ₁ , the minimum thickness portion becomes too thin on the contrary, so that the nozzle pressure during melt spinning may be increased.

  Therefore, as in the present invention, the C-shaped shape preferably has a tapered shape in which the thickness width increases toward the tip portion, and the tapered shape satisfies the above formula (3). If satisfied, the nozzle pressure during spinning can be prevented from being increased. Therefore, the artificial hair fiber 20 can be manufactured more stably.

  FIG. 2-1 is a cross-sectional view of the fiber for artificial hair showing one embodiment of the present invention. FIG. 2-2 is a plan view of a nozzle for producing a fiber for artificial hair showing an embodiment of the present invention.

The artificial hair fiber 30 of the present invention is composed of a vinyl chloride resin composition. And the cross section of the fiber 30 for artificial hair of this invention is a Y-shaped shape which has a protrusion part from one center connection part to three sides. Here, as shown in FIG. 2A, the center of the central connecting portion in the fiber cross section refers to the center 31 of the inscribed circle of the central connecting portion in the fiber cross section, and the tip portion of the protruding portion is the protruding portion. The points Ay _{1 to} Ay ₃ that are farthest from the center 31 of the central connecting portion in FIG.

  At least one of the protrusions is swelled most at a portion closer to the tip than ½ of the length Ly from the center 31 of the central coupling portion to the tip of the protrusion, and more than ½ of the length Ly. The reason for the constriction at the portion near the center of the central connecting portion is to provide bulkiness. Cross-sectional shape swelled most on the center side than 1/2 of length Ly, cross-sectional shape constricted at a portion closer to the tip than 1/2 of length Ly, from the center connecting portion toward the tip of the protruding portion The taper-shaped cross-sectional shape can provide sufficient bulkiness for polypropylene and acrylic fibers with relatively low specific gravity, but is sufficient for polyvinyl chloride fibers with relatively high specific gravity. It is because it cannot be given.

  The tip of the protrusion may be sharp, cornered, or uneven, but an arc shape is preferred. If it is not arcuate, a soft touch may not appear.

The width Wy of the most swollen portion and the width Ry of the most constricted portion of the portion closer to the tip than the most constricted portion of the projecting portion are the center 31 of the central connecting portion and the tips Ay ₁ to Ay _{1 of} each projecting portion. Ay ₃ and the width of each section in the direction perpendicular to the straight line connecting the _Wy 1 _{~Wy 3,} refers to Ry 1 to Ry _3. The ratio Wy / Ry of the width Wy of the most swollen portion of the protrusion and the width Ry of the narrowest portion is preferably 1.3 to 2.0. If Wy / Ry is less than 1.3, bulkiness may not be obtained. On the other hand, if Wy / Ry is larger than 2.0, the balance of the overall size of the fiber cross section is lost, and the width Ry of the most constricted portion becomes extremely thin. For this reason, there is a problem that the fiber is easily broken at the fiber production stage, and the combability may not be achieved.

The length of the three protrusions may be the same or different. Further, the angle θy between the three projecting tip portions and the center 31 of the central connecting portion means that the three straight lines connecting the center 31 of the central connecting portion and the tips Ay _{1 to} Ay _{3 of the} projecting portions are each other. This refers to the angles θy _{1 to} θy ₃ formed. For example, the angle θy ₁ is an angle between straight lines connecting Ay _{1 to} 31 to Ay ₂ . The angles θy _{1 to} θy ₃ are 90 to 140 °, more preferably 110 to 130 °. More preferably, the angles θy _{1 to} θy ₃ between the _three protrusion tip portions Ay _{1 to} Ay ₃ and the center 31 of the central coupling portion are equally spaced by 120 °. When the angles θy _{1 to} θy ₃ are equidistant at 120 °, combability may be good. On the other hand, if any one of the angles θy _{1 to} θy ₃ is smaller than 90 °, the combability may be significantly deteriorated. Furthermore, the cross-sectional shape in which the radius of the circle circumscribing the three protrusion tips is 2 to 4 times the radius of the inscribed circle is preferable. If the radius is smaller than twice the inscribed radius, the bulkiness cannot be obtained, and if it is larger than 4 times, the combing property may be deteriorated.

The fiber for artificial hair of the present invention may have an atypical cross section in which the fiber cross section is partially overlapped in a state where a plurality of circular cross section regions are arranged so as to have a bent portion. By forming a shape in which a plurality of circular cross-sectional areas are partially overlapped, a substantially semicircular convex surface can be continuously formed on the outer and inner surfaces of the fiber cross section, and a soft feel can be obtained.
The outer surface of the fiber cross section represents the 40th surface in FIG. 3-1, and the inner surface represents the 41th surface in FIG. The plurality of circular cross-sectional areas may have different sizes, and the circular cross-sectional area may have an elliptical shape, but is preferably a perfect circle. Further, the center of the overlapping circle or ellipse and the center of the connecting portion may or may not be parallel. Further, the state of being arranged so as to have a bent portion is a state of not being arranged on a straight line, for example, through a gentle arc-shaped bent portion, an acute bent portion, a right angle bent portion, an obtuse bent portion, FIG. 3A shows a state in which the starting point 42 and the ending point 43 are continuously connected. In this way, the fiber cross section has a shape that is partially overlapped with a plurality of circular cross-sectional regions arranged so as to have a bent portion, so that, for example, a texture closer to human hair than a single circular shape is obtained. can get.

When the radius of the circular cross-sectional area is R ₀ , the width A _{0 of the} connecting portion is 0.2R ₀ to 1.2R ₀ . The width A ₀ of the connecting portion is 0.2 R ₀ is smaller than the thickness of the width A ₀ of the connecting portion is reduced, the greater the uneven surface of the surface of the fiber cross-section, the nozzle pressure during melt spinning is increased. On the other hand, the width A ₀ of the connection portion is larger than 1.2R _0, to become smooth the surface of the fiber cross-section, the soft feeling may be lowered.

In the present invention, the U-shaped, C-shaped, Y-shaped, and H-shaped sections may be used as the atypical cross section having a shape partially overlapped with a plurality of circular cross-sectional areas arranged in a curved line. At least one selected from the group consisting of By setting it as the said fiber cross-sectional shape, the fiber for artificial hair excellent in curl uniformity is obtained. These cross-sectional shapes have high symmetry, and have the same fineness, for example, the porosity is relatively higher than that of a single circular shape, so that the rigidity is high and it is suitable for obtaining a more uniform curl property.
The U-shape is a semi-hollow shape that is curved in an arc shape in the cross section of the fiber and has an opening, for example, as shown in FIG. The thickness of the arcuate portion may be the same, changed, or asymmetrical, and the opening end may be rounded or cornered. The width of the opening is preferably the same as the diameter of the hollow center. The number of circular cross-sectional areas is preferably 5 or more.

  The C-shape is a fiber that is curved in an arc shape in the cross section of the fiber and has an “open hollow” cross section perpendicular to the longitudinal axis of the fiber. “Open hollow” refers to a generally C-shaped cross section having a hollow center and a solid region extending around the center and defining a wall portion surrounding the center, The opening on the part side connects the center to the outside of the fiber. The opening is narrower than the diameter of the hollow center, thereby forming a throat or constriction between the hollow center and the outside of the fiber. For example, the shape shown in FIG. The thickness of the arcuate portion may be the same, changed, or asymmetrical, and the opening end may be rounded or cornered. The number of circular cross-sectional areas is preferably 5 or more.

  The Y-shape is a shape having three protrusions radially from the center, for example, the shape shown in FIG. The lengths of the three protrusions may be the same or different. Preferably, the angle θ between the protrusions is 90 to 140 °, more preferably 110 to 130 ° C., and the total angle of the three θs is 360 °. A cross-sectional shape in which the radius of the circle circumscribing is 2 to 4 times the radius of the inscribed circle is preferable. The number of circular cross-sectional areas is preferably 4 or more.

  The H-shape is a shape in which two parallel lines are connected by a single vertical line, for example, the shape shown in FIG. 3-4 and includes an I-shape. The number of circular cross-sectional areas is preferably 5 or more.

  In the present invention, two or more types of atypical cross sections may be mixed, or a hollow body thereof may be used as long as the cross section has a shape in which circular cross-sectional areas are partially overlapped.

The bending rigidity of the artificial hair fiber of the present invention is measured by, for example, the KES method. KES is an abbreviation for Kawabata Evaluation System. The bending stiffness is described by Katsuo Kawabata, Journal of the Textile Machinery Society (Textile Engineering), Vol. 26, no. 10, by the KES method described in P721-P728 (1973), the repulsive force at each curvature when the fiber was bent using a bending property measuring machine (manufactured by Kato Tech Co., Ltd.) was measured. It is the average value of the repulsive force with one fiber between ˜1.5 (cm ⁻¹ ). By measuring the repulsive force of one fiber, the rigidity of the fiber can be predicted.

  The method of controlling the value of the bending stiffness by the KES method is achieved by controlling the mold temperature of the nozzle when melt spinning the fiber. Although the reason is not clear, the bending rigidity can be lowered by lowering the mold temperature of the nozzle. It can also be achieved by changing the fineness of the fiber. By reducing the fineness, the bending rigidity can be lowered. On the other hand, by increasing the fineness, the bending rigidity can be increased. Moreover, even if the fineness is the same, the higher the objectivity of the fiber cross section and the higher the porosity, the higher the bending rigidity.

In the present invention, bending stiffness by KES method ^{fibers, (1.2~3.5) × 10 -2 N} · cm 2 are preferred, especially (1.8~2.5) × ^{10 -2} N · cm ² is preferred. When the bending rigidity is smaller than 1.2 × 10 ⁻² N · cm ² , the curl uniformity may be inferior. On the other hand, if it is larger than 3.5 × 10 ⁻² N · cm ² , the tactile sensation becomes hard and the soft feeling may be lowered.

  In the present invention, synthetic resins used as artificial hair fibers include vinyl chloride resins, modacrylic resins, polyethylene terephthalate resins, polypropylene resins, nylon resins, and other synthetic resins conventionally used for artificial hair fibers, All synthetic resins that can be made into fibers such as polylactic acid and polyvinyl alcohol resin are included. Among these, a vinyl chloride resin is preferable from the characteristics such as strength, gloss, hue, flame retardancy, feel, and heat shrinkability.

  The above-mentioned vinyl chloride resin is obtained by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., but uses the one prepared by suspension polymerization in consideration of the initial colorability of the fiber. It is preferable to do this. The vinyl chloride resin is a homopolymer resin which is a conventionally known homopolymer of vinyl chloride, or various conventionally known copolymer resins, and is not particularly limited. Examples of the copolymer resin include conventionally known copolymer resins of vinyl chloride and vinyl esters such as vinyl chloride-vinyl acetate copolymer resin and vinyl chloride-vinyl propionate copolymer resin; vinyl chloride-butyl acrylate copolymer resin, vinyl chloride. -Copolymer resin of vinyl chloride and acrylates such as 2-ethylhexyl acrylate copolymer resin; Copolymer resin of vinyl chloride and olefins such as vinyl chloride-ethylene copolymer resin, vinyl chloride-propylene copolymer resin; Vinyl chloride-acrylonitrile It is a copolymer resin. The vinyl chloride resin used in the present invention is preferably a homopolymer resin which is a homopolymer of vinyl chloride, a vinyl chloride-ethylene copolymer resin, or a vinyl chloride-vinyl acetate copolymer resin. In the copolymer resin, the content of the comonomer is not particularly limited and can be determined according to the required quality such as moldability and yarn characteristics.

  The vinyl chloride resin used in the present invention is preferably a homopolymer resin which is a homopolymer of vinyl chloride, a vinyl chloride-ethylene copolymer resin, or a vinyl chloride-vinyl acetate copolymer resin. In the copolymer resin, the content of the comonomer is not particularly limited, and can be determined according to required qualities such as moldability and yarn characteristics. The viscosity average polymerization degree of the vinyl chloride resin is preferably 600 to 2500, more preferably 900 to 2500, and particularly preferably 1000 to 2000. It is preferable that If it is less than 600, the melt viscosity is lowered, so that the resulting fiber may be easily heat-shrinked. On the other hand, if it exceeds 2500, the melt viscosity becomes high, so that the fiber molding temperature becomes high and the fiber may be colored. The viscosity average degree of polymerization was calculated according to JIS-K6720-2 by dissolving 200 mg of resin in 50 ml of nitrobenzene, measuring the specific viscosity of this polymer solution in a constant temperature bath at 30 ° C. using an Ubbelohde viscometer. is there.

  Among them, the vinyl chloride fiber is preferably a fiber obtained by melt spinning an ethylene-vinyl chloride copolymer resin having an ethylene content of 0.5 to 3% by mass. Such an ethylene-vinyl chloride copolymer resin is a copolymer resin obtained by a polymerization reaction of a vinyl chloride monomer and an ethylene monomer, and the ethylene content is 0.5 to 3% by mass, preferably 0.8 to 2.5% by mass. If the ethylene content is less than 0.5% by mass, the effect of suppressing nozzle pressure and eye grease cannot be obtained. On the other hand, if it exceeds 3% by mass, the fiber tends to shrink by heat. The ethylene content was based on the GTP-002 method.

  Further, in the present invention, curl retention is added to the fiber by melt spinning a resin composition in which the ethylene-vinyl chloride copolymer resin and the vinyl chloride resin excluding the ethylene-vinyl chloride copolymer resin are mixed. be able to. The proportion of the vinyl chloride resin in the mixed resin is preferably 40% by mass or less. More preferably, 35 mass% or less is good. If the proportion of the vinyl chloride resin exceeds 40% by mass, the effect of suppressing the filling in melt spinning may not be obtained.

  In the vinyl chloride resin composition of the present invention, conventionally known additives used for the vinyl chloride resin composition may be blended depending on the purpose. These additives include heat stabilizers, plasticizers, lubricants, compatibilizers, processing aids, reinforcing agents, UV absorbers, antioxidants, antistatic agents, fillers, flame retardants, pigments, and initial color improvement. Agents, conductivity-imparting agents, surface treatment agents, light stabilizers, and fragrances.

  As the heat stabilizer, for example, one or more selected from heat stabilizers such as a Ca-Zn heat stabilizer, a hydrotalcite heat stabilizer, a tin heat stabilizer, and a zeolite heat stabilizer are selected. Can be used. It is preferable to use a Ca—Zn-based heat stabilizer and a hydrotalcite-based heat stabilizer in combination since the balance between moldability and yarn characteristics is excellent. These heat stabilizers are preferably used at a ratio of 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the vinyl chloride resin.

  Examples of plasticizers include epoxy plasticizers, phthalic acid plasticizers, adipic acid plasticizers, polyester plasticizers, phosphate ester plasticizers, stearic acid plasticizers, trimellitic acid plasticizers, One type or two or more types can be selected from plasticizers such as merit plasticizers. In particular, an epoxy plasticizer having a small influence on the elongation is preferable, and it is preferable to use 0.2 to 3.0 parts by mass with respect to 100 parts by mass of the vinyl chloride resin.

The method for producing a fiber for artificial hair of the present invention preferably includes the following steps (a) to (d).
(A) a step of mixing a vinyl chloride resin composition containing a vinyl chloride resin, a hydrotalcite composite heat stabilizer, an epoxidized soybean oil, and an ester lubricant;
(B) From the spinning mold to the mold temperature, the nozzle shape of the vinyl chloride resin composition is at least one selected from the group consisting of a U shape, a C shape, a Y shape, and an H shape. A step of melt spinning at 160 to 190 ° C.,
(C) a step of stretching the melt-spun fiber to 200 to 400% in an air atmosphere of 90 to 120 ° C., and (d) a total length of the fiber before treatment in an air atmosphere of 110 to 140 ° C. Heat relaxation treatment until it contracts to a length of 60-100%.

  When the steps (a) to (d) as described above are sequentially provided, a fiber for artificial hair having a good balance between softness and bulkiness can be stably produced.

In the production of the artificial hair fiber of the present invention, the raw material resin composition is a powder compound obtained by mixing using a conventionally known mixer such as a Henschel mixer, a super mixer, a ribbon blender, or the like. It can be used as a melt-mixed pellet compound. The powder compound can be produced by conventional conditions known in the art, that is, hot blending and cold blending. The hot blend is particularly preferably formed by raising the cut temperature during blending to 105 to 155 ° C. because it reduces the volatile content in the resin composition.
The pellet compound can be produced in the same manner as a normal vinyl chloride pellet compound. Such a pellet compound is, for example, a kneader such as a single screw extruder, a different direction twin screw extruder, a same direction twin screw extruder, a conical ni screw extruder, a kneader, a planetary gear extruder, a roll kneader or the like. Manufactured by using Conditions for producing such a pellet compound are not particularly limited, but preferably the resin temperature is set to 185 ° C. or lower.

The fiber for artificial hair of the present invention is preferably processed by melt spinning, and the nozzle used is a cross-sectional shape due to expansion due to the ballast effect when the molten resin is extruded from the nozzle and / or stretching applied to the fiber during spinning. What is necessary is just to select suitably by reduction etc. In particular, in the case of melt spinning, a polyvinyl chloride resin has good formability. Therefore, an appropriate artificial hair fiber can be obtained by using a nozzle having a hole shape substantially similar to the cross-sectional shape of the target fiber of the present invention. Considering the quality aspects such as curling characteristics for artificial hair, it is preferable that the cross-sectional area of one nozzle hole is melted and discharged from a nozzle having a size of 0.5 mm ² or less. When the cross-sectional area of one nozzle hole exceeds 0.5 mm ² , it is necessary to apply excessive tension in order to obtain an unstretched yarn or a heated yarn with a fineness, which increases the residual strain. Quality such as curl retention may be degraded. Therefore, in the production of the fiber for artificial hair of the present invention, the vinyl chloride resin composition is preferably formed from a plurality of nozzle holes of a multi-type nozzle having a cross-sectional area of one nozzle hole of 0.5 mm ² or less. It is melted and flowed out to form a strand, which is an undrawn yarn of 300 dtex or less.

  The pellet compound and the like of the vinyl chloride resin composition are melt-spun at a temperature of 160 to 190 ° C. using, for example, a single-screw extruder to obtain an undrawn yarn. The undrawn yarn thus obtained is preferably drawn to 200 to 400% in an air atmosphere of 90 to 120 ° C., and the total fiber length is 60 before treatment in an air atmosphere of 110 to 140 ° C. Thermal relaxation treatment until shrinking to -100% length.

  The unstretched yarn is subjected to a stretching treatment and a heat treatment, and the single fineness thereof is preferably 20 to 100 dtex, and more preferably 50 to 80 dtex. When it is 20 to 100 dtex, the hair is not inferior to natural hair, and when it is 50 to 80 dtex, the touch and texture are further improved.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited to the examples.

(Example 1-1)
(A) 100 parts by mass of a vinyl chloride resin (manufactured by Taiyo PVC Co., TH-1000), 3 parts by mass of a hydrotalcite-based composite heat stabilizer (manufactured by Nissan Chemical Industries, CP-410A) (the heat stabilizer component is 1 0.5 parts by mass), 0.5 parts by mass of epoxidized soybean oil (Asahi Denka Kogyo Co., Ltd., O-130P), and 0.8 parts by mass of an ester lubricant (manufactured by Riken Vitamin Co., Ltd., EW-100). Mixing a vinyl chloride resin composition with a Henschel mixer;
(B) A spinning mold having a nozzle cross-sectional area of 0.06 mm ² and a nozzle hole number of 120, having a C-shaped nozzle shape as shown in FIG. , A process of forming 150 decitex fibers by melt spinning at a mold temperature of 180 ° C. and an extrusion rate of 10 kg / hour,
(C) stretching the melt-spun fiber to 300% in an air atmosphere at 100 ° C., and
(D) The stretched fiber is successively subjected to a relaxation treatment in an air atmosphere at 120 ° C. until the total length of the fiber shrinks to 75% of the length before the treatment, and the C-shaped fiber shown in FIG. A fiber for artificial hair having a fineness of 67 dtex having a cross-sectional shape of R ₁ : 100 μm, R ₂ : 60 μm, θ: 20 degrees, t ₁ : 20 μm and t ₂ : 35 μm was obtained.

(Example 1-2)
By changing the nozzle shape in the step (b) of Example 1-1, the C-shaped fiber cross-sectional shape was R ₁ : 100 μm, R ₂ : 70 μm, θ: 30 degrees, t ₁ : 15 μm, and t _2. : A fiber for artificial hair was obtained in the same manner as in Example 1-1 except that 67 dtex fiber for artificial hair of 20 μm was obtained.

(Example 1-3)
By changing the nozzle shape in the step (b) of Example 1-1, the cross-sectional shape of the C-shaped fiber is R ₁ : 100 μm, R ₂ : 60 μm, θ: 5 degrees, t ₁ : 20 μm, and t _2. : A fiber for artificial hair was obtained in the same manner as in Example 1-1 except that 67 dtex fiber for artificial hair of 20 μm was obtained.

(Example 1-4)
By changing the nozzle shape in the step (b) of Example 1-1, the C-shaped fiber cross-sectional shape was R ₁ : 100 μm, R ₂ : 80 μm, θ: 20 degrees, t ₁ : 10 μm, and t _2. : A fiber for artificial hair was obtained in the same manner as in Example 1-1 except that 67 dtex fiber for artificial hair of 15 μm was obtained.

(Example 1-5)
By changing the nozzle shape in step (b) of Example 1-1, the C-shaped fiber cross-sectional shape was R ₁ : 100 μm, R ₂ : 40 μm, θ: 20 degrees, t ₁ : 30 μm, and t _2. : A fiber for artificial hair was obtained in the same manner as in Example 1-1 except that 67 dtex fiber for artificial hair of 35 μm was obtained.

(Example 1-6)
By changing the nozzle shape in the step (b) of Example 1-1, the C-shaped fiber cross-sectional shape was R ₁ : 100 μm, R ₂ : 60 μm, θ: 0.5 degree, t ₁ : 20 μm, and Artificial hair fibers were obtained in the same manner as in Example 1-1 except that 67 dtex artificial hair fibers having t _{2 of} 25 μm were obtained.

(Example 1-7)
The nozzle shape in the step (b) of Example 1-1 was changed so that the C-shaped fiber cross-sectional shape was R ₁ : 100 μm, R ₂ : 60 μm, θ: 40 degrees, t ₁ : 20 μm, and t _2. : A fiber for artificial hair was obtained in the same manner as in Example 1-1, except that 67 dtex fiber for artificial hair of 25 μm was obtained.

(Example 1-8)
The nozzle shape in the step (b) of Example 1-1 was changed so that the C-shaped fiber cross-sectional shape was R ₁ : 100 μm, R ₂ : 60 μm, θ: 20 degrees, t ₁ : 20 μm, and t _2. : A fiber for artificial hair was obtained in the same manner as in Example 1-1 except that 22 dtex fiber for artificial hair of 25 μm was obtained.

(Example 1-9)
The nozzle shape in the step (b) of Example 1-1 was changed so that the C-shaped fiber cross-sectional shape was R ₁ : 100 μm, R ₂ : 60 μm, θ: 20 degrees, t ₁ : 20 μm, and t _2. : A fiber for artificial hair was obtained in the same manner as in Example 1-1 except that 120 dtex fiber for artificial hair having a diameter of 20 μm was obtained.

(Comparative Example 1-1)
The nozzle shape in the step (b) of Example 1-1 was changed to a Y shape, and 67 dtex fiber for artificial hair having the conventional Y shape fiber cross-sectional shape shown in FIG. 1-4 was obtained. Except that, artificial hair fibers were obtained in the same manner as in Example 1-1.

(Comparative Example 1-2)
The nozzle shape in the step (b) of Example 1-1 was changed to a saddle shape to obtain 67 dtex fiber for artificial hair having the conventional saddle shape fiber cross-sectional shape shown in FIG. 1-3. Obtained the fiber for artificial hair like Example 1-1.

As described above, the specific volume, curl uniformity, curl retention, bending rigidity, and fusion of the artificial hair fibers obtained in Examples 1-1 to 1-9 and Comparative Examples 1-1 to 1-2 were evaluated. Moreover, the nozzle pressure in Examples 1-1 to 1-9 and Comparative Examples 1-1 to 1-2 was evaluated. The evaluation results are shown in Table 1-1.
The contents and evaluation criteria of these items were as follows.

“Specific volume” is an index of the bulkiness of a fiber. “Specific volume” is a 56 cc container (100 mm × 14 mm × 40 mm) filled with fibers cut to 100 mm until the container is full, then the filled fibers are taken out and the fiber weight is weighed, The following formula: Volume of container (cc) / fiber weight (g) = specific volume (cc / g)
And calculated from the fiber weight. The results were evaluated according to the following criteria.
Excellent: The specific volume is 2.0 (cc / g) or more and very bulky. Good: The specific volume is 1.7 to 2.0 (cc / g), and the bulk is large. Defect: Specific volume is less than 1.7 (cc / g) and low bulkiness

The “curl uniformity” was evaluated as follows. That is, a fiber bundle having a length of 60 cm and 1 g is wound around a 30 mm length of Φ30 mm aluminum pipe, heated at 85 ° C. for 1 hour, and then left for 2 hours under constant temperature conditions (20 ° C., 65 RH%). After curling, the fiber bundle with the curling was removed from the pipe and hung, and the distance between the first and fifth curling pitches from the top 24 hours after the hanging was measured. " The results were evaluated according to the following criteria.
Excellent: The difference between curl pitches is less than 10 mm and suitable for products that require tight curls. Good: The difference between curl pitches is 10 to 20 mm, and a uniform curl is obtained. Bad: Curl pitch The difference between them is larger than 20mm, and uniform curl cannot be obtained

  “Curl retention” was evaluated in the same manner as shown in Table 1-3. The shorter the moving distance of the tip, the better the curl retention.

“Bending stiffness” is an index of tactile feel of the fiber. For the measurement of “bending rigidity” in the present invention, a pure bending tester (KES-FB2, manufactured by Kato Tech Co., Ltd.) was used. The “bending rigidity” in the present invention is obtained by passing one fiber having a length of 9 cm through a jig having a diameter of 0.2 μm, and 0.2 (cm ⁻¹ ) in a curvature range of −2.5 to +2.5 (cm ⁻¹ ). ) Was subjected to a pure bending test, and the average value of the repulsive force of one fiber with a curvature of 0.5 to 1.5 (cm ⁻¹ ) was measured and evaluated according to the following criteria.
Good: Flexural rigidity is (1.2 to 3.5) × 10 ⁻² N · cm ² , and the fiber has moderate stiffness and is preferable as a fiber for artificial hair. Bad: Flexural rigidity is 1.2 × 10. ^{It is} less than ^-2 N · cm ² and there is no softness of the fiber, or it has a soft tactile sensation, or the bending stiffness is 3.5 × 10 ^-2 N · cm ² or more and the stiffness of the fiber becomes strong. Unpleasant texture for artificial hair due to the harsh feel

“Fusion” means that two fibers are interlaced at the time of melt spinning to form one thick yarn. “Fusion” in the present invention was evaluated based on the following criteria by observing the spun yarn and measuring the number of fused yarns.
Good: No fusing, no quality problems Bad: One or more fusing, quality problems

  “Nozzle pressure” was evaluated in the same manner as shown in Table 4-1.

(Example 2-1)
(A) 100 parts by mass of a vinyl chloride resin (manufactured by Taiyo PVC Co., TH-1000), 3 parts by mass of a hydrotalcite-based composite heat stabilizer (manufactured by Nissan Chemical Industries, CP-410A) (the heat stabilizer component is 1 .5 parts by mass), 0.5 parts by mass of epoxidized soybean oil (O-130P manufactured by Asahi Denka Kogyo Co., Ltd.) and 0.8 parts by mass of an ester lubricant (EW-100 manufactured by Riken Vitamin Co., Ltd.). Mixing the composition with a Henschel mixer,
The (b) the mixed resin composition, having a Y-shaped nozzle shape as shown in Figure 2-2, using a spinning die nozzle cross-sectional area 0.06 mm ² nozzle hole number 120, a mold temperature of 185 A step of melt spinning at 150 ° C. and an extrusion rate of 15 kg / hour to form 150 dtex fiber,
(C) stretching the melt-spun fiber to 300% in an air atmosphere at 100 ° C.,
And
(D) The stretched fiber is sequentially subjected to a thermal relaxation treatment in an air atmosphere at 130 ° C. until the total length of the fiber shrinks to 75% of the length before the treatment, and one central connection shown in FIG. Y-shaped fiber cross-sectional shape having protrusions in three directions from the portion, at least one of the protrusions is a portion close to the tip where the length Ly from the center 31 of the central connecting portion to the tip of the protrusion is 0.73 And has a maximum constriction at a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly, and further, the tip end shape of the protruding portion is an arc shape, and the Wy / Ry ratio is 1.6. A 67 dtex fiber for artificial hair was obtained.

(Example 2-2)
The nozzle shape in the step (b) of Example 2-1 is changed, and a Y-shaped fiber cross-sectional shape having a protruding portion from one central connecting portion in three directions is such that at least one of the protruding portions is the center of the central connecting portion. There is a maximum bulge in a portion close to the tip where the length Ly is 0.95 from 31 to the tip of the projecting portion, and a maximum is in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly. A 67 dtex fiber for artificial hair with a constriction, an arc shape at the tip of the protrusion, and a Wy / Ry ratio of 1.7 was obtained.

(Example 2-3)
The nozzle shape in the step (b) of Example 2-1 is changed, and a Y-shaped fiber cross-sectional shape having a protruding portion from one central connecting portion in three directions is such that at least one of the protruding portions is the center of the central connecting portion. There is a maximum bulge in a portion close to the tip where the length Ly is 0.73 from 31 to the tip of the protrusion, and the maximum is in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly. A 67 dtex fiber for artificial hair having a constriction, an angular shape at the tip of the protruding portion, and a Wy / Ry ratio of 1.7 was obtained.

(Example 2-4)
By changing the nozzle shape in the step (b) of Example 2-1, the Y-shaped fiber cross-sectional shape is such that at least one of the protrusions is a length L from the center 31 of the central coupling part to the tip of the protrusion. There is a maximum bulge in the portion close to the tip of 0.73, and there is a maximum constriction in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly, and the tip of the protruding portion is arcuate, A 67 dtex artificial hair fiber having a Wy / Ry ratio of 1.1 was obtained.

(Example 2-5)
By changing the nozzle shape in the step (b) of Example 2-1, the Y-shaped fiber cross-sectional shape is such that at least one of the protrusions is the length Ly from the center 31 of the central connecting part to the tip of the protrusion. There is a maximum bulge in the portion close to the tip of 0.73, and there is a maximum constriction in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly, and the tip of the protruding portion is arcuate, A 67 dtex fiber for artificial hair having a Wy / Ry ratio of 2.4 was obtained.

(Example 2-6)
By changing the nozzle shape in the step (b) of Example 2-1, the Y-shaped fiber cross-sectional shape is such that at least one of the protrusions is the length Ly from the center 31 of the central connecting part to the tip of the protrusion. There is a maximum bulge in the portion close to the tip of 0.73, and there is a maximum constriction in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly, and the tip of the protruding portion is arcuate, A 22 dtex fiber for artificial hair having a Wy / Ry ratio of 1.6 was obtained.

(Example 2-7)
By changing the nozzle shape in the step (b) of Example 2-1, the Y-shaped fiber cross-sectional shape is such that at least one of the protrusions is the length Ly from the center 31 of the central connecting part to the tip of the protrusion. There is a maximum bulge in the portion close to the tip of 0.73, and there is a maximum constriction in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly, and the tip of the protruding portion is arcuate, A 120 dtex artificial hair fiber having a Wy / Ry ratio of 1.6 was obtained.

(Comparative Example 2-1)
By changing the nozzle shape in the step (b) of Example 2-1, the Y-shaped fiber cross-sectional shape is such that at least one of the protrusions is the length Ly from the center 31 of the central connecting part to the tip of the protrusion. There is a maximum bulge in the portion close to the central connecting portion of 0.35, and there is a maximum constriction in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly, and the tip shape of the protruding portion is a circle. A 67 dtex artificial hair fiber having an arc shape and a Wy / Ry ratio of 1.6 was obtained.

(Comparative Example 2-2)
By changing the nozzle shape in the step (b) of Example 2-1, the Y-shaped fiber cross-sectional shape is such that at least one of the protrusions is the length Ly from the center 31 of the central connecting part to the tip of the protrusion. There is a maximum bulge in the portion close to the tip of 0.73, and there is a maximum constriction in a portion closer to the center 31 of the central connecting portion than 1/2 of the length Ly, and the tip of the protruding portion is arcuate, A 67 dtex artificial hair fiber having a Wy / Ry ratio of 1.6 was obtained.

(Comparative Example 2-3)
The nozzle shape in the step (b) of Example 2-1 was changed to a saddle shape, and a 67 dtex artificial hair fiber having a conventional saddle-shaped fiber cross-sectional shape shown in FIG. 1-3 was obtained. In the same manner as in Example 2-1, a fiber for artificial hair was obtained.

  As described above, the combing property, soft feeling and bulkiness of the fibers for artificial hair obtained in Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-3 were evaluated. The results are shown in Table 2-1. The contents and evaluation criteria of these items were as follows.

The “combability” in Table 2-1 was evaluated based on the following criteria by measuring the number of catches by passing a comb of 1200 fiber bundles 30 cm in depth 25 mm and a gap interval 2 mm.
Excellent: The number of catches is 0 to 1 and the combing property is very good. Good: The number of catches is 2 to 3 and the combing property is good. Bad: The number of catches is 4 or more. That have poor combability

The “soft feeling” in Table 2-1 was obtained by bundling 24,000 fibers according to the judgment of 10 wig treatment engineers (practical experience 5 years or more), and the touch feeling was evaluated according to the following criteria.
Excellent: A thing that feels soft like natural hair Good: A thing that feels somewhat soft like natural hair Bad: A thing that feels stiff and hard

  The “specific volume” in Table 2-1 was calculated and evaluated in the same manner as shown in Table 1-1.

  As can be seen from Table 2-1, according to the present invention, it is possible to easily obtain a fiber for artificial hair having a good balance of combing property, soft feeling and bulkiness (specific volume).

(Example 3-1)
(A) 100 parts by mass of a vinyl chloride resin (manufactured by Taiyo PVC Co., TH-1000), 3 parts by mass of a hydrotalcite composite thermal stabilizer (manufactured by Nissan Chemical Industries, CP-410A) (the thermal stabilizer component is 1.5 Parts by weight), 0.5 parts by weight of epoxidized soybean oil (O-130P manufactured by Asahi Denka Kogyo Co., Ltd.), and 0.8 parts by weight of an ester lubricant (EW-100 manufactured by Riken Vitamin Co., Ltd.). (B) Spinning with the mixed resin composition having a U-shaped nozzle shape as shown in FIG. 3-1, a nozzle cross-sectional area of 0.06 mm ² and a nozzle hole number of 120 Using a mold, melt spinning at a mold temperature of 185 ° C. and an extrusion rate of 15 kg / hour to form 150 dtex fiber, (c) stretching the melt-spun fiber to 300% in an air atmosphere at 100 ° C. You And (d) a step of heat-relaxing the stretched fiber in an air atmosphere at 130 ° C. until the total length of the fiber contracts to 75% of the length before the treatment, and is shown in FIG. 3-1. A fiber for artificial hair having a U-shaped fiber cross-sectional shape and a fineness of 67 dtex was obtained, in which the width A ₀ of the connecting portion of the circular cross-sectional area was 1.0R ₀ .

(Example 3-2)
By changing the nozzle geometry of the (b) step of Example 3-1, the C-shaped fiber cross-sectional shape shown in Figure 3-2, the width A ₀ of the connecting portion of the circular cross section area, 1.0R _0, it is to give a 67 dtex of fiber for artificial hair.

(Example 3-3)
By changing the nozzle shape in step (b) of Example 3-1, the Y-shaped fiber cross-sectional shape shown in FIG. 3-3 has a width A ₀ of the connecting portion of the circular cross-sectional area of 0.2R. _0, it is to give a 67 dtex of fiber for artificial hair.

(Example 3-4)
Change the step (b) of the nozzle shape of the embodiment 3-1, the H-shaped fiber cross-sectional shape shown in Figure 3-4, the width A ₀ of the connecting portion of the circular cross section area, 0.4R _0, it is to give a 67 dtex of fiber for artificial hair.

(Comparative Example 3-1)
The nozzle shape in the step (b) of Example 3-1 was changed, and the U-shaped fiber cross-sectional shape shown in FIG. 3A was such that the width A ₀ of the connecting portion of the circular cross-sectional area was 1.5R. _0, it is to give a 67 dtex of fiber for artificial hair.

(Comparative Example 3-2)
The nozzle shape in the step (b) of Example 3-1 is changed to a C shape without a circular cross-sectional area, and 67 dtex artificial having the conventional C-shaped fiber cross-sectional shape shown in FIG. 3-5 Except for obtaining hair fibers, artificial hair fibers were obtained in the same manner as in Example 3-1.

(Comparative Example 3-3)
67 dtex artificial having the conventional Y-shaped fiber cross-sectional shape shown in FIG. 3-6 by changing the nozzle shape in the step (b) of Example 3-1 to a Y-shape without a circular cross-sectional area. Except for obtaining hair fibers, artificial hair fibers were obtained in the same manner as in Example 3-1.

(Comparative Example 3-4)
For the 67 dtex artificial hair having the conventional star-shaped fiber cross-sectional shape shown in FIG. 3-7 by changing the nozzle shape in the step (b) of Example 3-1 to a star shape without a circular cross-sectional area. An artificial hair fiber was obtained in the same manner as in Example 3-1, except that the fiber was obtained.

  As described above, the bulkiness, soft feeling, nozzle pressure and curl uniformity of the fibers for artificial hair obtained in Examples 3-1 to 3-4 and Comparative Examples 3-1 to 3-4 were evaluated. The evaluation results are shown in Table 3-1. The contents and evaluation criteria of these items were as follows.

  The “specific volume” in Table 3-1 was calculated and evaluated in the same manner as shown in Table 1-1.

  The “soft feeling” in Table 3-1 was evaluated in the same manner as shown in Table 2-1.

  “Nozzle pressure” in Table 3-1 was measured and evaluated in the same manner as shown in Table 4-1.

  “Curl uniformity” in Table 3-1 was measured and evaluated in the same manner as shown in Table 1-1.

The “bending rigidity” in Table 3-1 was measured using a KES-FB2 pure bending tester (manufactured by Kato Tech). That is, deformation rate of the single fiber length 9cm fibers, through a jig having a diameter 0.2 mm, 0.2 in the range of curvature ^{-2.5~ + 2.5 (cm -1) (} cm -1) Was subjected to a pure bending test, and the average value of the repulsive force of one fiber with a curvature of 0.5 to 1.5 (cm ⁻¹ ) was measured.
“Bending stiffness” is an index of tactile feel of the fiber.

  As is apparent from Table 3-1, according to the present invention, an artificial material having the characteristics of soft feeling, bulkiness (specific volume), and curl uniformity in a well-balanced manner, and also has a low nozzle pressure during melt spinning. It turns out that the fiber for hair is obtained easily.

In Table 4-1, “nozzle pressure” is an index of whether or not spinning can be performed in a stable state for a long time when continuous spinning is performed. “Nozzle pressure” is a measurement of the resin pressure at the nozzle when continuously spinning for 24 hours, and was evaluated according to the following criteria.
Excellent: Nozzle pressure is 40 MPa or less, stable production is possible, and there is no problem in long run properties.
Good: Nozzle pressure is 40 MPa to 45 MPa or less, stable production is possible, and there is no problem in long run properties.
Defect: The nozzle pressure exceeds 45 MPa, and in order to produce stably, it is necessary to reduce the extrusion amount, and there is a problem in the long run property.

In Tables 4-1 and 4-3, the “grease time” is an index of production time until thread breakage occurs due to occurrence of eye grease, production becomes difficult, and the eye grease is wiped off. The “grease time” was evaluated according to the following criteria.
Excellent: 36 hours or more, stable production, no long run problem.
Good: 24 to 36 hours, stable production, no problem in long run properties.
Defect: Less than 24 hours, and there is a problem in long run property for stable production.

In Tables 4-2 and 4-4, “coloring” means that the color of the fiber immediately after continuous spinning was confirmed by visual observation, and was evaluated according to the following criteria.
Excellent: No yellowing and no problem in quality.
Good: Slight yellowing but no problem in quality.
Defect: There is yellowing and there is a quality problem.

In Table 4-3, “curl retention” means that the fiber is wrapped around an aluminum pipe and the tip is fixed, and then placed in a hot air dryer under 90 ° C. for 60 minutes, and then taken out and the temperature is 23 ° C. and the humidity is 50%. It was hung for 24 hours in the state, the moving distance of the suspended tip before and after that was measured, and evaluated according to the following criteria. The shorter the moving distance, the better the curl retention.
Excellent: The moving distance of the tip is 1.5 cm or less.
Good: The moving distance of the tip is 1.5 cm or more and less than 3.0 cm.
Defect: The moving distance of the tip is 3.0 cm or more.

In Tables 4-1, 4-2, and 4-4, “thermal contraction” refers to the thermal contraction rate that occurs when the specimen is heat-treated. The heat shrinkability test is performed by heat-treating a specimen adjusted to a length of 100 mm in a gear oven at 90 ° C. for 15 minutes, and measuring and measuring the length of the specimen before and after the heat treatment. The thermal contraction rate is obtained from the obtained length by the following formula.
Thermal shrinkage (%) = (difference in length of specimen before and after heat treatment) / length of specimen before heat treatment × 100
The number of test specimens was 10 and the average value was evaluated according to the following criteria.
Excellent: The average value of heat shrinkage is 5% or less, and there is no problem in quality.
Good: The average value of the heat shrinkage rate is 5% or more and less than 10%, and there is no problem in quality.
Poor: The average value of the heat shrinkage rate is 10% or more, and there is a problem in quality.

(Example 4-1)
(A) 100 parts by mass of an ethylene-vinyl chloride copolymer resin (manufactured by Taiyo PVC Co., TE-1300: ethylene content 1.5% by mass, degree of polymerization 1300), hydrotalcite-based composite heat stabilizer (Nissan Chemical Industries) CP-410A, 8 parts by mass (4 parts by mass of heat stabilizer component), and 1 part by mass of epoxidized soybean oil (Asahi Denka Kogyo Co., Ltd., O-130P) A step of mixing with a Henschel mixer; (b) melt-spinning the mixed resin composition from a spinning die having a nozzle cross-sectional area of 0.06 mm ² , a hole number of 120 and a die temperature of 180 ° C. at an extrusion rate of 12 kg / hour; (C) a step of drawing the melt-spun fiber to 300% in an air atmosphere at 100 ° C. to make a fiber of 50 dtex, and (d) the drawn fiber. The fibers were successively subjected to a thermal relaxation treatment in an air atmosphere at 120 ° C. until the full length of the fiber shrunk to 75% of that before treatment, to obtain a fiber for artificial hair having a fineness of 67 dtex.

(Examples 4-2 and 4-3, Comparative examples 4-1 and 4-2)
The artificial hair fibers having the ethylene content shown in Table 4-1 were obtained in the same manner as in Example 4-1.

(Examples 4-4 and 4-5)
The ethylene content is 1.5 times that of Example 4-1, and the fibers for artificial hair having the viscosity-average polymerization degree of the ethylene-vinyl chloride copolymer shown in Table 4-2 are the same as Example 4-1. Obtained similarly.

(Examples 4-6 and 4-7)
The artificial hair fibers having the vinyl chloride resin content shown in Table 4-3 were obtained in the same manner as in Example 4-1.

(Examples 4-8 and 4-9)
The content of the vinyl chloride resin is the same as in Example 4-6, and the artificial hair fibers having the viscosity average polymerization degree of the vinyl chloride resin shown in Table 4-4 are the same as in Example 4-1. Obtained.

  The fiber for artificial hair of the present invention has a low nozzle pressure, little generation of eye grease, can be produced stably, and has excellent curl retention.

The vinyl chloride fiber obtained by using the composition of the present invention can be suitably used for artificial hair fibers for hair decoration such as wigs, hairpieces, blades, extension hairs and the like.

In addition, Japanese Patent Application No. 2005-176083 filed on June 16, 2005, Japanese Patent Application No. 2005- 211625 filed on July 21, 2005, Japanese Patent Application filed on August 10, 2005. The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2005-231657 and Japanese Patent Application No. 2005-269975 filed on September 16, 2005 are incorporated herein by reference. It is incorporated as disclosure of the document.

Claims (14)

  A fiber for artificial hair whose fiber cross section is at least one selected from the group consisting of a U-shape, a Y-shape, a C-shape, and an H-shape.   The cross section of the fiber curved in an arc shape has a main body, legs provided on the left and right of the main body, and a foot provided at the tip of the leg, and the longitudinal direction of the fiber. The fiber for artificial hair according to claim 1, which has a hollow portion provided with an opening portion opened in a direction perpendicular to the axis. The cross-section of the fiber is the following formula: 1.4R ₂ ≦ R ₁ ≦ 2.4R ₂ (1)
1 ° ≦ θ ≦ 35 ° (2)
(Where R ₁ is the maximum outer dimension passing through the center of the assumed inscribed circle of the hollow part, R ₂ is the diameter of the assumed inscribed circle of the hollow part, and θ is the assumed inscribed circle of the hollow part. The fiber for artificial hair according to claim 1 or 2, wherein the fiber is a C-shaped shape satisfying the angle formed by a line segment connecting the center of the two and the two C-shaped tips. The fiber cross section has a taper shape in which the thickness width increases toward the tip portion, and the taper shape has the following formula: 1.1 t ₁ ≦ t ₂ ≦ 2.0 t _1. 3)
(Wherein, t ₁ is the minimum thickness, and, t ₂ is the maximum thickness.) Fibers for artificial hair according to claim 1 comprising satisfied.   The cross section of the fiber is a Y-shaped shape having a protruding portion from one central connecting portion to three sides, and at least one of the protruding portions has a length Ly from the center of the central connecting portion to the leading end of the protruding portion. The artificial hair fiber according to claim 1, wherein the fiber is most swelled at a portion closer to the tip than ½, and is most constricted at a portion closer to the center of the central connecting portion than ½ of the length Ly.   The artificial hair fiber according to claim 5, wherein the tip of the protruding portion has an arc shape.   In the Y-shaped shape, if the width of the most swollen portion of the protrusion is Wy and the width of the constricted portion of the protrusion is Ry, the ratio Wy / Ry of Wy to Ry is 1.3-2. The fiber for artificial hair according to claim 5 or 6, wherein the range is 0.   The fiber for artificial hair according to any one of claims 5 to 7, wherein in the Y-shaped shape, the angles θy between the tip portions of the three protruding portions and the center of the central connecting portion are equal intervals of 120 °. . The fiber cross section is a shape partially overlapped in a state where a plurality of circular cross-sectional areas are arranged so as to have a bent portion, and the width of the overlapped connecting portion is expressed by the following formula 0.2R ₀ ≦ A ₀ ≦ 1.2R ₀ (4)
(In the formula, R ₀ is the radius of the circular cross-sectional area, and A ₀ is the width of the connecting portion.)
The fiber for artificial hair according to any one of claims 1 to 8, which satisfies:   The fiber for artificial hair according to any one of claims 1 to 9, wherein the fiber for artificial hair has a single fineness of 30 to 100 dtex. Fiber for artificial hair according to claim 1 flexural rigidity by KES method (1.2 to 3.5) is a × ¹⁰ -2 N · cm ² of the fiber for artificial hair.   The artificial hair fiber according to any one of claims 1 to 11, wherein the artificial hair fiber is a vinyl chloride fiber.   A hair ornament product comprising the fiber for artificial hair according to any one of claims 1 to 12. (A) mixing a vinyl chloride resin composition containing a vinyl chloride resin, a hydrotalcite composite heat stabilizer, epoxidized soybean oil, and an ester lubricant with a Henschel mixer or a ribbon blender,
(B) From the spinning mold to the mold temperature, the nozzle shape of the vinyl chloride resin composition is at least one selected from the group consisting of a U shape, a C shape, a Y shape, and an H shape. A step of melt spinning at 160 to 190 ° C.,
(C) a step of stretching the melt-spun fiber to 200 to 400% in an air atmosphere of 90 to 120 ° C, and (d) a total length of the fiber before treatment in an air atmosphere of 110 to 140 ° C on the stretched fiber. The method of manufacturing the fiber for artificial hair in any one of Claims 1-11 which has the process of heat-relaxing until it shrink | contracts to 60-100% of length of these.

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