JPWO2020170921A1 - Fiber for artificial hair - Google Patents

Abstract

Provided is an artificial hair fiber having excellent productivity and flame retardancy and having suppressed color unevenness. According to the present invention, 100 parts by mass of a polyamide contains 5 to 40 parts by mass of a bromine-based flame retardant and 0.01 to 10 parts by mass of a processing pigment, and the processing pigment contains a colorant and a dispersant. Assuming that the total of the colorant and the dispersant is 100% by mass, the dispersant is 20 to 80% by mass, and the dispersant is 1 of a montanic acid metal salt, a montanic acid wax, a polyethylene wax, and a fluorine wax. Fibers for artificial hair, which are more than seeds, are provided.

Description

The present invention relates to fibers used for artificial hair such as wigs, hair wigs, and hair attachments that can be attached to and detached from the head (hereinafter, simply referred to as "fibers for artificial hair").

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

Japanese Unexamined Patent Publication No. 2011-246844

By the way, a coloring agent such as black or red may be added to the artificial hair fiber for coloring, but the dispersibility of the coloring agent in the polyamide may not be sufficient, and in that case, extrusion is performed. When the resin composition is fiberized using a machine, yarn breakage and clogging of the filter of the extruder may occur frequently, resulting in a decrease in productivity.

The present invention has been made in view of such circumstances, and provides a fiber for artificial hair which is excellent in productivity and flame retardancy and has suppressed color unevenness.

According to the present invention, 100 parts by mass of a polyamide contains 5 to 40 parts by mass of a bromine-based flame retardant and 0.01 to 10 parts by mass of a processing pigment, and the processing pigment contains a colorant and a dispersant. Assuming that the total of the colorant and the dispersant is 100% by mass, the dispersant is 20 to 80% by mass, and the dispersant is 1 of a montanic acid metal salt, a montanic acid wax, a polyethylene wax, and a fluorine wax. Fibers for artificial hair, which are more than seeds, are provided.

As a result of diligent studies to solve the above problems, the present inventors have found that the artificial hair fiber having the above composition is excellent in productivity and flame retardancy, and that color unevenness is suppressed. It has been completed.

Hereinafter, embodiments of the present invention will be described.
The artificial hair fiber of the present embodiment contains 5 to 40 parts by mass of a bromine-based flame retardant and 0.1 to 10 parts by mass of a processed pigment with respect to 100 parts by mass of polyamide, and the processed pigment is a colorant and a dispersant. When the total of the colorant and the dispersant is 100% by mass, the dispersant is 20 to 80% by mass, and the dispersant is a montanic acid metal salt, a montanic acid-based wax, a polyethylene-based wax, and the like. One or more of fluorowax. The artificial hair fiber can be produced by melt-spinning a resin composition having such a composition.
Hereinafter, each component will be described in detail.

<Polyamide>
The polyamide preferably contains an aliphatic polyamide, may be composed of only an aliphatic polyamide, or may contain an aliphatic polyamide and a semi-aromatic polyamide.

The aliphatic polyamide is a polyamide having no aromatic ring, and is synthesized as the aliphatic polyamide by the copolymerization reaction of n-nylon formed by the ring-opening polymerization of lactam and the aliphatic diamine and the aliphatic dicarboxylic acid. N, m-nylon can be mentioned. Examples of the aliphatic polyamide include polyamide 6 and polyamide 66. Polyamide 66 is preferable from the viewpoint of heat resistance.

The semi-aromatic polyamide has a skeleton obtained by condensation polymerizing an aliphatic diamine and an aromatic dicarboxylic acid. Examples of the semi-aromatic polyamide include polyamide 6T, polyamide 9T, polyamide 10T, and modified polyamide 6T, modified polyamide 9T, and modified polyamide 10T obtained by copolymerizing a modifying monomer based on them.

The weight average molecular weight (Mw) of the polyamide is, for example, 65,000 to 150,000. When the Mw is 65,000 or more, the drip resistance is particularly good, while when the Mw exceeds 150,000, the melt viscosity of the material increases and the processability at the time of fiberization is inferior. 10,000 or less is preferable. Considering the balance between drip resistance and processability, Mw is more preferably 70,000 to 120,000.

<Brominated flame retardant>
The amount of the brominated flame retardant added is 5 to 40 parts by mass, preferably 10 to 30 parts by mass with respect to 100 parts by mass of the polyamide. This is because the balance between the effect of imparting drip resistance and the workability is good in the above range.

Examples of the bromine-based flame retardant include brominated phenol condensate, brominated polystyrene resin, brominated benzyl acrylate-based flame retardant, brominated epoxy resin, brominated phenoxy resin, brominated polycarbonate resin and bromine-containing triazine-based compound. .. Considering the balance between drip resistance, processability, transparency (clarity) of the raw yarn, etc., a brominated epoxy resin or a brominated phenoxy resin containing the structural formula shown in (1) below is preferable.

<Processed pigment>
Processing pigments include colorants and dispersants. It can be manufactured by mixing a colorant and a dispersant. The amount of the processing pigment added is 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, and more preferably 0.2 to 2 parts by mass with respect to 100 parts by mass of the polyamide. In the above range, the balance between colorability and processability is good.

The colorant is a pigment, a dye, or the like, and by containing the colorant, pre-colored fibers (so-called dyed fibers) can be obtained.

Examples of the colorant include a black colorant, a red colorant, a yellow colorant, a purple colorant and the like, and one or more of these are used.

Examples of the black colorant include Pigment Black 7, Solvent Black 7, and the like, and Pigment Black 7 is preferable from the viewpoint of flame retardancy.

Examples of the red colorant include Pigment Red 149, Pigment Red 177, Solvent Red 179 and the like, and Pigment Red 149 is preferable from the viewpoint of flame retardancy.

Examples of the yellow colorant include Pigment Yellow 147, Solvent Yellow 163, Solvent Yellow 21, Pigment Yellow 184 and the like, and Pigment Yellow 147 or Solvent Yellow 163 is preferable from the viewpoint of flame retardancy.

Examples of the purple colorant include Pigment Violet 19, Pigment Violet 29 and the like, and Pigment Violet 19 is preferable from the viewpoint of flame retardancy.

The dispersant has a function of enhancing the dispersibility of the colorant in the polyamide. The dispersant is one or more of a montanic acid metal salt, a montanic acid-based wax, a polyethylene-based wax, and a fluorine wax. Preferred is a metal salt of montanic acid. This is because the yarn breakage resistance becomes particularly good in this case. Examples of the metal salt of montanic acid include calcium montanate, zinc montanate, sodium montanate and the like. The dispersant is particularly preferably calcium montanate. This is because the occurrence of color unevenness is particularly suppressed in this case.

Assuming that the total of the colorant and the dispersant is 100% by mass, the dispersant is 20 to 80% by mass, preferably 30 to 70% by mass. If the amount of the dispersant is too small, the long-run property is deteriorated, and if the amount of the dispersant is too large, the yarn breakage resistance is deteriorated.

<Other additives>
Additives such as flame retardant aids, organic fine particles, heat resistant agents, light stabilizers, fluorescent agents, antioxidants, antistatic agents, and plasticizers may be added to the resin composition constituting the artificial hair fiber, if necessary. Agents, lubricants and the like can be contained.

<Manufacturing process>
An example of the manufacturing process of the artificial hair fiber will be described below.
The method for producing an artificial hair fiber according to an embodiment of the present invention includes a melt spinning step, a drawing step, and a heat treatment step.
Hereinafter, each step will be described in detail.

(Melting spinning process)
In the melt spinning step, undrawn yarn is produced by melt spinning the resin composition. Specifically, first, the above-mentioned resin composition is melt-kneaded. As an apparatus for melt-kneading, various general kneading machines can be used. Examples of the kneader include a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, and a kneader. Of these, a twin-screw extruder is preferable from the viewpoint of adjusting the degree of kneading and easiness of operation. Fibers for artificial hair can be produced by melt spinning by a normal melt spinning method under appropriate temperature conditions depending on the type of polyamide.

The temperature of the melt spinning device such as the extruder, the mouthpiece, and the gear pump, if necessary, is set to, for example, 270 to 310 ° C., and the melt spinning is performed. Is adjusted to obtain an undrawn yarn. The temperature of the melt spinning apparatus can be appropriately adjusted according to the composition of the resin composition. Further, regardless of cooling by a water tank, spinning by cooling with cold air is also possible. The temperature of the cooling water tank, the temperature of the cold air, the cooling time, and the take-up speed can be appropriately adjusted according to the discharge amount and the number of holes in the mouthpiece.

The single fiber degree of the artificial hair fiber in the present embodiment is preferably 20 to 100 decitex, more preferably 35 to 80 decitex. In order to obtain this single fineness, it is preferable to set the fineness of the fiber (undrawn yarn) immediately after the melt spinning step to 300 decitex or less. If the fineness of the undrawn yarn is small, the draw ratio may be small in order to obtain fibers for artificial hair with fine fineness, and the fibers for artificial hair after the drawing treatment are less likely to be glossy. This is because it tends to be easier to maintain a glossy state.

The cross-sectional area of the nozzle used for melt spinning is not particularly limited, but may be 0.1 to 2 mm. Further, in consideration of quality such as curl characteristics for artificial hair, it is preferable to melt and flow out from a nozzle ^{having a cross-sectional area of one nozzle hole of 0.5 mm 2 or less.} When the cross-sectional area of one nozzle hole ^{is smaller than 0.5 mm 2} , the tension for forming an undrawn yarn or a heated yarn with fine fineness is suppressed to a low level, residual strain is reduced, curl retention, etc. This is because the quality is less likely to deteriorate.

At the time of melt spinning, the nozzle pressure is preferably 50 MPa or less. This is because the load applied to the thrust portion of the extruder tends to be low, and the extruder tends to be less likely to malfunction, and resin leakage tends to be less likely to occur from the connection portion of the turn head, die, or the like.

As the mold used for melt spinning, one or more nozzle-shaped spinning dies selected from the group consisting of circular, cocoon-shaped, Y-shaped, H-shaped, and X-shaped may be used. Since these molds do not have a complicated shape, it is easy to produce fibers according to the mold. In addition, the fibers produced using these molds are easy to maintain their shape and are relatively easy to process.

(Stretching process)
In the drawing step, the obtained undrawn yarn is drawn by 150 to 500% to produce a drawn yarn. By such drawing, drawn yarn having a fineness of 100 decitex or less can be obtained, and the tensile strength of the fiber can be improved. The drawing treatment includes a two-step method in which the undrawn yarn is once wound on a bobbin and then drawn in a step different from the melt spinning step, or direct spinning drawing in which the undrawn yarn is continuously drawn from the melt spinning step without being wound on the bobbin. Any method of the method may be used. Further, the stretching treatment is carried out by a one-step stretching method in which the drawing is stretched to a desired stretching ratio at one time, or a multi-step stretching method in which the stretching is carried out to a desired stretching ratio by stretching two or more times. As the heating means in the case of performing 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 also be used in combination as appropriate. The draw ratio is preferably 200 to 400%. This is because when the draw ratio is moderately large, the strength of the fiber tends to be developed easily, and when the draw ratio is moderately 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 ° C. This is because if the stretching treatment temperature is too low, the strength of the fibers tends to be low and yarn breakage tends to occur, and if the stretching treatment temperature is too high, the tactile sensation of the obtained fibers tends to be a plastic-like slippery feel.

(Heat treatment process)
In the heat treatment step, the drawn yarn is heat-treated at a heat treatment temperature of 155 ° C. or higher. By this heat treatment, the heat shrinkage rate of the drawn yarn can be reduced. The heat treatment may be carried out continuously after the stretching treatment, or may be carried out with a time after being wound once. The heat treatment temperature is preferably 160 ° C. or higher, more preferably 170 ° C. or higher, still more preferably 180 ° C. or higher. The upper limit of the heat treatment temperature is not particularly specified, but is, for example, 220 ° C.

Examples of the artificial hair fiber according to the present invention will be described in detail with reference to a comparative example using a table. Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Polyamides, flame retardants, and processed pigments dried so that the hygroscopicity was less than 1000 ppm were blended so as to have the compounding ratios shown in Examples and Comparative Examples of Tables 1 to 4. The blended material was kneaded using a φ30 mm twin-screw extruder to obtain raw material pellets for spinning.

Then, after dehumidifying and drying the pellets so that the water absorption rate becomes 1000 ppm or less, spinning is performed using a φ40 mm single-screw spinning machine, and the molten resin discharged from the die having a hole diameter of 0.5 mm / piece is discharged at about 30 ° C. While cooling through a water tank, the discharge amount and the winding speed were adjusted to prepare an undrawn yarn having a set fineness. The melt spinning machine is provided with a screw, a wire mesh filter, and a die in this order, and the pellet is heated and melted by the screw to form a molten resin composition, and the molten resin composition is filtered from the filter and then placed from the die. It is configured to. The set temperature of the dice was 290 ° C.

The obtained undrawn yarn was stretched at 100 ° C. and then annealed at 150 ° C. to 200 ° C. to obtain fibers for artificial hair having a predetermined strength. The stretching ratio was 3 times, and the relaxation rate at the time of annealing was 0.5 to 3%. The relaxation rate at the time of annealing is a value calculated by (rotational speed of the take-up roller at the time of annealing) / (rotational speed of the feeding roller at the time of annealing).

The obtained artificial hair fibers were evaluated for color unevenness, transparency (clarity), flame retardancy, yarn breakage resistance, and long-run property according to the evaluation methods and criteria described later. The results are shown in Tables 1 to 4.

The following materials were adopted as the materials shown in Tables 1 to 4.
Polyamide 66 (weight average molecular weight 90000): Zytel 42A manufactured by DuPont
Polyamide 6 (weight average molecular weight 90000): in-house brominated epoxy: Sakamoto Yakuhin Kogyo Co., Ltd., SRT-20000
Calcium montanate: Zinc montanate manufactured by Nitto Kasei Kogyo Co., Ltd .: Sodium montanate manufactured by Nitto Kasei Kogyo Co., Ltd .: Montanic acid ester wax manufactured by Nitto Kasei Kogyo Co., Ltd.
Polyethylene wax: Clariant Japan Co., Ltd., LicowaxPE520
Montanic acid wax / fluorine wax blend product: Clariant Japan Co., Ltd., WaxComposite G431L
Calcium stearate: manufactured by Nitto Kasei Kogyo Co., Ltd. 12-Hydroxy calcium stearate: manufactured by Nitto Kasei Kogyo Co., Ltd.
Pigment Black 7: Made in-house
Solvent Black 7: Made by Orient Chemical Industry Co., Ltd.
Pigment Red 149: Made by Clariant Japan
Pigment Red 177: Made by BASF
Solvent Red 179: Made by Orient Chemical Industry Co., Ltd.
Pigment Yellow 147: Made by BASF
Solvent Yellow 163: Made by BASF
Solvent Yellow 21: Made by Orient Chemical Industry Co., Ltd.
Pigment Yellow 184: Made by BASF
Pigment Violet 19: Made by BASF
Pigment Violet 29: Made by BASF

The evaluation methods and criteria for each evaluation item in Tables 1 to 4 are as follows.

<Color unevenness>
Color unevenness is evaluated by bundling the fibers for artificial hair of Examples and Comparative Examples into a length of 200 mm and a weight of 1.0 g, and visually evaluating them by a fiber treatment engineer for artificial hair (with 5 years or more of practical experience) according to the following evaluation criteria. did.
○: No color unevenness △: Slight color unevenness is seen, but there is no problem in using it as an artificial hair fiber ×: At first glance, there is clearly color unevenness, and it can withstand use as an artificial hair fiber. No

<Transparency (clarity)>
For transparency (clarity), the fibers for artificial hair of Examples and Comparative Examples are bundled into a length of 200 mm and a weight of 1.0 g, and a fiber treatment engineer for artificial hair (more than 5 years of work experience) visually determines that the hair is human. A comparative evaluation was performed and evaluated according to the following evaluation criteria.
◯: Has transparency (clarity) similar to human hair Δ: Differences are observed when compared with human hair, but has transparency (clearness) that is generally close to human hair ×: Clearly cloudy at first glance And there is a difference from human hair

<Flame retardant>
For flame retardancy, a fiber bundle sample was used in which artificial hair fibers were cut to a length of 30 cm and separated into a number of 2 g, and one end of the fiber bundle was fixed and hung vertically. A flame having a length of 20 mm was brought into contact with the lower end for 5 seconds, and then the fire spread time after the release was measured, and the following determination was made. As the result, the average value of the result measured three times was used.
◯: Fire spread time is less than 5 seconds Δ: Fire spread time is 5 seconds or more and less than 10 seconds ×: Fire spread time is 10 seconds or more

<Thread breakage resistance>
The yarn breakability was evaluated as follows by visually observing the occurrence of yarn breakage while the undrawn yarn was formed by melt spinning.
◯: Thread breakage is 1 time or less / 1 hour Δ: Thread breakage is 2 to 3 times / 1 hour ×: Thread breakage is 4 times or more / 1 hour

<Long run property>
The long-run property was evaluated by the time during which continuous spinning was possible without changing the filter.
◯: 48 hours or more Δ: 24-48 hours ×: less than 24 hours

<Discussion>
In all the examples, evaluation results of ◯ or Δ were obtained in all of color unevenness, transparency (clarity), flame retardancy, yarn breakage resistance, and long-running property.
On the other hand, in all the comparative examples, the evaluation was x in at least one evaluation item. In particular, in Comparative Examples 1 to 2, 5 to 6, 9 to 10 and 13 to 14 in which the dispersant was not a metal salt of montanic acid, the yarn breakage resistance was not good. Further, in Comparative Examples 3, 7, 11 and 15 in which the ratio of the dispersant was too small, the long-run property was not good. In Comparative Examples 4, 8, 12, and 16 in which the proportion of the dispersant was too large, the yarn breakage resistance was not good.

In the examples, when the metal salt of montanic acid was used as the dispersant, the yarn breakage resistance was particularly good as compared with the case where other substances were used. In addition, when calcium montanate was used, the color unevenness was particularly small as compared with the case where other substances were used.

Furthermore, the black colorant had good flame retardancy when Pigment Black 7 was used. The red colorant had good flame retardancy when Pigment Red 149 was used. As for the yellow colorant, flame retardancy was good when Pigment Yellow 147 or Solvent Yellow 163 was used. The purple colorant had good flame retardancy when Pigment Violet 19 was used.

Claims (4)

It contains 5 to 40 parts by mass of a brominated flame retardant and 0.01 to 10 parts by mass of a processing pigment with respect to 100 parts by mass of polyamide.
The processed pigment contains a colorant and a dispersant, and the processing pigment contains a colorant and a dispersant.
Assuming that the total of the colorant and the dispersant is 100% by mass, the dispersant is 20 to 80% by mass.
The dispersant is one or more of a montanic acid metal salt, a montanic acid-based wax, a polyethylene-based wax, and a fluorine wax, and is a fiber for artificial hair. The artificial hair fiber according to claim 1.
The dispersant is a fiber for artificial hair containing a metal salt of montanic acid. The artificial hair fiber according to claim 2.
The metal salt of montanic acid is a fiber for artificial hair, which is calcium montanate. The artificial hair fiber according to any one of claims 1 to 3.
The colorant is a fiber for artificial hair, which is at least one selected from Pigment Black 7, Pigment Red 149, Pigment Yellow 147, Solvent Yellow 163 and Pigment Violet 19.