JP7344273B2 - Fiber for artificial hair - Google Patents

Description

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

Patent Document 1 discloses an artificial hair fiber made from a resin composition containing polyamide and a brominated flame retardant.

JP2011-246844A

By the way, coloring agents such as black or red are sometimes added to artificial hair fibers for coloring, but the dispersibility of the coloring agent in polyamide may not be sufficient, and in that case, extrusion When a resin composition is made into fibers using a machine, thread breakage and filter clogging of the extruder frequently occur, which may reduce productivity.

The present invention has been made in view of these circumstances, and provides an artificial hair fiber that is excellent in productivity and flame retardancy, and has suppressed color unevenness.

According to the present invention, 5 to 40 parts by mass of a brominated flame retardant and 0.01 to 10 parts by mass of a processed pigment are contained based on 100 parts by mass of polyamide, and the processed pigment contains a coloring agent and a dispersant, and the processed pigment contains a colorant and a dispersant; When the total of the colorant and the dispersant is 100% by mass, the dispersant accounts for 20 to 80% by mass, and the dispersant includes one of montanic acid metal salt, montanic acid wax, polyethylene wax, and fluorine wax. Provided are fibers for artificial hair that are more than 100% of species.

The present inventors conducted intensive studies to solve the above problems, and found that the artificial hair fiber having the above composition has excellent productivity and flame retardancy, and suppresses color unevenness. It has reached completion.

Embodiments of the present invention will be described below.
The artificial hair fiber of this embodiment contains 5 to 40 parts by mass of a brominated flame retardant and 0.1 to 10 parts by mass of a processed pigment based on 100 parts by mass of polyamide, and the processed pigment contains a colorant and a dispersant. If the total of the colorant and the dispersant is 100% by mass, the dispersant accounts for 20 to 80% by mass, and the dispersant includes a montanic acid metal salt, a montanic acid wax, a polyethylene wax, One or more types of fluorine wax. Fibers for artificial hair can be produced by melt-spinning a resin composition having such a composition.
Each component will be explained in detail below.

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

Aliphatic polyamides are polyamides that do not have aromatic rings, and include n-nylon, which is formed by ring-opening polymerization of lactam, and synthesized by cocondensation polymerization of aliphatic diamines and aliphatic dicarboxylic acids. Examples include n,m-nylon. Examples of aliphatic polyamides include polyamide 6 and polyamide 66. Polyamide 66 is preferred from the viewpoint of heat resistance.

Semi-aromatic polyamide has a skeleton obtained by condensation polymerization of aliphatic diamine and 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, which are obtained by copolymerizing a modifying monomer based on these polyamides.

The weight average molecular weight (Mw) of the polyamide is, for example, 65,000 to 150,000. When Mw is 65,000 or more, drip resistance becomes particularly good, but when Mw exceeds 150,000, the melt viscosity of the material increases and the processability when forming into fibers is poor. It is preferably 10,000 or less. Considering the balance between drip resistance and processability, the 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 weight, preferably 10 to 30 parts by weight, per 100 parts by weight of the polyamide. This is because within the above range, there is a good balance between the effect of imparting drip resistance and workability.

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

<Processed pigment>
Processed pigments include colorants and dispersants. It can be manufactured by mixing a colorant and a dispersant. The amount of processed pigment added is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and more preferably 0.2 to 2 parts by weight, based on 100 parts by weight of the polyamide. Within the above range, there is a good balance between colorability and processability.

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

Examples of the coloring agent include black coloring agents, red coloring agents, yellow coloring agents, purple coloring agents, and the like, and one or more of these may be used.

Examples of the black colorant include Pigment Black 7, Solvent Black 7, etc., 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, etc., and Pigment Red 149 is preferred from the viewpoint of flame retardancy.

Examples of the yellow colorant include Pigment Yellow 147, Solvent Yellow 163, Solvent Yellow 21, and Pigment Yellow 184, with Pigment Yellow 147 and Solvent Yellow 163 being preferred from the viewpoint of flame retardancy.

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

The dispersant has the function of increasing the dispersibility of the colorant in the polyamide. The dispersant is one or more of montanic acid metal salts, montanic acid waxes, polyethylene waxes, and fluorine waxes. Preferred are metal montanate salts. This is because in this case, yarn breakage resistance becomes particularly good. Examples of the montanate metal salt include calcium montanate, zinc montanate, sodium montanate, and the like. It is particularly preferred that the dispersant is calcium montanate. This is because in this case, the occurrence of color unevenness is particularly suppressed.

When the total of the colorant and the dispersant is 100% by mass, the dispersant accounts for 20 to 80% by mass, preferably 30 to 70% by mass. If the amount of dispersant is too small, long-run properties will deteriorate, and if the amount of dispersant is too large, thread breakage resistance will deteriorate.

<Other additives>
The resin composition constituting the fiber for artificial hair may contain additives as necessary, such as flame retardant aids, organic fine particles, heat resistant agents, light stabilizers, fluorescent agents, antioxidants, antistatic agents, and plasticizers. It is possible to contain agents, lubricants, etc.

<Manufacturing process>
Below, an example of the manufacturing process of the fiber for artificial hair will be explained.
A method for producing an artificial hair fiber according to an embodiment of the present invention includes a melt spinning process, a stretching process, and a heat treatment process.
Each step will be explained in detail below.

(melt spinning process)
In the melt spinning step, undrawn yarn is produced by melt spinning the resin composition. Specifically, first, the resin composition described above is melt-kneaded. As a device for melt-kneading, various general kneading machines can be used. Examples of the kneading machine include a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, and a kneader. Among these, a twin-screw extruder is preferred in terms of adjustment of the degree of kneading and ease of operation. Fibers for artificial hair can be produced by melt spinning using a normal melt spinning method under appropriate temperature conditions depending on the type of polyamide.

Melt spinning is performed by setting the temperature of the extruder, spinneret, gear pump, etc. to 270 to 310°C, for example, and cooling it in a water tank containing water for cooling.While controlling the fineness, the take-up speed is adjusted. An undrawn yarn can be obtained by adjusting the The temperature of the melt spinning device can be adjusted as appropriate depending on the composition of the resin composition. Moreover, spinning by cooling with cold air is also possible, regardless of cooling with a water tank. The temperature of the cooling water tank, the temperature of the cold air, the cooling time, and the take-up speed can be adjusted as appropriate depending on the discharge amount and the number of holes in the mouthpiece.

The single fineness of the artificial hair fiber in this embodiment is preferably 20 to 100 dtex, more preferably 35 to 80 dtex. In order to obtain this single fineness, it is preferable that the fineness of the fiber (undrawn yarn) immediately after the melt spinning process is 300 decitex or less. If the fineness of the undrawn yarn is small, the drawing ratio may be small in order to obtain fine-grained artificial hair fibers, and the artificial hair fibers after the drawing process will be less likely to have gloss, resulting in semi-gloss to 7 part gloss. 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. Furthermore, in consideration of quality aspects such as curling 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. If the cross-sectional area of one nozzle hole is smaller than 0.5 ^mm2 , the tension required to make fine-grained undrawn yarn or hot-rolled yarn can be kept low, residual strain can be reduced, and curl retention can be improved. This is because quality is less likely to deteriorate.

During melt spinning, the nozzle pressure is preferably 50 MPa or less. This is because the load applied to the thrust part of the extruder is reduced, making it less likely that the extruder will malfunction, and that resin leakage from the connection parts of the turn head, die, etc. will be less likely to occur.

The mold used for melt spinning may be a spinning mold with one or more nozzle shapes selected from the group consisting of circular, cocoon-shaped, Y-shaped, H-shaped, and X-shaped. Since these molds do not have complicated shapes, it is easy to produce fibers that match the mold. In addition, fibers made using these molds tend to retain 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, a drawn yarn having a fineness of 100 decitex or less can be obtained, and the tensile strength of the fiber can be improved. Stretching treatment includes two-step methods in which the undrawn yarn is wound on a bobbin and then stretched in a process separate from the melt-spinning process, and direct spinning and drawing in which the undrawn yarn is drawn continuously from the melt-spinning process without being wound on a bobbin. Any method of law may be used. Further, the stretching process is carried out by a one-stage stretching method in which the film is stretched to a target stretching ratio in one step, or a multi-stage stretching method in which the film is stretched to a target stretching ratio in two or more times. As a heating means in the case of hot stretching treatment, a heating roller, a heat plate, a steam jet device, a hot water tank, etc. can be used, and these can also be used in combination as appropriate. The stretching ratio is preferably 200 to 400%. This is because when the stretching ratio is appropriately large, the strength of the fiber tends to be developed more easily, and when the stretching ratio is appropriately small, thread breakage tends to be less likely to occur during the drawing process.

The temperature during the stretching treatment is preferably 90 to 120°C. This is because if the stretching temperature is too low, the strength of the fibers will be low and fiber breakage will tend to occur easily, whereas if the stretching temperature is too high, the texture of the resulting fibers will tend to be plastic-like and slippery.

(Heat treatment process)
In the heat treatment step, the drawn yarn is heat treated at a heat treatment temperature of 155° C. or higher. This heat treatment can reduce the thermal shrinkage rate of the drawn yarn. The heat treatment can be performed continuously after the stretching treatment, or can be performed at intervals after the film is once wound up. The heat treatment temperature is preferably 160°C or higher, more preferably 170°C or higher, and even more preferably 180°C or higher. Although the upper limit of the heat treatment temperature is not particularly specified, it is, for example, 220°C.

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

Polyamide, flame retardant, and processed pigment that had been dried so that the moisture absorption rate was less than 1000 ppm were blended at the blending ratios shown in Examples and Comparative Examples in Tables 1 to 4. The blended materials were kneaded using a φ30 mm twin screw extruder to obtain raw material pellets for spinning.

Next, the pellets were dehumidified and dried so that the water absorption rate was 1000 ppm or less, and then spun using a φ40 mm uniaxial melt spinning machine. While cooling through a water bath, the discharge amount and winding speed were adjusted to create an undrawn yarn with a set fineness. The melt spinning machine is equipped with a screw, a wire mesh filter, and a die in this order, and the pellets are heated and melted by the screw to become a molten resin composition, and after this molten resin composition is filtered by a filter, it is placed from the die. It is configured to The set temperature of the dice was 290°C.

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

The obtained artificial hair fibers were evaluated for color unevenness, transparency (clarity), flame retardance, thread breakage resistance, and long run performance according to the evaluation method and criteria described below. The results are shown in Tables 1 to 4.

The following materials were used in Tables 1 to 4.
Polyamide 66 (weight average molecular weight 90000): DuPont, Zytel 42A
Polyamide 6 (weight average molecular weight 90000): In-house brominated epoxy: SRT-20000, manufactured by Sakamoto Pharmaceutical Co., Ltd.
Calcium montanate: Nitto Kasei Kogyo Co., Ltd. Zinc montanate: Nitto Kasei Kogyo Co., Ltd. Sodium montanate: Nitto Kasei Kogyo Co., Ltd. Montanic acid ester wax: Clariant Japan Co., Ltd., LicowaxE
Polyethylene wax: manufactured by Clariant Japan Co., Ltd., Licowax PE520
Montanic acid wax/fluorine wax blend product: WaxComposite G431L, manufactured by Clariant Japan Co., Ltd.
Calcium stearate: Nitto Kasei Kogyo Co., Ltd. Calcium 12-hydroxystearate: Nitto Kasei Kogyo Co., Ltd.
Pigment Black 7: Made in-house
Solvent Black 7: Manufactured by Orient Chemical Industry Co., Ltd.
Pigment Red 149: Manufactured by Clariant Japan
Pigment Red 177: Manufactured by BASF
Solvent Red 179: Manufactured by Orient Chemical Industry Co., Ltd.
Pigment Yellow 147: Manufactured by BASF
Solvent Yellow 163: Manufactured by BASF
Solvent Yellow 21: Manufactured by Orient Chemical Industry Co., Ltd.
Pigment Yellow 184: Manufactured by BASF
Pigment Violet 19: Manufactured by BASF
Pigment Violet 29: Manufactured by BASF

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

<Uneven color>
Color unevenness was evaluated using the following evaluation criteria by bundling the artificial hair fibers of Examples and Comparative Examples to a length of 200 mm and weight of 1.0 g, and visually inspecting them by an artificial hair fiber processing engineer (with 5 years or more of work experience). did.
○: No color unevenness △: Slight color unevenness is seen, but there is no problem in using it as an artificial hair fiber ×: There is obvious color unevenness at first glance, but it can withstand use as an artificial hair fiber do not have

<Transparency (clarity)>
Transparency (clarity) was determined by bundling the artificial hair fibers of Examples and Comparative Examples to a length of 200 mm and a weight of 1.0 g, and visually inspecting them by an artificial hair fiber processing engineer (with 5 or more years of work experience) to determine whether they were human hair or not. Comparative evaluation was conducted and evaluated using the following evaluation criteria.
○: Transparency (clarity) similar to human hair △: Differences are observed when compared with human hair, but transparency (clarity) is generally similar to human hair ×: Obviously cloudy at first glance The difference between human hair and human hair is recognized.

<Flame retardancy>
Flame retardancy was tested by cutting artificial hair fibers into 30cm lengths, dividing them into 2g fiber bundle samples, fixing one end of this fiber bundle and hanging it vertically. A flame with a length of 20 mm was brought into contact with the lower end for 5 seconds, and the flame spread time after the flame was removed was measured and the following judgments were made. For the results, the average value of three measurements was used.
○: Fire spread time is less than 5 seconds △: 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 breakage property was evaluated as follows by visually observing the occurrence of yarn breakage during melt spinning and producing an undrawn yarn.
○: Thread breakage occurs once or less/1 hour △: Thread breakage occurs 2 to 3 times/1 hour ×: Thread breakage occurs 4 or more times/1 hour

<Long run performance>
Long-run performance was evaluated based on the time during which spinning could be continued without changing the filter.
○: 48 hours or more △: 24 to 48 hours ×: less than 24 hours

<Consideration>
In all Examples, evaluation results of ◯ or △ were obtained in all of color unevenness, transparency (clarity), flame retardancy, thread breakage resistance, and long run property.
On the other hand, all comparative examples were evaluated as × in at least one evaluation item. In particular, Comparative Examples 1 to 2, 5 to 6, 9 to 10, and 13 to 14, in which the dispersant was not a montanic acid metal salt, had poor thread breakage resistance. Furthermore, in Comparative Examples 3, 7, 11, and 15, in which the proportion of the dispersant was too small, the long run properties were 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 a metal montanate salt was used as a dispersant, yarn breakage resistance was particularly good compared to when other substances were used. Furthermore, when calcium montanate was used, color unevenness was particularly small compared to when other substances were used.

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

Claims (4)

Contains 5 to 40 parts by mass of a brominated flame retardant and 0.01 to 10 parts by mass of a processed pigment based on 100 parts by mass of polyamide,
The processed pigment includes 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,
The fiber for artificial hair, wherein the dispersant is one or more of a montanic acid metal salt, a montanic acid wax, a polyethylene wax, and a fluorine wax. The artificial hair fiber according to claim 1,
The dispersing agent is an artificial hair fiber containing a montanic acid metal salt. The artificial hair fiber according to claim 2,
The montanic acid metal salt is calcium montanate, an artificial hair fiber. The artificial hair fiber according to any one of claims 1 to 3,
An artificial hair fiber, wherein the colorant is at least one selected from Pigment Black 7, Pigment Red 149, Pigment Yellow 147, Solvent Yellow 163, and Pigment Violet 19.