US20240368830A1

US20240368830A1 - Antibacterial polyacrylonitrile-based synthetic fiber, method for producing same, and headdress product

Info

Publication number: US20240368830A1
Application number: US18/778,255
Authority: US
Inventors: Takaaki Kobashi; Akihiro Okamoto; Takeshi Tanaka
Original assignee: Kaneka Corp
Current assignee: Kaneka Corp
Priority date: 2022-03-30
Filing date: 2024-07-19
Publication date: 2024-11-07
Also published as: KR20240128093A; WO2023190761A1; JPWO2023190761A1

Abstract

An antibacterial polyacrylonitrile-based synthetic fiber suitable for synthetic hair that is superior in an antibacterial property and texture, a method for producing the fiber, and a headdress product containing the fiber are provided. The antibacterial polyacrylonitrile-based synthetic fiber contains a quaternary ammonium salt (B) represented by formula (1):

and a non-ionic surfactant (C), that are attached to a polyacrylonitrile-based synthetic fiber (A). The non-ionic surfactant (C) contains a sorbitan fatty acid ester (C1) and polyoxyethylene triglyceride (C2). The amount of the quaternary ammonium salt (B) attached is between 0.05 mass % and 0.3 mass % both inclusive with respect to a total mass of the antibacterial polyacrylonitrile-based synthetic fiber. The amount of the non-ionic surfactant (C) attached is between 0.15 mass % and 0.9 mass % both inclusive with respect to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber.

Description

TECHNICAL FIELD

One or more embodiments of the present invention relate to an antibacterial polyacrylonitrile-based synthetic fiber, a method for producing the same and a headdress product.

BACKGROUND

It has been sought to impart various functions to polyacrylonitrile-based synthetic fibers. Patent document 1, for example, indicates that application of a quaternary ammonium salt and a specific non-ionic surfactant to a polyacrylonitrile-based synthetic fiber improves antibacterial activity of the polyacrylonitrile-based synthetic fiber.

PATENT DOCUMENT

Patent Document 1: Japanese Unexamined Patent Application, Publication No. H8-325940
However, the polyacrylonitrile-based synthetic fiber comprising the surfactant disclosed in Patent Document 1 as an antibacterial agent has poor tactile sensation despite of excellent antibacterial activity. Although polyacrylonitrile-based synthetic fibers are widely used for artificial hair, polyacrylonitrile-based synthetic fibers with poor tactile sensation do not fulfill demand characteristics of artificial hair.
With the foregoing in view, one or more embodiments of the present invention provide an antibacterial polyacrylonitrile-based synthetic fiber that has excellent antibacterial activity and excellent tactile sensation and is suitable for artificial hair, a method for producing the fiber and a headdress product including the fiber.

SUMMARY

The inventors of one or more embodiments of the present invention extensively studied amounts of a quaternary ammonium salt (B) and a specific non-ionic surfactant (C) adhered to a polyacrylonitrile-based synthetic fiber (A) and found that the above can be addressed, thereby achieving one or more embodiments of the present invention.
One or more embodiments of the present invention relate to the antibacterial polyacrylonitrile-based synthetic fiber, the method for producing the fiber and the headdress product including the fiber indicated below.
[1] An antibacterial polyacrylonitrile-based synthetic fiber, including a quaternary ammonium salt (B) represented by following formula (1):
wherein in formula (1), R¹is an alkyl group with 8-18 carbon atoms; R²to R⁴are each independently a methyl group, an alkyl group with 8-18 carbon atoms, a 3-(trihydroxysilyl) propyl group, a 3-(trimethoxysilyl) propyl group or a benzyl group; n is 1 or 2; and Xⁿ⁻is an inorganic acid ion selected from the group consisting of bromide ions, chloride ions, fluoride ions, hydroxide ions, carbonate ions, sulfate ions, nitrate ions, phosphate ions and borate ions or a monoalkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms or a dialkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms;

- and
- a non-ionic surfactant (C)
- adhered to a polyacrylonitrile-based synthetic fiber (A), wherein
- the non-ionic surfactant (C) contains a sorbitan fatty acid ester (C1) and a polyoxyethylene triglyceride (C2),
- the amount of the quaternary ammonium salt (B) adhered is 0.05% by mass or more and 0.3% by mass or less relative to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber, and
- the amount of the non-ionic surfactant (C) adhered is 0.15% by mass or more and 0.9% by mass or less relative to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber.

[2] The antibacterial polyacrylonitrile-based synthetic fiber according to [1], wherein R¹is an alkyl group with 8-18 carbon atoms and R²to R⁴are each a methyl group, or R¹and R²are each an alkyl group with 8-18 carbon atoms and R³and R⁴are each a methyl group, or R¹is an alkyl group with 8-18 carbon atoms, R²is a 3-(trihydroxysilyl) propyl group and R³and R⁴are each a methyl group, or R¹is an alkyl group with 8-18 carbon atoms, R²is a 3-(trimethoxysilyl) propyl group and R³and R⁴are each a methyl group; n is 1; and Xⁿ⁻is a chloride ion or a dialkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms.
[3] The antibacterial polyacrylonitrile-based synthetic fiber according to [1] or [2], wherein the content of the sorbitan fatty acid ester (C1) is 20% by mass or more and 90% by mass or less relative to the total mass of the non-ionic surfactant (C).
[4] The antibacterial polyacrylonitrile-based synthetic fiber according to any one of [1] to [3], having a filament fineness of 1 dtex or more and 100 dtex or less.
[5] The antibacterial polyacrylonitrile-based synthetic fiber according to any one of [1] to [4] for use for artificial hair.
[6] A headdress product, including the antibacterial polyacrylonitrile-based synthetic fiber according to any one of [1] to [5].
[7] The headdress product according to [6], in which the headdress product is one product selected from the group consisting of hair wigs, toupees, weavings, hair extensions, hair braids, hair accessories and doll hair.
[8] A method for producing the antibacterial polyacrylonitrile-based synthetic fiber according to any one of [1] to [5], including

- wet-spinning a spinning solution containing an acrylonitrile polymer to obtain a coagulated yarn and bringing a yarn to be treated before drying into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C).

[9] A method for producing the antibacterial polyacrylonitrile-based synthetic fiber according to any one of [1] to [5], including

- bringing a dried polyacrylonitrile-based synthetic fiber (A) into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C) and drying a yarn after the contact treatment.

One or more embodiments of the present invention can provide an antibacterial polyacrylonitrile-based synthetic fiber that has excellent antibacterial activity and excellent tactile sensation and is suitable for artificial hair, a method for producing the fiber and a headdress product including the fiber.

DETAILED DESCRIPTION

Antibacterial Polyacrylonitrile-Based Synthetic Fiber

The antibacterial polyacrylonitrile-based synthetic fiber includes a quaternary ammonium salt (B) described hereinbelow and a non-ionic surfactant (C) described hereinbelow adhered to a polyacrylonitrile-based synthetic fiber (A). More specifically, in the antibacterial polyacrylonitrile-based synthetic fiber, the quaternary ammonium salt (B) and the non-ionic surfactant (C) are adhered to the surface of the polyacrylonitrile-based synthetic fiber (A) to form a coating film.
The amounts of the quaternary ammonium salt (B) and the non-ionic surfactant (C) adhered are specific amounts relative to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber.
Because specific amounts of the quaternary ammonium salt (B) and the non-ionic surfactant (C) are adhered to the antibacterial polyacrylonitrile-based synthetic fiber, the antibacterial polyacrylonitrile-based synthetic fiber exhibits effects of excellent antibacterial activity and excellent tactile sensation.
Essential and optional components in the antibacterial polyacrylonitrile-based synthetic fiber are hereinafter described.

Polyacrylonitrile-Based Synthetic Fiber (A)

Any acrylonitrile polymers containing 25% by mass or more acrylonitrile-derived structural units may be used to form the polyacrylonitrile-based synthetic fiber (A) without limitation. For example, the acrylonitrile polymer used may contain 25-100% by mass of an acrylonitrile-derived structural unit and 0-75% by mass of a structural unit derived from an additional monomer. The acrylonitrile polymer may contain 95% by mass or less of the acrylonitrile-derived structural unit and 5% by mass or more of a structural unit derived from an additional monomer, may contain 90% by mass or less of the acrylonitrile-derived structural unit and 10% by mass or more of a structural unit derived from an additional monomer, and may contain 30 to less than 85% by mass of the acrylonitrile-derived structural unit and more than 15% by mass and 70% by mass or less of a structural unit derived from an additional monomer.
Said additional monomer may be any monomer copolymerizable with acrylonitrile without limitation. Examples thereof include unsaturated carboxylic acids as and such acrylic acid methacrylic acid and salts thereof, acrylate esters such as methyl acrylate, methacrylate esters such as methyl methacrylate, esters of unsaturated carboxylic acids such as glycidyl methacrylate, vinyl esters such as vinyl acetate and vinyl butyrate, halogen-containing monomers and sulfonate group-containing monomers. These monomers may be used alone or in combination of two or more.
The acrylonitrile polymer may contain 30-80% by mass of an acrylonitrile-derived structural unit, 20-70% by mass of a halogen-containing monomer-derived structural unit and 0-5% by mass of a sulfonate group-containing monomer-derived structural unit in light of heat resistance, flame retardancy and dyeing affinity. The acrylonitrile polymer may contain 35-75% by mass of an acrylonitrile-derived structural unit, 25-65% by mass of a halogen-containing monomer-derived structural unit and 0-5% by mass of a sulfonate group-containing monomer-derived structural unit, or may contain 35-75% by mass of an acrylonitrile-derived structural unit, 24.5-64.5% by mass of a halogen-containing monomer-derived structural unit and 0.5-5% by mass of a sulfonate group-containing monomer-derived structural unit.
Examples of the halogen-containing monomer include halogen-containing vinyl monomers such as vinyl chloride and vinyl bromide and halogen-containing vinylidene monomers such as vinylidene chloride and vinylidene bromide. These halogen-containing monomers may be used alone or in combination of two or more. The halogen-containing monomer may contain one or more monomer selected from the group consisting of vinyl chloride and vinylidene chloride, and may contain vinyl chloride in light of tactile sensation.
Any sulfonate group-containing monomer may be used without limitation. Examples thereof include allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, isoprene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid and metal salts such as sodium salts and amine salts of the foregoing. These sulfonate group-containing monomers may be used alone or in combination of two or more.
The polyacrylonitrile-based synthetic fiber (A) may have any filament fineness without limitation. For example, the filament fineness may be 1 dtex or more and 100 dtex or less, in light of being suitably used for artificial hair, 10 dtex or more and 90 dtex or less, 20 dtex or more and 80 dtex or less, 30 dtex or more and 70 dtex or less or 35 dtex or more and 65 dtex or less.
The polyacrylonitrile-based synthetic fiber (A) may be produced by any method without limitation, and may be produced by, for example, wet spinning. The wet spinning is a method in which a spinning starting solution containing said copolymer is extruded from a spinneret into a coagulation bath to solidify and form a yarn. The wet spinning may include, in addition to the coagulation step, any of a washing step, a drying step, a stretching step and a heat relaxation step.
The polyacrylonitrile-based synthetic fiber (A) may be produced according to the method described above, or may be a commercially available polyacrylonitrile-based synthetic fiber. Examples of the commercially available polyacrylonitrile-based synthetic fiber (A) include “AFRELLE” and “SYC” available from Kaneka Corporation.

Quaternary Ammonium Salt (B)

The quaternary ammonium salt (B) (hereinafter also referred to as “component (B) ”) is represented by formula (1) indicated below:
In formula (1), R¹is an alkyl group with 8-18 carbon atoms; R²to R⁴are each independently a methyl group, an alkyl group with 8-18 carbon atoms, a 3-(trihydroxysilyl) propyl group, a 3-(trimethoxysilyl)propyl group or a benzyl group; n is 1 or 2; and Xⁿ⁻is an inorganic acid ion selected from the group consisting of bromide ions, chloride ions, fluoride ions, hydroxide ions, carbonate ions, sulfate ions, nitrate ions, phosphate ions and borate ions or a monoalkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms or a dialkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms.
In formula (1), in light of excellent antibacterial activity and excellent tactile sensation of the antibacterial polyacrylonitrile-based synthetic fiber, it is preferable that R¹is an alkyl group with 8-18 carbon atoms and R²to R⁴are each a methyl group, or R¹and R²are each an alkyl group with 8-18 carbon atoms and R³and R⁴are each a methyl group, or R¹is an alkyl group with 8-18 carbon atoms, R²is a 3-(trihydroxysilyl)propyl group and R³and R⁴are each a methyl group, or R¹is an alkyl group with 8-18 carbon atoms, R²is a 3-(trimethoxysilyl)propyl group and R³and R⁴are each a methyl group, n may be 1 and Xⁿ⁻may be a chloride ion or a dialkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms.
In formula (1), specific examples of the alkyl group with 8-18 carbon atoms of R¹and R²include octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl and octadecyl groups and alkyl groups which are structural isomers of said alkyl groups. Among these, octyl, decyl, dodecyl and hexadecyl groups are preferable.
The amount of the quaternary ammonium salt (B) adhered may be 0.05% by mass or more and 0.3% by mass or less or 0.1% by mass or more and 0.25% by mass or less relative to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber in light of excellent antibacterial activity and excellent tactile sensation of the antibacterial polyacrylonitrile-based synthetic fiber.

Non-Ionic Surfactant (C)

The non-ionic surfactant (C) (hereinafter also referred to as “component (C) ”) includes a sorbitan fatty acid ester (C1) and a polyoxyethylene triglyceride (C2).

Sorbitan Fatty Acid Ester (C1)

The sorbitan fatty acid ester (C1) is an ester of sorbitan and a fatty acid. Any sorbitan fatty acid esters (C1) may be used without limitation and examples thereof include sorbitan monocaprylate, sorbitan monolaurate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, sorbitan tristearate and the like. Among these, sorbitan monostearate is preferable.

Polyoxyethylene Triglyceride (C2)

The polyoxyethylene triglyceride (C2) is an ester of a fatty acid and a product of addition polymerization of ethylene oxide with a triglyceride. Any polyoxyethylene triglycerides (C2) may be used without limitation and examples thereof include polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil, polyoxyethylene triisostearate and the like. Among these, polyoxyethylene castor oil is preferable.
The amount of the non-ionic surfactant (C) adhered may be 0.15% by mass or more and 0.9% by mass or less or 0.2% by mass or more and 0.6% by mass or less relative to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber in light of excellent antibacterial activity and excellent tactile sensation of the antibacterial polyacrylonitrile-based synthetic fiber.
The content of the sorbitan fatty acid ester (C1) may be any amount without limitation and may be 20% by mass or more and 90% by mass or less or 35% by mass or more and 65% by mass or less relative to the total mass of the non-ionic surfactant (C). The content of the polyoxyethylene triglyceride (C2) may be any amount without limitation and may be 90% by mass or more and 20% by mass or less or 65% by mass or more and 35% by mass or less relative to the total mass of the non-ionic surfactant (C).

Additional Component

The antibacterial polyacrylonitrile-based synthetic fiber may include a component (hereinafter also referred to as “additional component”) other than the polyacrylonitrile-based synthetic fiber (A), the quaternary ammonium salt (B) and the non-ionic surfactant (C) provided that the effects of one or more embodiments of the present invention are not deteriorated. Examples of the additional component include a gloss adjusting agent, a coloring agent such as an organic pigment, an inorganic pigment and a dye, a photostabilizer, a heat stabilizer, a fiber sizing agent, a deodorant, a fragrance, an insect repellent, a crosslinking agent and the like.

Production Method 1 of the Antibacterial Polyacrylonitrile-Based Synthetic Fiber

A first embodiment of a method for producing the antibacterial polyacrylonitrile-based synthetic fiber includes wet-spinning a spinning solution containing an acrylonitrile polymer to obtain a coagulated yarn and bringing a yarn to be treated before drying into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C). The production method of one or more embodiments can produce, as described hereinabove, an antibacterial polyacrylonitrile-based synthetic fiber that has excellent antibacterial activity and excellent tactile sensation and is suitable for artificial hair.
Detailed descriptions are provided hereinbelow on a step (hereinafter also referred to as “coagulation step”) of wet-spinning a spinning solution containing an acrylonitrile polymer to obtain a coagulated yarn, a step (hereinafter also referred to as “contacting step”) of bringing a yarn to be treated before drying into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C) and an arbitrary step.

Coagulation Step

Acrylonitrile Polymer

The acrylonitrile polymer is a starting material for producing a yarn of the polyacrylonitrile-based synthetic fiber (A). One or more embodiments of the acrylonitrile polymer described in the section “(Polyacrylonitrile-based synthetic fiber (A))” above apply to the acrylonitrile polymer.

Spinning Solution

The spinning solution contains the acrylonitrile polymer and an organic solvent. Any organic solvent may be used without limitation and the organic solvent may be a good solvent for an acrylonitrile polymer. Examples of the good solvent for the acrylonitrile polymer include dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), acetone and the like. Among these, acetone may be used in light of versatility. In light of high safety, dimethyl sulfoxide may be used. The spinning solution may contain a small amount of water such as 1.5% by mass or more and 4.8% by mass or less water. Because of this, formation of voids may be prevented.

Additional Additive

The spinning solution may optionally contain an additional additive for improving fiber characteristics provided that the effects of one or more embodiments of the present invention are not deteriorated. Examples of the additional additive include a gloss adjusting agent, a coloring agent such as an organic pigment, an inorganic pigment and a dye, a stabilizer for improving light resistance and heat resistance and the like.

Coagulation Step

The coagulation step is a step in which the spinning solution is ejected through a spinneret into a coagulation solution (coagulation bath) to coagulate and form a yarn (hereinafter such yarn is also referred to as “coagulated yarn”). The coagulation step may be carried out by any procedures without limitation and the procedure may be, for example, a wet spinning according to a conventional manner in which the spinning solution in a starting solution tank is directly ejected into a coagulation solution. The procedure may alternatively be a dry-wet spinning in which the spinning solution is ejected into air through a spinneret and then introduced into a coagulation solution.
The temperature of the spinning solution may be any temperature without limitation provided that the spinning solution in the starting solution tank can be stably kept without change over time, and may be, for example, generally 40° C. or higher and 70° C. or lower.
The coagulation solution may have any composition without limitation and may be, for example, an aqueous solution of a good solvent such as acetone. The good solvent may be at any concentrations without limitation and the concentration may be, for example, 10% by mass or more and 70% by mass or less. When the concentration is less than 10% by mass, coagulation tends to proceed too fast, thereby causing loose coagulation structure and formation of voids in the fiber. The coagulation solution may have any temperature without limitation and the temperature may be, for example, 5° C. or higher and 40° C. or lower.
Any spinneret may be used, as appropriate, according to the fiber cross-section of interest. Any fiber cross-section may be selected without limitation and the fiber cross-section may be any of circular, elliptical, irregular-shaped and the like. The amount of ejection of the spinning solution from the spinneret may be any amount without limitation and may be, for example, 0.1 g/min or more as a flow rate per spin hole. The spinning rate of the spinning solution from the spinneret may be any value without limitation and may be 2 m/min or more and 17 m/min or less in light of industrial productivity.
The coagulated yarn (fiber) passed through the coagulation solution may be, according to a conventional manner, wound onto a winding roller via a sending roller, thereby obtaining an unstretched yarn. Alternatively, an additional step may be followed continuously without winding.

Additional Step

The wet spinning may include a step (hereinafter also referred to as “additional step”) other than the coagulation step provided that the effects of one or more embodiments of the present invention are not deteriorated.
Examples of the additional step include a washing step, a drying step, a stretching step, a heat relaxation step and the like. Examples of the stretching step include a wet stretching step that is carried out before a washing step or after a washing step and before a drying step and a dry stretching step that is carried out after a drying step.
The steps may be performed in any order without limitation. Examples includes a method in which, after the coagulation step, a wet stretching step, a washing step, a drying step, a dry stretching step and a heat relaxation step are carried out in this order or a method in which, after the coagulation step, a washing step, a wet stretching step, a drying step, a dry stretching step and a heat relaxation step are carried out in this order.

Wet Stretching Step

The wet stretching step is a step in which the coagulated yarn is stretched in a stretching bath (hereinafter also referred to as “primary stretching”). The stretching bath used may be an aqueous solution having a lower concentration of a good solvent such as acetone than in the coagulation bath. The stretching bath may have a temperature of 30° C. or higher or 40° C. or higher. The stretch ratio may be any value without limitation and may be 1.5 or more and 8 or less in light of increasing the strength and productivity of the fiber. When the primary stretching is carried out in a water bath, the wet stretching step may be carried out after the washing step described hereinafter or the primary stretching may be carried out at the same time as washing.

Washing Step

The washing step is a step in which a good solvent such as acetone adhered to the yarn after the coagulation step or the wet stretching step is removed. In the washing step, warm water of, for example, 70° C. or higher may be used in light of easy removal of the good solvent.

Drying Step

The drying step is a step in which a yarn is dried to densify the same. The drying may be carried out at any temperature without limitation and the drying temperature may be, for example, 110° C. or higher and 190° C. or lower.

Dry Stretching Step

The dry stretching step is a step in which a yarn is stretched under heating conditions (hereinafter also referred to as “secondary stretching”). The stretching may be carried out at any temperature without limitation and the stretching temperature may be, for example, 110° C. or higher and 190° C. or lower. The stretch ratio may of any value without limitation and the stretch ratio may be, for example, 1 or more and 4 or less, 1.5 or more and 3.5 or less or 1.5 or more and 3 or less.
The total stretch ratio including wet stretching before drying may be 2 or more and 10 or less, 2 or more and 8 or less, 2 or more and 6 or less or 2 or more and 4 or less.

Heat Relaxation Step

The heat relaxation step is a step in which a yarn after dry stretching is relaxed in a high temperature atmosphere. The relaxation ratio may be any value without limitation and the relaxation ratio may be, for example, 5% or more or 8% or more and 20% or less. The heat relaxation may be carried out, for example, under a dry heat atmosphere or a superheated steam atmosphere of 140° C. or higher and 200° C. or lower.

Contacting Step

Yarn to be Treated Before Drying

The yarn to be treated before drying refers to a yarn that has not been dried and thus has not been densified and that is to be brought into contact with the oil agent described hereinafter. The yarn to be treated includes not only the coagulated yarn obtained by the wet spinning but also a yarn obtained after subjecting said yarn to a treatment other than the drying step, the dry stretching step and the heat relaxation step described hereinabove. Specific examples of the yarn to be treated include a coagulated yarn obtained by wet spinning, a yarn obtained after wet stretching and a yarn obtained after washing. Among these, a yarn obtained after washing is preferable in light of preventing an organic solvent from contaminating the oil agent.

Oil Agent

The oil agent contains the quaternary ammonium salt (B) and the non-ionic surfactant (C) described hereinabove. The oil agent used may be a mixed liquid containing the quaternary ammonium salt (B) and the non-ionic surfactant (C) dispersed or dissolved in water.
The oil agent may contain a component (hereinafter also referred to as “additional component”) other than the quaternary ammonium salt (B), the non-ionic surfactant (C) and water provided that the effects of one or more embodiments of the present invention are not deteriorated. Examples of the additional component include a modified silicone; an antistatic agent; a gloss adjusting agent; a coloring agent such as an organic pigment, an inorganic pigment and a dye; a photostabilizer; a heat stabilizer; a fiber sizing agent; a deodorant; a fragrance; an insect repellent; an antibacterial agent: a crosslinking agent and the like.

Manner of Contacting

The yarn to be treated may be brought into contact with the oil agent in any manner without limitation, and examples of the manner include immersion, spraying, application using a shower and application by coating. Among these, immersion is preferable in light of uniform contacting of the components in the oil agent.
The temperature during contacting may be any value without limitation and may be adjusted, as appropriate, within 40° C. or higher and 90° C. or lower according to the state of the yarn to be treated and the desired amount to be adhered.
The time for contacting may also be any value without limitation and may be adjusted, as appropriate, within 1 second or more and 10 minutes or less according to the state of the yarn to be treated and the desired amount to be adhered.
In one or more embodiments, the yarn after the contact treatment may be dried and then subjected to dry stretching. Going through these steps can produce an antibacterial polyacrylonitrile-based synthetic fiber that has excellent antibacterial activity and excellent tactile sensation and is suitable for artificial hair.

Production Method 2 of the Antibacterial Polyacrylonitrile-Based Synthetic Fiber

The second embodiment of the method for producing the antibacterial polyacrylonitrile-based synthetic fiber described above includes bringing a dried polyacrylonitrile-based synthetic fiber (A) into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C) and drying the yarn after the contact treatment.
The production method of one or more embodiments can produce, as described hereinabove, an antibacterial polyacrylonitrile- based synthetic fiber that has excellent antibacterial activity and excellent tactile sensation and is suitable for artificial hair.
Detailed descriptions are provided hereinbelow on a step (hereinafter referred to as “contacting step) for bringing a dried polyacrylonitrile-based synthetic fiber (A) into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C), a step (hereinafter also referred to as “drying step) for drying the yarn after the contact treatment and an arbitrary step.

Contacting Step

One or more embodiments described in the section “(Polyacrylonitrile-based synthetic fiber (A))” above apply to the polyacrylonitrile-based synthetic fiber (A).
The dried polyacrylonitrile-based synthetic fiber (A) is obtained by drying the polyacrylonitrile-based synthetic fiber (A) at, for example, room temperature or higher and 190° C. or lower.
One or more embodiments described in the section “(Oil agent)” above apply to the oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C).
One or more embodiments described in the section “(Manner of contacting)” above apply to the manner for bringing the dried polyacrylonitrile-based synthetic fiber (A) into contact with the oil agent.
However, in the present production method 2, the dried polyacrylonitrile-based synthetic fiber (A) is used as a starting material, and thus the components in the oil agent hardly adhere to the polyacrylonitrile-based synthetic fiber (A). Because of this, the time for contacting may be longer than the time for contacting in <<Production method 1 of the polyacrylonitrile-based synthetic fiber>> antibacterial described hereinabove.

Drying Step

The drying step is a step in which a yarn of the polyacrylonitrile-based synthetic fiber (A) after the contact treatment is dried to densify the same. The drying may be carried out at any temperature without limitation and the drying temperature may be, for example, 110° C. or higher and 190° C. or lower.

Additional Step

The present production method 2 may include a step (hereinafter also referred to as “additional step”) other than the contacting step and the drying step provided that the effects of one or more embodiments of the present invention are not deteriorated. Examples of the additional step include a stretching step, a heat relaxation step and the like. One or more embodiments described in the sections “(Stretching step)” and “(Heat relaxation step)” above apply to the stretching step and the heat relaxation step.

Headdress Product

The headdress product includes the antibacterial polyacrylonitrile-based synthetic fiber described hereinabove.
The headdress product may be any headdress products without limitation and examples thereof include a hair wig, a toupee, a weaving, a hair extension, a hair braid, a hair accessory and doll hair. The headdress product may be formed with only the antibacterial polyacrylonitrile-based synthetic fiber used as artificial hair. Alternatively, the headdress product may be formed with the antibacterial polyacrylonitrile-based synthetic fiber combined with an additional artificial hair fiber and a natural fiber such as human hair and animal hair. Any additional artificial hair fibers may be used without limitation and examples thereof include polyvinyl chloride fibers, nylon fibers, polyester fibers, regenerated collagen fibers and the like.

EXAMPLES

One or more embodiments of the present invention will be further specifically described by way of Examples and Comparative Examples. However, one or more embodiments of the present invention are not limited to those Examples.

Examples 1 to 10 and Comparative Examples 1 to 4

Preparation of Oil Agent

The quaternary ammonium salt (B) indicated below, the non-ionic surfactant (C) indicated below, dimethyl sulfone (DMSO₂) and distilled water were mixed at the amounts indicated in Table 1 below to prepare oil agents 1-10 and comparative oil agents 1-4 which are oil agent aqueous solutions.
The quaternary ammonium salts (B) used were B1-B7 indicated below.
B1: Hexadecyltrimethylammonium chloride
B2: Dodecyltrimethylammonium chloride
B3: Dodecyltrimethylammonium dimethyl phosphate
B4: Dioctyldimethylammonium chloride
B5: Didecyldimethylammonium chloride
B6: Dimethyl(octadecyl) [3-(trihydroxysilyl)propyl]ammonium chloride
B7: Dimethyl(dodecyl) [3-(trimethoxysilyl)propyl]ammonium chloride
The non-ionic surfactants (C) used were C1 and C2 indicated below.
C1: Sorbitan monostearate
C2: polyoxyethylene castor oil

TABLE 1

Quaternary			Distilled
ammonium	Non-ionic	DMSO₂	water
salt(B)	surfactant (C)	% by	% by
Type/% by mass	Type/% by mass	mass	mass

Oil agent 1	B1/0.5	C1 + C2/2.0	2.0	95.5
Oil agent 2	B1/0.5	C1 + C2/4.0	2.0	93.5
Oil agent 3	B1/0.5	C1 + C2/6.0	2.0	91.5
Oil agent 4	B1/0.7	C1 + C2/4.0	2.0	93.3
Oil agent 5	B2/0.5	C1 + C2/4.0	2.0	93.5
Oil agent 6	B3/0.5	C1 + C2/4.0	2.0	93.5
Oil agent 7	B4/0.5	C1 + C2/4.0	2.0	93.5
Oil agent 8	B5/0.5	C1 + C2/4.0	2.0	93.5
Oil agent 9	B6/0.5	C1 + C2/6.0	2.0	91.5
Oil agent 10	B7/0.5	C1 + C2/4.0	2.0	93.5
Comparative	—	C1 + C2/2.0	2.0	94.0
oil agent 1
Comparative	B1/0.5	—	2.0	97.5
oil agent 2
Comparative	B1/0.5	C1 + C2/1.0	2.0	96.5
oil agent 3
Comparative	B1/1.5	C1 + C2/6.0	2.0	90.5
oil agent 4

*The contents of C1 and C2 are C1/C2 = 4/6 in mass ratio.

Preparation of Antibacterial Polyacrylonitrile-Based Synthetic Fibers

An acrylonitrile polymer obtained by copolymerizing 46% by mass of acrylonitrile, 52% by mass of vinyl chloride and 2% by mass of sodium styrenesulfonate was dissolved in dimethyl sulfoxide (DMSO) to prepare a resin solution having a resin concentration of 26.0% by mass and a water concentration of 2.7% by mass. To the resin solution were then added coloring agents that were carbon black, a red dye (C. I. Basic Red 46) and a blue dye (C.I. Basic Blue 41) at 2.1 parts by mass, 0.04 parts by mass and 0.07 parts by mass, respectively, relative to 100 parts by mass of the acrylonitrile polymer. Poly (glycidyl methacrylate) (mass average molecular weight: 12,000) was further added at 0.8 parts by mass relative to 100 parts by mass of the acrylonitrile polymer to prepare a spinning starting solution. The spinning starting solution was extruded into a coagulation bath of a 47% by mass DMSO aqueous solution at 25° C. through a spinneret (hole diameter: 0.3 mm, 100 holes) at a spinning rate of 2 m/min to carry out wet spinning, followed by stretching in a stretching bath of a 50% by mass DMSO aqueous solution at 90° C. at a stretch ratio of 2.1. Washing was then carried out with warm water of 90° C., yarns were immersed in oil agent vessels (60° C.) respectively containing the oil agents indicated in Table 1 for 1 to 3 seconds to impregnate the yarns with the oil agents, then dried at 140° C., stretched at a ratio of 3 and subjected to a 27% relaxation treatment at 155° C. to prepare antibacterial polyacrylonitrile-based synthetic fibers of Examples 1-10 and Comparative Examples 1-4 indicated in Table 2 below having a filament fineness of approximately 46 dtex.
In Table 2, the amount “% owf” of the quaternary ammonium salt (B) and the non-ionic surfactant (C) adhered means the percent by mass of the quaternary ammonium salt (B) or the non-ionic surfactant (C) relative to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber. The amounts of the quaternary ammonium salt (B) and the non-ionic surfactant (C) adhered were calculated from the amounts of the quaternary ammonium salt (B) and the non-ionic surfactant (C) extracted from the prepared antibacterial polyacrylonitrile-based synthetic fibers.
Although not indicated in Table 2, the contents of C1 and C2 in Examples 1-10 and Comparative Examples 1-4 are C1/C2=4/6 in mass ratio.

Evaluation

The obtained antibacterial polyacrylonitrile-based synthetic fiber was evaluated for antibacterial activity and tactile sensation according to the methods indicated below. The results are indicated in Table 2.

Antibacterial Activity

According to JIS L 1902:2015 (Textiles-Determination of antibacterial activity and efficacy of textile products (absorption method)), the antibacterial polyacrylonitrile-based synthetic fiber was measured for antibacterial activity value. Staphylococcus aureus was used for the test. In order to prevent change of form of samples, the samples were subjected to the test without high-pressure sterilization. The “certification standards of SEK mark textile products” indicate that the antibacterial activity value of 2.2 or more means antibacterial and deodorant effects.

Tactile Sensation

Three people who had been working in cosmetic evaluation of toupees for three years or more carried out the sensory assessment of fiber bundle samples having a total fineness of 1,200,000-1,3000,000 dtex and comprehensively judged tactile sensation such as softness, sliminess and moistness on the three-level scale indicated below compared to AFRELLE (polyacrylonitrile-based synthetic fiber, available from Kaneka Corporation, 46 dtex).
A: (Very good): Better tactile sensation than AFRELLE
B: (Good): Tactile sensation equivalent to that of AFRELLE
C: (Poor): Poorer tactile sensation than AFRELLE

TABLE 2

Quaternary	Non-ionic
ammonium	surfactant
salt (B)	(C)	Antibacterial	Tactile
Type/% owf	Type/% owf	activity	sensation

Example 1	Oil agent 1	B1/0.20	C1 + C2/0.20	2.5	B
Example 2	Oil agent 2	B1/0.20	C1 + C2/0.27	3.2	A
Example 3	Oil agent 3	B1/0.20	C1 + C2/0.60	4.5	B
Example 4	Oil agent 4	B1/0.24	C1 + C2/0.27	3.2	A
Example 5	Oil agent 5	B2/0.20	C1 + C2/0.40	4.4	A
Example 6	Oil agent 6	B3/0.20	C1 + C2/0.35	4.3	A
Example 7	Oil agent 7	B4/0.20	C1 + C2/0.40	4.7	A
Example 8	Oil agent 8	B5/0.20	C1 + C2/0.38	4.6	A
Example 9	Oil agent 9	B6/0.20	C1 + C2/0.60	6.0	B
Example 10	Oil agent 10	B7/0.20	C1 + C2/0.40	5.8	A
Comparative	Comparative	—	C1 + C2/0.20	0.3	B
Example 1	oil agent 1
Comparative	Comparative	B1/0.20	—	1.9	C
Example 2	oil agent 2
Comparative	Comparative	B1/0.20	C1 + C2/0.10	2.0	B
Example 3	oil agent 3
Comparative	Comparative	B1/0.40	C1 + C2/0.30	3.9	C
Example 4	oil agent 4

It is found from Table 2 that the polyacrylonitrile-based synthetic fibers of Examples 1-10 have high antibacterial activity while also achieving satisfactory tactile sensation as artificial hair, while Comparative Examples 1-4 which have an extremely low amount of the quaternary ammonium salt adhered or have the amount adhered of above 0.4% by mass or have the amount of the non-ionic surfactant adhered of 0.1% by mass or less cannot achieve both satisfactory tactile sensation as artificial hair and antibacterial activity.
Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present disclosure. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims

1. An antibacterial polyacrylonitrile-based synthetic fiber, comprising:

a polyacrylonitrile-based synthetic fiber (A);

a quaternary ammonium salt (B) represented by following formula (1):

wherein in the formula (1), R¹is an alkyl group with 8-18 carbon atoms;

R²to R⁴are each independently a methyl group, an alkyl group with 8-18 carbon atoms, a 3-(trihydroxysilyl)propyl group, a 3-(trimethoxysilyl)propyl group or a benzyl group;

n is 1 or 2; and

xⁿ⁻is an inorganic acid ion selected from the group consisting of bromide ions, chloride ions, fluoride ions, hydroxide ions, carbonate ions, sulfate ions, nitrate ions, phosphate ions and borate ions or a monoalkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms or a dialkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms; and

a non-ionic surfactant (C),

wherein the quaternary ammonium salt (B) and the non-ionic surfactant (C) are adhered to the polyacrylonitrile-based synthetic fiber (A),

wherein the non-ionic surfactant (C) contains a sorbitan fatty acid ester (C1) and a polyoxyethylene triglyceride (C2),

wherein an amount of the quaternary ammonium salt (B) adhered to the polyacrylonitrile-based synthetic fiber (A) is 0.05% by mass or more and 0.3% by mass or less relative to a total mass of the antibacterial polyacrylonitrile-based synthetic fiber, and

wherein the amount of the non-ionic surfactant (C) adhered to the polyacrylonitrile-based synthetic fiber (A) is 0.15% by mass or more and 0.9% by mass or less relative to the total mass of the antibacterial polyacrylonitrile-based synthetic fiber.

2. The antibacterial polyacrylonitrile-based synthetic fiber according to claim 1, wherein

R¹is an alkyl group with 8-18 carbon atoms and R²to R⁴are each a methyl group, or R¹and R²are each an alkyl group with 8-18 carbon atoms and R³and R⁴are each a methyl group, or R¹is an alkyl group with 8-18 carbon atoms, R²is a 3-(trihydroxysilyl)propyl group and R³and R⁴are each a methyl group, or R¹is an alkyl group with 8-18 carbon 3-atoms, R²is a 3-(trimethoxysilyl)propyl group and R³and R⁴are each a methyl group;

n is 1; and

Xⁿ⁻is a chloride ion or a dialkyl phosphate ester ion having an alkyl group with 1-3 carbon atoms.

3. The antibacterial polyacrylonitrile-based synthetic fiber according to claim 1, wherein a content of the sorbitan fatty acid ester (C1) is 20% by mass or more and 90% by mass or less relative to a total mass of the non-ionic surfactant (C).

4. The antibacterial polyacrylonitrile-based synthetic fiber according to claim 1, having a filament fineness of 1 dtex or more and 100 dtex or less.

5. An artificial hair comprising the antibacterial polyacrylonitrile-based synthetic fiber according to claim 1.

6. A headdress product, comprising the antibacterial polyacrylonitrile-based synthetic fiber according to claim 1.

7. The headdress product according to claim 6, wherein the headdress product is one product selected from the group consisting of hair wigs, toupees, weavings, hair extensions, hair braids, hair accessories and doll hair.

8. A method for producing the antibacterial polyacrylonitrile-based synthetic fiber according to claim 1, comprising:

wet-spinning a spinning an solution containing acrylonitrile polymer to obtain a coagulated yarn; and

bringing a yarn comprising the coagulated yarn into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C), before drying the yarn.

9. A method for producing the antibacterial polyacrylonitrile-based synthetic fiber according to claim 1, comprising:

performing a contact treatment to the dried polyacrylonitrile-based synthetic fiber (A) to obtain a contact-treated polyacrylonitrile-based synthetic fiber (A), wherein in the contact treatment, the dried polyacrylonitrile-based synthetic fiber (A) is brought into contact with an oil agent containing the quaternary ammonium salt (B) and the non-ionic surfactant (C); and

after the performing of the contact treatment, drying a yarn of the contact-treated polyacrylonitrile-based synthetic fiber (A).