Polyacrylonitrile wig fiber, method of production and use thereof

Abstract

The application discloses a polyacrylonitrile wig fiber, a preparation method and application thereof, and the preparation method comprises the following steps: (1) preparing a polyacrylonitrile solution containing a color correcting agent and a stabilizer; (2) mixing and dispersing dimethylacetamide with a functional additive, and then adding the polyacrylonitrile solution and a dispersant to disperse, so as to obtain a functional slurry; (3) mixing the polyacrylonitrile solution in the step (1) with the functional slurry in the step (2), so as to obtain a spinning solution, the spinning solution is sprayed out through a spinneret to spin, and the polyacrylonitrile wig fiber is obtained. The preparation method can obtain the natural color and colored wig fibers with good spinnability, excellent indexes, high whiteness of the natural color fibers, uniform color of the colored fibers, good color fastness, good dispersibility, good fluffiness and strong reality.

Description

Technical Field

[0001] This invention belongs to the field of imitation wig fibers, specifically, it relates to a polyacrylonitrile wig fiber, its preparation method, and its uses. Background Technology

[0002] Wigs are products made from human hair or other raw materials such as cow hair, wool, ramie, plant fibers, synthetic nylon, and polyester fibers through a series of processing steps. Their main purpose is to meet the needs of fashionable hairstyles and other practical functional requirements, helping consumers enhance and beautify their appearance. Wig consumption possesses both the product attributes of clothing and accessories, and the service attributes of beauty and hairdressing. The demand for wigs in China is rapidly increasing, driven by both the demand for fashionable hairstyles and the growing number of people experiencing hair loss.

[0003] As a raw material for wigs, synthetic fibers are not constrained by resources, are industrially produced, and are low-cost and inexpensive, making them the mainstream in the wig market. Furthermore, they can be readily customized with various colors and varieties to meet market demands, resulting in high added value. To make the properties of synthetic fibers closer to natural hair, researchers are constantly developing new fiber varieties for wigs and studying methods to modify existing fibers. Commonly used synthetic fibers in wig production include polyvinyl chloride (PVC)-based fibers, polyacrylonitrile (PAN)-based fibers, polyester (mainly PET)-based fibers, polypropylene (PP)-based fibers, and protein-based fibers.

[0004] Polyacrylonitrile (PAN)-based fibers possess excellent mechanical properties, are easy to comb, and offer high cost-effectiveness, leading to numerous studies exploring ways to further enhance their suitability as wig fibers. For example:

[0005] CN202099617U discloses an artificial hair wig made by attaching nano-TiO2 particles to the surface of polyacrylonitrile fibers and uniformly dispersing sodium alginate powder inside.

[0006] CN109577012A discloses a method for preparing high-strength, stain-resistant wig fibers. The method involves mixing polyacrylonitrile fibers with a sodium hydroxide solution and stirring to obtain hydrolyzed polyacrylonitrile fibers; mixing protein fibers with a protease to obtain a protein fiber hydrolysate; mixing aramid fibers with a sulfuric acid solution and stirring to obtain an aramid concentrate; mixing nano-zinc oxide with water, adding a coupling agent, and stirring to obtain a nano-zinc oxide mixture; mixing the hydrolyzed polyacrylonitrile fibers with the protein fiber hydrolysate, adding the nano-zinc oxide mixture, mixing and soaking, filtering, and then pre-drying and baking to obtain pretreated polyacrylonitrile fibers; mixing the pretreated polyacrylonitrile fibers with the aramid concentrate, adding water and the nano-zinc oxide mixture, stirring and mixing, filtering, and then pre-drying and baking to obtain high-strength, initial-grade wig fibers.

[0007] CN112376264 A discloses a method for modifying flame-retardant and breathable polyacrylonitrile fibers for wigs. The method involves adding amination-modified polyacrylonitrile fibers to a zinc chloride aqueous solution, reacting the fibers, removing them, washing them with water, and drying them to obtain zinc ion chelate-modified flame-retardant polyacrylonitrile fibers. The obtained zinc ion chelate-modified flame-retardant polyacrylonitrile fibers are then reacted in a hydrogen peroxide solution, removed, rinsed with water, and dried to obtain weakly oxidized flame-retardant polyacrylonitrile fibers. Distilled water is added to zinc acetate dihydrate to dissolve the fibers, sodium hydroxide is added dropwise to produce a precipitate, and the precipitate is dissolved by further dropwise addition. Urea and a polyurethane waterproof and breathable solution are then added, immersing the obtained weakly oxidized flame-retardant polyacrylonitrile fibers in the solution. After swelling treatment, the fibers are washed with water until neutral, pre-dried, and then baked at high temperature to obtain flame-retardant and breathable modified polyacrylonitrile fibers.

[0008] The above mainly concerns finishing techniques for polyacrylonitrile fibers. Currently, there is relatively little research on how to improve the front-end spinning method to prepare polyacrylonitrile fibers that make them more realistic in terms of feel and appearance when used as wigs.

[0009] In view of this, the present invention is proposed. Summary of the Invention

[0010] The technical problem to be solved by this invention is to overcome at least one of the shortcomings of the prior art, and to provide a polyacrylonitrile wig fiber, a preparation method thereof, and its uses. The preparation method of this invention can obtain natural-colored and colored imitation wig fibers with good spinnability and excellent properties. The natural-colored fibers have high whiteness, and the colored fibers have uniform color, good color fastness, and are soft, smooth, well-dispersible, fluffy, and highly realistic.

[0011] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0012] In a first aspect, the present invention provides a method for preparing polyacrylonitrile wig fibers, comprising:

[0013] (1) Prepare a polyacrylonitrile solution containing color corrector and stabilizer;

[0014] (2) After mixing and dispersing dimethylacetamide with functional additives, polyacrylonitrile solution and dispersant are added for further dispersion to obtain functional slurry;

[0015] (3) Mix the polyacrylonitrile solution in (1) with the functional slurry in (2) to obtain the spinning solution, which is then spun through a spinneret to obtain polyacrylonitrile wig fibers.

[0016] In the preparation method of polyacrylonitrile wig fibers of the present invention, a color corrector and a stabilizer are pre-added to the polyacrylonitrile solution. The color corrector can increase the whiteness of the fiber, preventing yellowing when preparing natural-colored fibers; when preparing colored fibers, it can improve the consistency between the fiber color and the color card, avoiding color deviation and ensuring that the product color meets customer requirements. The stabilizer can ensure the stable luster of the finished imitation wig fibers, preventing dullness and yellowing.

[0017] The polyacrylonitrile solution added in step (2) is derived from step (1) and is a polyacrylonitrile solution containing color corrector and stabilizer.

[0018] In a further embodiment, in step (1), the color corrector is selected from one or two of blue pigment and purple pigment;

[0019] Preferably, the colorant is a mixture of blue and purple pigments;

[0020] Preferably, the mass ratio of blue pigment to purple pigment in the mixture is 1:1-2; more preferably 1:1.5.

[0021] Preferably, the fiber content of blue pigment is 0.0025%-0.0045%, and the fiber content of purple dye is 0.0045%-0.0065%.

[0022] More preferably, the proportion of blue pigment fiber is 0.0035%, and the proportion of purple dye fiber is 0.0053%.

[0023] In this invention, the addition of a color corrector increases the sensory whiteness of the fiber, preventing it from yellowing. The color corrector absorbs yellow light, thus reducing the yellow tint and increasing the whiteness of the fiber. By controlling the mass ratio of blue to purple pigment within the range of 1:1-2, the whiteness of the fiber can be improved. The optimal ratio of blue to purple pigment in the color corrector is 1:1.5, resulting in the best hue. This also improves the consistency between the fiber color and the color chart during the preparation of colored fibers, avoiding color deviation and ensuring that the product color meets customer requirements.

[0024] It should be noted that the fiber percentage of a certain substance mentioned in this invention refers to the mass percentage of the substance in the prepared fiber.

[0025] In a further embodiment, in step (1), the stabilizer is selected from one or more of oxalic acid, citric acid, and acetic acid;

[0026] Preferably, the stabilizer is oxalic acid;

[0027] Preferably, the fiber content of the stabilizer is 0.02-0.04%, more preferably 0.025-0.035%, and even more preferably 0.03%.

[0028] After the polyacrylonitrile solution is prepared, a stabilizer is added in this invention to ensure the stable luster of the finished imitation wig fiber and avoid dullness or yellowing. The main factors affecting the color of the spinning solution are oxidation, iron ions, and alkaline substances. In this invention, a binary moderately strong acid is used to improve the color of the solution and acts as a stabilizer. It forms salts with ions that are detrimental to color (especially Fe ions), acting as a metal chelating agent to avoid the DMAC cycle that can cause colored decomposition. This reduces the degradation and discoloration of the solution (fiber) caused by high temperature and prolonged residence time.

[0029] In a further embodiment, in step (1), acrylonitrile and vinyl acetate undergo an aqueous suspension polymerization reaction to obtain a polymer, which is then filtered and dried to obtain polyacrylonitrile powder; then the polyacrylonitrile powder is dissolved in dimethylacetamide, heated, and filtered to obtain a polyacrylonitrile solution.

[0030] Preferably, the mass concentration of acrylonitrile is 91.5-92%, and the mass concentration of vinyl acetate is 8-8.5%.

[0031] Preferably, the temperature of the aqueous suspension polymerization reaction is 59–61°C, and the pH is 2.5–3.5;

[0032] Preferably, when preparing the polyacrylonitrile solution, the mass percentage of polyacrylonitrile powder is 23-27%, and the mass percentage of dimethylacetamide is 73-77%.

[0033] In a further embodiment, in step (2), the functional additives include at least one of colored pigments, antibacterial agents, flame retardants, antistatic agents, and animal proteins.

[0034] A further option is that the functional additive is a colored pigment, or an antibacterial agent, or a combination of a colored pigment and an antibacterial agent.

[0035] In this invention, functional additives are added according to actual needs. For example, when preparing natural-colored antibacterial fibers, only antibacterial agents may be added; when preparing colored fibers, only colored pigments may be added; and when preparing colored antibacterial fibers, both colored pigments and antibacterial agents may be added simultaneously.

[0036] In a further embodiment, the functional slurry contains 6.7%-11.6% by mass of colored pigments, preferably 9.1%.

[0037] In a further embodiment, the colored pigment accounts for 1-2% of the mass of the fiber, preferably 1.5%.

[0038] The colored pigments described in this invention can be any type of pigment used in spinning in the prior art, and can be any desired color and type. For example, the colored pigments can be black, brown, coffee, pink, orange, etc.

[0039] In a further embodiment, the colored pigment is selected from organic pigments or inorganic pigments;

[0040] In a further embodiment, the colored pigment is selected from quinacridones, phthalocyanines, and anthraquinones;

[0041] In a further embodiment, the functional slurry contains an antibacterial agent at a mass percentage of 3.8-6.2%, preferably 4.8%.

[0042] In a further embodiment, the antibacterial agent accounts for 0.6-1.0% of the fiber by mass, preferably 0.8%;

[0043] In a further embodiment, the antibacterial agent includes organic antibacterial agents and inorganic antibacterial agents;

[0044] In a further embodiment, the organic antibacterial agent is selected from at least one of phenols, aldehydes, quaternary ammonium salts, bisphenols, thiols, esters, and chlorine dioxide; the organic antibacterial agent is soluble in dimethylacetamide;

[0045] A further option is to select at least one inorganic antibacterial agent from silver ion, copper ion, and zinc ion antibacterial agents;

[0046] In a further embodiment, the inorganic antibacterial agent is at the nanoscale, with a particle size of less than 5 μm.

[0047] In a further embodiment, in step (2), the mass percentage of dispersant in the functional slurry is 1.2%-3.7%, preferably 2.4%;

[0048] Preferably, the dispersant accounts for 0.2-0.6% of the fiber by mass, more preferably 0.4%;

[0049] Preferably, the dispersant includes at least one of a titanium-containing compound and a silicon-containing compound;

[0050] Preferably, the dispersant includes one or more of nano-sized titanium dioxide, nano-sized silicon dioxide, and nano-sized silicon monoxide.

[0051] In this invention, nanoscale titanium-containing and silicon-containing compound dispersants are used, which exhibit superior performance compared to conventional dispersants. Furthermore, controlling the particle size of the dispersant to be less than 700 nm in this invention is beneficial for improving the dispersion effect.

[0052] In a further step, after obtaining the functional slurry in step (2), it needs to be ground for 6 to 8 hours; then the functional slurry is added to the pre-spinning adhesive supply system by pre-spinning injection and mixed with the polyacrylonitrile solution in step (1) for spinning.

[0053] In a further embodiment, in step (3), the spinneret has circular spinneret holes with a number of 8,000-10,000 holes and a diameter of 0.15-0.22 mm for each hole; preferably, the spinneret has 9,000 holes and a diameter of 0.2 mm for each hole.

[0054] In this invention, the fineness is designed to be 45-52D, and the total fineness is 115-144KTEX, preferably 48D, with a total fineness of 130KTEX. The 48D specification is closer to the thickness of human hair, and has elasticity, good luster, and smoothness, which is beneficial for the combing and production of downstream wig products.

[0055] Alternatively, in step (3), the spinneret holes are flat, with a length-to-width ratio of 3-5:1; preferably, the length-to-width ratio of a single hole is 4:1; preferably, the number of holes is 5000-7000; more preferably, the number of holes is 6000.

[0056] This invention uses a spinneret with flat spinneret holes and controls the aspect ratio of each hole within a suitable range to produce wig-like fibers with an elliptical cross-section similar to animal hair, resulting in a more fluffy effect and better meeting the needs of individualized users.

[0057] In this design, the fineness is 45-52D, and the total fineness is 96-134KTEX, with 48D and a total fineness of 115KTEX being preferred. The elliptical cross-section of the imitation hair wig fiber results in a more fluffy texture, better dispersion, a more defined shape, greater resistance to deformation, and excellent elasticity.

[0058] In a further embodiment, in step (3), a wet two-step spinning process is adopted, wherein: the coagulation bath is dimethylacetamide, the concentration of the coagulation bath is 47-55%, preferably 51%; the coagulation bath temperature is 35-45℃, preferably 40℃; the draw ratio is 4-5 times, preferably 4.5 times; and the setting pressure is 260-340KPA, preferably 300KPA.

[0059] The wig-like fibers prepared by this invention are non-curly, which is beneficial for the combing and finishing of downstream wigs.

[0060] A further proposed solution includes an oiling step after spinning. The oiling agent used is a mixture of nonionic surfactant, cationic surfactant and water. The mass percentage of nonionic surfactant is 40-50%, the mass percentage of cationic surfactant is 20-30%, and the mass percentage of water is 25-35%.

[0061] Preferably, in the compound, the mass percentage of nonionic surfactant is 45%, the mass percentage of cationic surfactant is 25%, and the mass percentage of water is 30%.

[0062] Preferably, the nonionic surfactant is selected from one or more of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyol polyoxyethylene ether fatty acid ester, alkylolamide, polyol monofatty acid ester, glycerol fatty acid ester, alkylphenol polyoxyethylene ether, lauramide monoethanolamine, and glyceryl monolaurate.

[0063] Preferably, the nonionic surfactant is one or more of alkylphenol polyoxyethylene ether, high carbon fatty alcohol polyoxyethylene ether, and fatty acid polyoxyethylene ester.

[0064] Preferably, the cationic surfactant is selected from one or more of amine salts, quaternary ammonium salts, and fatty alcohols;

[0065] Preferably, the amine salts include primary amine salts, secondary amine salts, and tertiary amine salt surfactants; the hydrophobic group has a carbon number between 12 and 18 and is a hydrochloride or acetate; for example, octadecyl amine acetate.

[0066] Preferably, the quaternary ammonium salts include alkyl quaternary ammonium salts;

[0067] Preferably, the alkyl quaternary ammonium salt is selected from one or more of alkyl dimethyl benzyl ammonium chloride and alkyl dimethyl hydroxyethyl ammonium chloride.

[0068] Polyacrylonitrile fibers lack grease and wax on their surface, and the cyano groups (-CN) on their macromolecular chains are highly polar, resulting in strong intermolecular forces and a high coefficient of friction. This makes them prone to static electricity during post-processing, leading to problems such as roller wrapping, which hinders further textile processing. The oiling agent used in this invention is a compound of nonionic surfactant, cationic surfactant, and water, with controlled mass ratios of the three. This compound coats the fiber surface with an oil film, giving the fiber a smooth and soft feel, significantly improving its antistatic properties, resulting in a soft, smooth, and well-dispersible feel, similar to human hair. In contrast, fibers prepared using other types of oiling agents tend to be rougher, less soft, and produce a hissing sound when rubbed, with a significantly different feel from human hair.

[0069] Preferably, the pH of the oil is 3.5-5.5, more preferably 4.5.

[0070] Preferably, the solid content of the oil is 70-74%, more preferably 72%.

[0071] Preferably, the oiling agent accounts for 0.4-0.5% of the fiber mass, more preferably 0.45%.

[0072] Preferably, in the oiling step, the temperature of the oiling tank is 60-70℃, more preferably 65℃.

[0073] Secondly, the present invention provides a polyacrylonitrile wig fiber obtained by the preparation method described above;

[0074] Preferably, the polyacrylonitrile wig fiber has a fineness of 48-52 dtex, a breaking strength of 1.5-2.5 CN / dtex, a breaking elongation of 30-40%, a boiling water shrinkage rate of <2%, an oil content of 0.4%, and a fiber whiteness of 50-60.

[0075] Thirdly, the present invention provides a preparation method as described above or the use of the polyacrylonitrile wig fibers as described above in wig products.

[0076] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0077] 1. In the preparation method of polyacrylonitrile wig fibers of the present invention, a color corrector and a stabilizer are pre-added to the polyacrylonitrile solution. The color corrector can increase the whiteness of the fiber, preventing yellowing of the fiber color when preparing natural-colored fibers; when preparing colored fibers, it can improve the consistency between the fiber color and the color card, avoiding color deviation and ensuring that the product color meets customer requirements. The stabilizer can ensure the stable luster of the finished imitation wig fibers, avoiding dullness or yellowing.

[0078] 2. In the preparation method of the present invention, functional additives, such as pigments and antibacterial agents, are first prepared into a functional slurry with solvents, dispersants, and polyacrylonitrile solutions. This can ensure that the functional additives are dispersed more evenly and that the color of the fiber products is more uniform.

[0079] 3. In the preparation method of this invention, a special spinneret is designed to make the fiber product more closely resemble real hair. On the one hand, when the spinneret orifice is circular, the diameter of a single orifice is controlled to be 0.15-0.22 mm, resulting in a fiber fineness of 45-52D, a total fineness of 96-134 KTEX, and a total fineness of 115 KTEX, which is closer to the thickness of real hair. On the other hand, the spinneret orifice is designed to be flat, with a length-to-width ratio of 1:3-1:5, which can produce fibers with an elliptical cross-section. The resulting product is more fluffy, has good dispersibility, a firm texture, resistance to deformation, and excellent elasticity, meeting the consumption needs of special groups.

[0080] 4. In the preparation method of the present invention, the choice of oiling agent in the fiber production process is different from that of conventional fibers. Instead, a compound of nonionic surfactant and cationic surfactant is used as the oiling agent, which can improve the ability to penetrate into the fiber, further improve the processability of post-finishing, and improve the heat treatment effect.

[0081] In summary, the preparation method of the present invention can produce both natural-colored fibers and colored fibers with a complete color spectrum. The fibers have a firm and uniform color, a soft and smooth feel, good dispersibility, high similarity to real hair, and strong simulation. Furthermore, the fibers can be endowed with antibacterial, flame-retardant and other properties by different functional additives such as antibacterial agents and flame retardants.

[0082] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0083] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0084] Figure 1 This is a cross-sectional view of a fiber with a spinneret aspect ratio of 2:1;

[0085] Figure 2 This is a cross-sectional view of a fiber with a spinneret aspect ratio of 3:1;

[0086] Figure 3 This is a cross-sectional view of a fiber with a spinneret aspect ratio of 4:1;

[0087] Figure 4 This is a cross-sectional view of a fiber with a spinneret aspect ratio of 5:1;

[0088] Figure 5 This is a cross-sectional view of a fiber with a spinneret aspect ratio of 6:1.

[0089] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0090] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0091] The following standards refer to textile terminology and testing methods:

[0092] GB / T4146—84-Textile Terminology (Chemical Fiber Section)

[0093] GB6529—86-Standard Atmospheres for Conditioning and Testing of Textiles

[0094] GB8170—87 Rules for Rounding Off Numerical Values

[0095] GB / T14334—93-Sampling Method for Synthetic Short Fibers

[0096] GB / T14335—93-Test Method for Linear Density of Synthetic Short Fibers

[0097] GB / T14337—93-Test Methods for Breaking Strength and Elongation at Break of Synthetic Short Fibers

[0098] GB / T14338—93-Test Method for Crimping Properties of Synthetic Short Fibers

[0099] GB / T14339—93-Test Methods for Defects in Synthetic Short Fibers

[0100] GB / T14341—93-Test Method for Moisture Regain of Synthetic Staple Fibers

[0101] FZ01018—92-Textile Terminology (General Section for Textile Materials and Products)

[0102] Example 1: Preparation of natural-colored antibacterial fibers

[0103] (1) Preparation of a polyacrylonitrile solution containing color corrector and stabilizer, specifically including:

[0104] Acrylonitrile (91.5%) and vinyl acetate (8%) were subjected to an aqueous suspension polymerization reaction at a controlled temperature of 60°C and pH of 3.0 to obtain a polymer. The polymer was then filtered and dried to obtain polyacrylonitrile powder. The polyacrylonitrile powder was then dissolved in dimethylacetamide, heated, and filtered to obtain a polyacrylonitrile solution. The polyacrylonitrile solution contained 25% polyacrylonitrile powder and 75% dimethylacetamide.

[0105] A stabilizer and a color corrector are added to a polyacrylonitrile solution. The stabilizer is oxalic acid, and the fiber content is 0.03%. The color corrector is a mixture of blue and purple pigments, with a mass ratio of blue to purple pigments of 1:1.5. The fiber content of the blue pigment is 0.0035%, and the fiber content of the purple dye is 0.0053%. A polyacrylonitrile solution containing the color corrector and stabilizer is obtained.

[0106] (2) Preparation of functional slurry, specifically including:

[0107] Dimethylacetamide was mixed and dispersed with an antibacterial agent, then polyacrylonitrile solution and dispersant were added for further dispersion, and the mixture was ground for 6 hours to obtain a functional slurry.

[0108] The antibacterial agent is nano-silver ions with a particle size of less than 5 μm. The dispersant is nano-sized titanium dioxide, and the polyacrylonitrile solution is the polyacrylonitrile solution containing color corrector and stabilizer prepared in step (1). In the functional slurry, the mass percentage of the antibacterial agent is 4.8%, and the mass percentage of the dispersant is 2.4%.

[0109] (3) Polyacrylonitrile wig fibers are prepared using a wet two-step process, specifically including:

[0110] The functional slurry prepared in step (2) is added to the pre-spinning adhesive supply system by pre-spinning injection and mixed with the polyacrylonitrile solution prepared in step (1) to form a spinning adhesive solution. The solution is then sprayed out through a spinneret for spinning, formed in a coagulation bath, washed with water, stretched, oiled, dried, and collected to obtain polyacrylonitrile wig fibers.

[0111] The spinneret has round holes with a diameter of 0.2 mm and 9000 holes. The designed fiber fineness is 48D and the total fineness is 130KTEX.

[0112] The coagulation bath was dimethylacetamide with a concentration of 51%; the coagulation bath temperature was 40℃; the draw ratio was 4.5 times; and the setting pressure was 300 kPa.

[0113] The oiling agent selected for the oiling process is a compound of alkylphenol polyoxyethylene ether, alkyl dimethyl benzyl ammonium chloride, and water, wherein the mass percentage of alkylphenol polyoxyethylene ether is 45%, the mass percentage of quaternary ammonium salt is 25%, and the mass percentage of water is 30%. The oiling agent has a pH of 4.5 and a solid content of 72%; the oiling tank temperature is 65℃; and the oiling agent dosage is 0.45% of the fiber mass.

[0114] Example 2: Preparation of Colored Fibers

[0115] (1) Preparation of a polyacrylonitrile solution containing color corrector and stabilizer, specifically including:

[0116] Acrylonitrile (91.5%) and vinyl acetate (8%) were subjected to an aqueous suspension polymerization reaction at a controlled temperature of 60°C and pH of 3.0 to obtain a polymer. The polymer was then filtered and dried to obtain polyacrylonitrile powder. The polyacrylonitrile powder was then dissolved in dimethylacetamide, heated, and filtered to obtain a polyacrylonitrile solution. The polyacrylonitrile solution contained 25% polyacrylonitrile powder and 75% dimethylacetamide.

[0117] A stabilizer and a color corrector are added to a polyacrylonitrile solution. The stabilizer is oxalic acid, and the fiber content is 0.03%. The color corrector is a mixture of blue and purple pigments, with a mass ratio of blue to purple pigments of 1:1.5. The fiber content of the blue pigment is 0.0035%, and the fiber content of the purple dye is 0.0053%. A polyacrylonitrile solution containing the color corrector and stabilizer is obtained.

[0118] (2) Preparation of functional slurry, specifically including:

[0119] Dimethylacetamide was mixed and dispersed with a colored pigment (red), then polyacrylonitrile solution and dispersant were added for further dispersion, and the mixture was ground for 6 hours to obtain a functional slurry.

[0120] In the functional slurry, the colored pigment (red) accounts for 9.1% by mass, representing 1.5% of the fiber mass. The antibacterial agent is nano-silver ions with a particle size of less than 5 μm. The dispersant is nano-sized titanium dioxide, and the polyacrylonitrile solution is the polyacrylonitrile solution containing color corrector and stabilizer prepared in step (1). In the functional slurry, the antibacterial agent accounts for 4.8% by mass, and the dispersant accounts for 2.4% by mass.

[0121] (3) Polyacrylonitrile wig fibers are prepared using a wet two-step process, specifically including:

[0122] The functional slurry prepared in step (2) is added to the pre-spinning adhesive supply system by pre-spinning injection and mixed with the polyacrylonitrile solution prepared in step (1) to form a spinning adhesive solution. The solution is then sprayed out through a spinneret for spinning, formed in a coagulation bath, washed with water, stretched, oiled, dried, and collected to obtain polyacrylonitrile wig fibers.

[0123] The spinneret has flat orifices with a length-to-width ratio of 1:4 and a total of 6,000 orifices. The designed fiber fineness is 48D and the total fineness is 115KTEX.

[0124] The coagulation bath was dimethylacetamide with a concentration of 51%; the coagulation bath temperature was 40℃; the draw ratio was 4.5 times; and the setting pressure was 300 kPa.

[0125] The oiling agent selected for the oiling process is a compound of alkylphenol polyoxyethylene ether, alkyl dimethyl hydroxyethyl ammonium chloride, and water, wherein the mass percentage of alkylphenol polyoxyethylene ether is 45%, the mass percentage of quaternary ammonium salt is 25%, and the mass percentage of water is 30%. The oiling agent has a pH of 4.5 and a solid content of 72%; the oiling tank temperature is 65℃; and the oiling agent dosage is 0.45% of the fiber mass.

[0126] Example 3: Preparation of colored antibacterial fibers

[0127] (1) Preparation of a polyacrylonitrile solution containing color corrector and stabilizer, specifically including:

[0128] Acrylonitrile (92%) and vinyl acetate (8.5%) were subjected to an aqueous suspension polymerization reaction at a controlled temperature of 59°C and pH of 3.5 to obtain a polymer. The polymer was then filtered and dried to obtain polyacrylonitrile powder. The polyacrylonitrile powder was then dissolved in dimethylacetamide, heated, and filtered to obtain a polyacrylonitrile solution. The polyacrylonitrile solution contained 27% polyacrylonitrile powder and 73% dimethylacetamide.

[0129] A stabilizer and a color corrector are added to a polyacrylonitrile solution. The stabilizer is citric acid, which accounts for 0.02% of the fiber content. The color corrector is a mixture of blue and purple pigments, with a mass ratio of 1:2. The fiber content of the blue pigment is 0.0025%, and the fiber content of the purple dye is 0.005%. A polyacrylonitrile solution containing the color corrector and stabilizer is obtained.

[0130] (2) Preparation of functional slurry, specifically including:

[0131] Dimethylacetamide was mixed and dispersed with colored pigments and antibacterial agents, and then polyacrylonitrile solution and dispersant were added for further dispersion. The mixture was then ground for 8 hours to obtain a functional slurry.

[0132] In the functional slurry, the colored pigment accounts for 11.6% by mass, representing 2% of the fiber mass. The antibacterial agent is nano-silver ions with a particle size of less than 5 μm. The dispersant is nano-sized titanium dioxide, and the polyacrylonitrile solution is the polyacrylonitrile solution containing color corrector and stabilizer prepared in step (1). In the functional slurry, the antibacterial agent accounts for 4% by mass, and the dispersant accounts for 3.7% by mass.

[0133] (3) Polyacrylonitrile wig fibers are prepared using a wet two-step process, specifically including:

[0134] The functional slurry prepared in step (2) is added to the pre-spinning adhesive supply system by pre-spinning injection and mixed with the polyacrylonitrile solution prepared in step (1) to form a spinning adhesive solution. The solution is then sprayed out through a spinneret for spinning, formed in a coagulation bath, washed with water, stretched, oiled, dried, and collected to obtain polyacrylonitrile wig fibers.

[0135] The spinneret has round holes with a diameter of 0.22 mm and 9000 holes. The designed fiber fineness is 48D and the total fineness is 130KTEX.

[0136] The coagulation bath was dimethylacetamide with a concentration of 51%; the coagulation bath temperature was 40℃; the draw ratio was 4.5 times; and the setting pressure was 300 kPa.

[0137] The oiling agent selected for the oiling process is a compound of high-carbon fatty alcohol polyoxyethylene ether, octadecylamine acetate, and water, wherein the mass percentage of high-carbon fatty alcohol polyoxyethylene ether is 40%, the mass percentage of fatty amines is 30%, and the mass percentage of water is 30%. The oiling agent has a pH of 4.0 and a solid content of 70%; the oiling tank temperature is 60℃; and the amount of oiling agent used is 0.4% of the fiber mass.

[0138] Example 4: Preparation of colored antibacterial fibers

[0139] (1) Preparation of a polyacrylonitrile solution containing color corrector and stabilizer, specifically including:

[0140] Acrylonitrile (91.5%) and vinyl acetate (8.5%) were subjected to an aqueous suspension polymerization reaction at a controlled temperature of 61°C and pH of 3 to obtain a polymer. The polymer was then filtered and dried to obtain polyacrylonitrile powder. The polyacrylonitrile powder was then dissolved in dimethylacetamide, heated, and filtered to obtain a polyacrylonitrile solution. The polyacrylonitrile solution contained 24% polyacrylonitrile powder and 76% dimethylacetamide.

[0141] A stabilizer and a color corrector are added to a polyacrylonitrile solution. The stabilizer is acetic acid, and the fiber content is 0.035%. The color corrector is a mixture of blue and purple pigments, with a mass ratio of 1:1. The fiber content of the blue pigment is 0.0045%, and the fiber content of the purple dye is 0.0045%. A polyacrylonitrile solution containing the color corrector and stabilizer is obtained.

[0142] (2) Preparation of functional slurry, specifically including:

[0143] Dimethylacetamide was mixed and dispersed with a colored pigment (orange) and an antibacterial agent, and then polyacrylonitrile solution and dispersant were added for further dispersion. The mixture was then ground for 7 hours to obtain a functional slurry.

[0144] In the functional slurry, the colored pigment (orange) accounts for 8% by mass, representing 1.3% of the fiber mass. The antibacterial agent is nano-silver ions with a particle size of less than 5 μm. The dispersant is nano-sized titanium dioxide, and the polyacrylonitrile solution is the polyacrylonitrile solution containing color corrector and stabilizer prepared in step (1). In the functional slurry, the antibacterial agent accounts for 4% by mass, and the dispersant accounts for 3.7% by mass.

[0145] (3) Polyacrylonitrile wig fibers are prepared using a wet two-step process, specifically including:

[0146] The functional slurry prepared in step (2) is added to the pre-spinning adhesive supply system by pre-spinning injection and mixed with the polyacrylonitrile solution prepared in step (1) to form a spinning adhesive solution. The solution is then sprayed out through a spinneret for spinning, formed in a coagulation bath, washed with water, stretched, oiled, dried, and collected to obtain polyacrylonitrile wig fibers.

[0147] The spinneret has flat orifices with an aspect ratio of 4.5:1 and 6500 orifices. The designed fiber fineness is 48D and the total fineness is 130KTEX.

[0148] The coagulation bath was dimethylacetamide with a concentration of 51%; the coagulation bath temperature was 40℃; the draw ratio was 4.5 times; and the setting pressure was 300 kPa.

[0149] The oiling agent selected for the oiling process is a compound of fatty acid polyoxyethylene ester, alkyl dimethyl benzyl ammonium chloride, and water, wherein the mass percentage of fatty acid polyoxyethylene ester is 45%, the mass percentage of fatty alcohol is 25%, and the mass percentage of water is 30%. The oiling agent has a pH of 4.5 and a solid content of 72%; the oiling tank temperature is 65℃; and the oiling agent dosage is 0.45% of the fiber mass.

[0150] Comparative Example 1

[0151] The only difference between this comparative example and Example 1 is that no color corrector was added.

[0152] Comparative Example 2

[0153] The only difference between this comparative example and Example 1 is that no stabilizer was added.

[0154] Comparative Example 3

[0155] The only difference between this comparative example and Example 1 is that no dispersant was added.

[0156] Comparative Example 4

[0157] The only difference between this comparative example and Example 1 is that the diameter of the spinneret holes on the spinneret plate is 0.3 mm.

[0158] The fibers prepared in Examples 1-4 and Comparative Examples 1-4 were subjected to performance testing, and the results are shown in the table below.

[0159] Table 1

[0160]

[0161] Results analysis:

[0162] Compared to the comparative examples, the fibers prepared in Examples 1-4 of this invention have higher breaking strength and elongation at break, exhibiting excellent mechanical properties. Specifically, the spinnerets in Examples 1 and 3 are round, while those in Examples 2 and 4 are flat. Fibers prepared with flat spinnerets have lower strength than those prepared with round spinnerets.

[0163] Compared with Example 1, no color corrector was added in Comparative Example 1, and the whiteness of the fibers decreased significantly.

[0164] Compared with Example 1, no stabilizer was added in Comparative Example 2, and the fiber's breaking strength, breaking elongation, and boiling water shrinkage all decreased.

[0165] Compared with Example 1, no dispersant was added in Comparative Example 3, and the fiber's breaking strength, breaking elongation, and boiling water shrinkage all decreased significantly.

[0166] Compared with Example 1, in Comparative Example 4, the diameter of the spinneret orifice was too large, which also affected the performance of the fiber, resulting in a significant decrease in the fiber's breaking strength, breaking elongation, and boiling water shrinkage.

[0167] Experimental Example 1

[0168] This experimental example uses the method of Example 1, the difference being the composition of the color corrector. The ratio of the color corrector and the results of the prepared fiber properties are shown in the table below.

[0169] Table 2

[0170] Mass ratio of blue pigment to purple pigment Blue pigment fiber percentage Purple pigment fiber percentage Whiteness Hue 1:0.5 0.007 0.0035 42 Blue light 1：1 0.0035 0.0035 46 Yellowish light 1：1.5 0.0035 0.0053 57 White 1：2 0.0035 0.007 48 bluish light 1:3 0.0035 0.0105 40 Blue light

[0171] Results analysis:

[0172] In this invention, the addition of a color corrector increases the sensory whiteness of the fiber, preventing it from yellowing. The color corrector absorbs yellow light, thus reducing the yellow tint and increasing the whiteness of the fiber. By controlling the mass ratio of blue to purple pigment within the range of 1:1-2, the whiteness of the fiber can be improved. The optimal ratio of blue to purple pigment in the color corrector is 1:1.5, resulting in the best hue. This also improves the consistency between the fiber color and the color chart during the preparation of colored fibers, avoiding color deviation and ensuring that the product color meets customer requirements.

[0173] Experimental Example 2

[0174] This experimental example uses the method of Example 1, the difference being that the spinneret used has flat spinneret holes and a different aspect ratio. The results of the prepared fiber properties are shown in the table below.

[0175] Table 3

[0176]

[0177]

[0178] Results analysis:

[0179] This invention employs a spinneret with flat spinneret orifices and controls the aspect ratio of each orifice within the range of 3-5:1 to produce wig fibers with an elliptical cross-section resembling animal hair. The fibers are fluffy and have a smooth feel. The effect is even better when the aspect ratio of each orifice is 4:1, resulting in a smooth feel, good dispersion, good fluffiness, and a texture similar to human hair, offering high realism and better meeting the needs of individualized users.

[0180] Experimental Example 3

[0181] This experimental example uses the method of Example 1, the difference being the use of different oiling agents. The composition of the oiling agents and the results of the prepared fiber properties are shown in the table below.

[0182] Table 4

[0183]

[0184] Results analysis:

[0185] In the table, resistivity represents the antistatic properties of the fiber. The higher the resistivity, the easier it is to generate static electricity, and the worse the antistatic properties of the fiber.

[0186] As can be seen from the results in the table above, compared with other types of oiling agents, the present invention uses a compound of nonionic and cationic surfactants as an oiling agent, resulting in fibers that are softer, smoother, more dispersible, have better antistatic properties, and are closer to real human hair.

[0187] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing polyacrylonitrile wig fibers, characterized in that, include: (1) Prepare a polyacrylonitrile solution containing color corrector and stabilizer; (2) After mixing and dispersing dimethylacetamide with functional additives, polyacrylonitrile solution and dispersant are added for further dispersion to obtain functional slurry; (3) Mix the polyacrylonitrile solution in (1) with the functional slurry in (2) to obtain the spinning solution, which is then spun through a spinneret to obtain polyacrylonitrile wig fibers.

2. The preparation method according to claim 1, characterized in that, In step (1), the color corrector is selected from one or both of blue and purple pigments; Preferably, the colorant is a mixture of blue and purple pigments; Preferably, the mass ratio of blue pigment to purple pigment in the mixture is 1:1.5; Preferably, the fiber content of blue pigment is 0.0025%-0.0045%, and the fiber content of purple dye is 0.0045%-0.0065%.

3. The preparation method according to claim 1 or 2, characterized in that, In step (1), the stabilizer is selected from one or more of oxalic acid, citric acid, and acetic acid; Preferably, the stabilizer is oxalic acid; Preferably, the fiber content of the stabilizer is 0.02-0.04%, more preferably 0.025-0.035%.

4. The preparation method according to any one of claims 1-3, characterized in that, In step (1), acrylonitrile and vinyl acetate undergo an aqueous suspension polymerization reaction to obtain a polymer, which is then filtered and dried to obtain polyacrylonitrile powder; then the polyacrylonitrile powder is dissolved in dimethylacetamide, heated and filtered to obtain a polyacrylonitrile solution; Preferably, the mass concentration of acrylonitrile is 91.5-92%, and the mass concentration of vinyl acetate is 8-8.5%. Preferably, the temperature of the aqueous suspension polymerization reaction is 59–61°C, and the pH is 2.5–3.5; Preferably, when preparing the polyacrylonitrile solution, the mass percentage of polyacrylonitrile powder is 23-27%, and the mass percentage of dimethylacetamide is 73-77%.

5. The preparation method according to any one of claims 1-4, characterized in that, In step (2), the functional additives include at least one of colored pigments, antibacterial agents, flame retardants, antistatic agents, and animal proteins; Preferably, the functional additive is a colored pigment, or an antibacterial agent, or a colored pigment and an antibacterial agent; Preferably, the functional slurry contains 6.7%-11.6% by mass of colored pigments; Preferably, the colored pigment accounts for 1-2% of the fiber by mass; Preferably, the colored pigment is selected from organic pigments or inorganic salts; Preferably, the colored pigment is selected from quinacridones, phthalocyanines, and anthraquinones; Preferably, the functional slurry contains 3.8-6.2% by mass of antibacterial agent; Preferably, the antibacterial agent accounts for 0.6-1.0% of the fiber by mass. Preferably, the antibacterial agent includes organic antibacterial agents and inorganic antibacterial agents; Preferably, the organic antibacterial agent is selected from at least one of phenols, aldehydes, quaternary ammonium salts, bisphenols, thiols, esters, and chlorine dioxide; the organic antibacterial agent is soluble in dimethylacetamide; Preferably, the inorganic antibacterial agent is selected from at least one of silver ion, copper ion, and zinc ion antibacterial agents; Preferably, the inorganic antibacterial agent is at the nanoscale, with a particle size of less than 5 μm.

6. The preparation method according to any one of claims 1-5, characterized in that, In step (2), the mass percentage of dispersant in the functional slurry is 1.2%-3.7%; Preferably, the dispersant accounts for 0.2-0.6% of the fiber by mass; Preferably, the dispersant includes at least one of a titanium-containing compound and a silicon-containing compound; Preferably, the dispersant includes one or more of nano-sized titanium dioxide, nano-sized silicon dioxide, and nano-sized silicon monoxide.

7. The preparation method according to any one of claims 1-6, characterized in that, In step (3), the spinneret has circular spinneret holes, with 8,000-10,000 holes and a diameter of 0.15-0.22 mm for each hole. Preferably, the spinneret has 9,000 holes, and the diameter of each hole is 0.2 mm. Alternatively, in step (3), the spinneret holes are flat, with a length-to-width ratio of 3-5:1; preferably, the length-to-width ratio of a single hole is 4:1; preferably, the number of holes is 5000-7000; more preferably, the number of holes is 6000.

8. The preparation method according to any one of claims 1-7, characterized in that, After spinning, the process includes an oiling step. The oiling agent used is a mixture of nonionic surfactant, cationic surfactant and water. The mass percentage of nonionic surfactant is 40-50%, the mass percentage of cationic surfactant is 20-30%, and the mass percentage of water is 25-35%. Preferably, in the compound, the mass percentage of nonionic surfactant is 45%, the mass percentage of cationic surfactant is 25%, and the mass percentage of water is 30%. Preferably, the nonionic surfactant is selected from one or more of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyol polyoxyethylene ether fatty acid ester, alkylolamide, polyol monofatty acid ester, glycerol fatty acid ester, alkylphenol polyoxyethylene ether, lauramide monoethanolamine, and glyceryl monolaurate. Preferably, the nonionic surfactant is selected from one or more of alkylphenol polyoxyethylene ether, higher carbon fatty alcohol polyoxyethylene ether, and fatty acid polyoxyethylene ester; Preferably, the cationic surfactant is selected from one or more of amine salts, quaternary ammonium salts, and fatty alcohols; Preferably, the amine salts include primary amine salts, secondary amine salts, and tertiary amine salt surfactants; Preferably, the quaternary ammonium salts include alkyl quaternary ammonium salts; Preferably, the alkyl quaternary ammonium salt is selected from one or more of alkyl dimethyl benzyl ammonium chloride and alkyl dimethyl hydroxyethyl ammonium chloride; Preferably, the pH of the oil is 3.5-5.5; Preferably, the solid content of the oil is 70-74%; Preferably, the oiling agent accounts for 0.4-0.5% of the fiber mass. Preferably, in the oiling step, the temperature of the oiling tank is 60-70℃.

9. A polyacrylonitrile wig fiber obtained by the preparation method according to any one of claims 1-8; Preferably, the polyacrylonitrile wig fiber has a fineness of 48-52 dtex, a breaking strength of 1.5-2.5 CN / dtex, a breaking elongation of 30-40%, a boiling water shrinkage rate of <2%, an oil content of 0.4%, and a fiber whiteness of 50-60.

10. A preparation method according to any one of claims 1-8 or the use of polyacrylonitrile wig fibers according to claim 9 in wig products.

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