Multi-stage dyeing method for artificial hair

Abstract

To provide a multi-stage dyeing method that minimizes color transfer to areas other than those being dyed, when dyeing artificial hair using a general multi-stage dyeing method. [Solution] A multi-step dyeing method for artificial hair, comprising covering a portion of artificial hair made of synthetic fibers, bringing the uncovered exposed portion of the partially covered artificial hair into contact with a dyeing solution, maintaining the dyeing solution at a temperature of 90°C or higher in that state, and removing the dyeing solution and the covering from the artificial hair, wherein the viscosity of the dyeing solution is 20 cp or higher.

Description

Technical Field

[0001] The present invention relates to a multi-stage dyeing method for artificial hair, and particularly to a multi-stage dyeing method for artificial hair made of synthetic fibers.

Background Art

[0002] Hair materials multi-stage dyed with partially different color tones and shades at the root and tip are excellent in fashionability and useful as raw materials for making wigs and headdresses. The multi-stage dyed hair material can be produced, for example, by covering the non-dyed part of the hair, exposing the part to be dyed, and immersing the hair in this state in an aqueous solution of a dyeing agent for dyeing.

[0003] Patent Document 1 describes a method for dyeing a hair material, in which a coloring paste is applied to a predetermined part of the hair material, and after semi-drying, a steam supply member and an evaporation adjustment member composed of a net member and a water-containing member are wound around and heated to penetrate and fix the coloring paste inside the hair material. As a result, it becomes possible to simply and accurately impart different colors and color tones to an arbitrary position of a single hair material, and color separation and camouflage dyeing at a plurality of locations can also be easily performed.

[0004] In recent years, various artificial hair fiber materials (for example, modacrylic fibers, polyvinyl chloride fibers, polyester fibers, etc.) have been increasingly used as hair materials for headdresses. Among the various fiber materials for artificial hair, the fiber material for artificial hair using polyester fibers is preferably used because it has better ironing setting properties due to its higher heat resistance compared to the fiber materials for artificial hair using modacrylic fibers or polyvinyl chloride fibers.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The dyeing method described in Patent Document 1 requires special materials, components, and complex work processes. Furthermore, when applied to artificial hair made of synthetic fibers, the coloring agent does not penetrate and fix sufficiently, resulting in insufficient dyeing. In addition, common multi-stage dyeing methods used industrially have the problem of color transfer occurring to areas other than those being dyed when applied to artificial hair made of synthetic fibers. This color transfer creates bleeding at the ends of the dyed areas. Therefore, these conventional multi-stage dyeing methods have the problem of degrading the appearance quality of multi-stage dyed hair material made of synthetic fibers.

[0007] The present invention solves the aforementioned problems and aims to provide a multi-step dyeing method that can suppress color transfer to areas other than the dyed portion when dyeing artificial hair made of synthetic fibers using a general multi-step dyeing method. [Means for solving the problem]

[0008] The present invention provides the following embodiments. [1] To cover a portion of artificial hair made of synthetic fibers, The exposed, uncovered portion of the partially covered artificial hair is brought into contact with the dye solution. In that state, the staining solution is maintained at a temperature of 90°C or higher, preferably 90-99°C, more preferably 98-99°C, and A multi-step dyeing method for artificial hair, comprising removing the dye solution and coating from the artificial hair, A multi-step dyeing method for artificial hair, wherein the viscosity of the dyeing solution is 20 cp or more, preferably 20 to 40 cp, and more preferably 29 to 33 cp.

[0009] [2] The synthetic fiber comprises polyester fiber, and the multi-step dyeing method for the artificial hair of [1].

[0010] [3] The dyeing solution comprises a water-soluble polymer as a thickening agent, and is a multi-step dyeing method for artificial hair according to [1] or [2].

[0011] [4] The water-soluble polymer has a weight-average molecular weight of 100,000 to 5,000,000, preferably 300,000 to 3,000,000, more preferably 500,000 to 1,000,000. A multi-step dyeing method for artificial hair according to [3].

[0012] [5] The water-soluble polymer is sodium polyacrylate, a multi-step dyeing method for artificial hair according to [3] or [4].

[0013] [6] The dyeing solution is an aqueous dyeing solution containing water as a solvent, a multi-step dyeing method for artificial hair according to any of [1] to [5].

[0014] [7] A multi-step dyeing method for artificial hair according to any of [1] to [6], wherein the dyeing solution comprises a disperse dye.

[0015] [8] A multi-step dyeing method for artificial hair according to any of [1] to [7], wherein the artificial hair, which is partially covered, is immersed in a dyeing solution so that the exposed portion comes into contact with the dyeing solution.

[0016] [9] The artificial hair made of synthetic fibers is a component of a head ornament, and a multi-step dyeing method for the artificial hair according to any of [1] to [8].

[0017]

[10] The head ornament includes hair extensions, hairpieces and wigs, [9] a multi-step dyeing method for artificial hair. [Effects of the Invention]

[0018] According to the multi-stage dyeing method of the present invention, even when dyeing artificial hair made of synthetic fibers using a general multi-stage dyeing method, color transfer to areas other than the dyed portion is suppressed, bleeding is not formed at the dyed ends, and the appearance quality of the multi-stage dyed hair material made of synthetic fibers can be sufficiently improved. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic diagram showing the dyeing state of the hair material after partial dyeing in the example. [Figure 2] This is a schematic diagram showing the relationship between characteristic values ​​related to the dyeing state of wool material after partial dyeing.

Best Mode for Carrying Out the Invention

[0020] Hereinafter, an embodiment of the present invention will be described in detail. However, the scope of the present invention is not limited to the embodiment described here, and various modifications can be made without departing from the spirit of the present invention. Also, when a plurality of upper limit values and lower limit values are described for specific parameters, any upper limit value and lower limit value can be combined to form a suitable numerical range.

[0021] The multi-stage dyeing method of artificial hair of the present invention includes covering a part of artificial hair made of synthetic fiber. Synthetic fiber refers to a fiber manufactured from a polymer material artificially made by polymerizing a low molecular compound by a chemical reaction. The fiber generally refers to a staple fiber. Synthetic fiber is a material distinguishable from human hair, which is a natural fiber.

[0022] In the multi-stage dyeing method of artificial hair of the present invention, the synthetic fiber preferably includes polyester fiber. In a preferred form, the synthetic fiber consists only of polyester fiber. The polyester fiber can be obtained by melt spinning a polyester resin composition containing a polyester resin, a polyphenylene ether resin, and, if necessary, a flame retardant, a flame retardant aid, a light stabilizer, a heat stabilizer, etc.

[0023] The polyester resin mentioned above includes at least one polyester selected from the group consisting of polyalkylene terephthalate, copolymer polyester mainly composed of polyalkylene terephthalate, and resin components obtained by polymer alloying these with other resin components. More specifically, examples include polyalkylene terephthalate such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate, copolymer polyester mainly composed of the polyalkylene terephthalate and containing a small amount of copolymer component, and resin components obtained by polymer alloying the polyalkylene terephthalate with polyethylene naphthalate, polyarylate, polycarbonate, etc.

[0024] Coating refers to covering artificial hair with a sheet-like or film-like material to prevent contact with the external environment, essentially masking it. Coating the artificial hair prevents the coated portion from being dyed. The coating material should be one that can block dyes. Dyeing bags and similar materials are commercially available as coating materials. The coating material is preferably heat-resistant, and metal foils such as aluminum foil may be used.

[0025] In the multi-step dyeing method for artificial hair of the present invention, the uncovered exposed portion of the partially covered artificial hair is brought into contact with the dyeing solution. As a result, the exposed portion of the artificial hair is dyed.

[0026] The dyeing solution used in this invention effectively utilizes all the dyes that have been conventionally applied to dyeing synthetic fibers. For example, cationic dyes, basic dyes, and disperse dyes can be suitably used for modacrylic fibers, acidic dyes and disperse dyes for nylon fibers, and disperse dyes for polyester fibers.

[0027] The dyeing solution is an aqueous dyeing solution containing water as a solvent. Similar to dyeing solutions used in ordinary dyeing, in addition to dyes and water, dye accelerators such as color enhancers, dye slowing agents, dye leveling agents, pH adjusters, wetting agents, and dye dissolving aids may be added as needed.

[0028] The staining solution preferably contains a thickening agent. This makes it easier to adjust the viscosity of the staining solution to a range in which the aforementioned color transfer is suppressed. The thickening agent that can be used in the staining solution may be a water-soluble polymer.

[0029] Examples of water-soluble polymers that can be used as thickeners include acrylic polymers such as polyacrylates, sodium alginate, gum arabic, and cellulose derivatives such as sodium salts of methylcellulose or carboxymethylcellulose. Among these water-soluble polymers, sodium polyacrylate is preferred.

[0030] The weight-average molecular weight (Mw) of the water-soluble polymer is 100,000 to 5,000,000, preferably 300,000 to 3,000,000, and more preferably 500,000 to 1,000,000 in one form. If the Mw of the water-soluble polymer is less than 100,000, the thickening effect may be insufficient, and if it exceeds 5,000,000, the solubility in the staining solution may decrease.

[0031] When dyeing the exposed portion of artificial hair, the partially covered artificial hair is immersed in the dyeing solution, bringing the portion to be dyed into contact with the dyeing solution. The dyeing solution is then maintained at a temperature of 90°C or higher. Maintaining the temperature of the dyeing solution at 90°C or higher allows for sufficient dyeing of the artificial hair made of synthetic fibers. The temperature of the dyeing solution is preferably adjusted to 90°C or higher and less than 100°C, more preferably to 98-99°C. The dyeing time is adjusted as appropriate to obtain the desired color after dyeing, but in one embodiment, it is adjusted to 15 minutes to 1.5 hours, preferably 20 minutes to 1 hour, more preferably to 30-45 minutes.

[0032] Furthermore, during dyeing, the viscosity of the dyeing solution is adjusted to 20 cp or higher. Maintaining a viscosity of 20 cp or higher in the dyeing solution during the dyeing of artificial hair can suppress the aforementioned color transfer. The viscosity of the dyeing solution is preferably adjusted to 20-40 cp, more preferably to 29-33 cp. If the viscosity of the dyeing solution exceeds 40 cp, the desired color may not be obtained after dyeing. The viscosity of the dyeing solution can be measured by the method described in the examples.

[0033] After the dyeing process is complete, the dye solution and coating are removed from the artificial hair. As a result, the coated portion retains its original color, while the exposed portion is dyed to the desired color, creating artificial hair with gradually different shades.

[0034] In one embodiment, the artificial hair used for covering may be a synthetic fiber material that is not yet a component of a head ornament. In another embodiment, the artificial hair used for covering may be a synthetic fiber that has been processed into a component of a head ornament. Specific examples of head ornaments mentioned here include hair extensions, hairpieces, and wigs. [Examples]

[0035] The present invention will be further described by the following examples, but the present invention is not limited thereto.

[0036] <Examples> The following materials were prepared.

[0037] [Table 1]

[0038] 10g of 20cm long hair material was placed side by side, folded in half in the middle, and tied to create a 10cm long folded hair bundle. In the folded hair bundle, the folded end becomes the root, and the unfolded end becomes the tip. The folded hair bundle was placed into a mask bag from the tip end, leaving 4cm of the root end exposed, and the opening of the mask bag was tightly tied with string. The entire mask bag, from the sealed part, was then covered with aluminum foil.

[0039] Water, dye, color enhancer, and sodium polyacrylate were mixed in predetermined amounts, heated in a constant-temperature water bath (Yamato Scientific Co., Ltd. "Water Bath BM100" (product name)), and stirred with a stirrer (Shinto Scientific Co., Ltd. "High-Power General-Purpose Stirrer BLh1200" (product name)) to prepare a dyeing solution, and the viscosity of each dyeing solution was measured. The viscosity measurement conditions were as follows:

[0040] [Table 2]

[0041] The dye solution was heated to 90°C. The folded hair bundles, fitted with mask bags, were immersed in the dye solution, and dyeing was performed for 30 minutes while maintaining the dye solution temperature above 90°C. After dyeing, the hair bundles were removed from the dye solution, the mask bags were removed, the folds were undone, the dye solution was rinsed off, the shape was adjusted, and the hair was allowed to air dry.

[0042] The obtained partially stained hair material was stained in a length of approximately 4 cm from the center toward both ends, the portion that was in the mask bag from both ends remained unstained, and a bleeding-like color transfer was observed at the boundary between the two. Figure 1 is a schematic diagram showing the staining state of the partially stained hair material in the example.

[0043] The partially stained and unstained hair samples were observed side by side, and the length from the tip to the point where the coloring began was defined as the area without bleeding (cm). In addition, the length from the partially stained end 4 cm from the center of the stained hair bundle to the end of the hair bundle was measured and defined as the length from the partially stained end to the end of the hair sample (cm).

[0044] Then, the percentage (%) of the area without bleeding (cm) relative to the length (cm) from the partially dyed end to the end of the hair material after partial dyeing was calculated. Figure 2 is a schematic diagram showing the relationship between characteristic values ​​related to the dyeing state of the hair material after partial dyeing.

[0045] The average of the percentage of non-bleeding areas obtained on both sides of the wool sample was defined as the percentage of non-bleeding areas obtained in one partial staining. This partial staining was performed three times, and the average of the percentage of non-bleeding areas for each was calculated and used as the measured value. The results are shown in Table 3.

[0046] [Table 3]

[0047] As the viscosity of the dyeing solution increased, the area without bleeding also increased. Furthermore, when the area without bleeding was large, it was confirmed that the hair material after partial dyeing showed less noticeable bleeding at the boundary between the dyed and undyed areas, resulting in high visual quality.

[0048] <Reference example> Dyes, color enhancers, and sodium polyacrylate (molecular weight Mw: 5.1 × 10) 2 A staining solution was prepared in the same manner as in the examples, except that the following ingredients were mixed in predetermined amounts, and the viscosity was measured. The results are shown in Table 4.

[0049] [Table 4]

[0050] It was shown that when the molecular weight of sodium polyacrylate added to the staining solution is low, the viscosity-increasing effect of the staining solution is weakened.

Claims

1. To cover a portion of artificial hair made of synthetic fibers, The exposed, uncovered portion of the partially covered artificial hair is brought into contact with the dye solution. Maintain the staining solution at a temperature of 90°C or higher in that state, and A multi-step dyeing method for artificial hair, comprising removing the dye solution and coating from the artificial hair, The aforementioned synthetic fiber includes polyester fiber, The artificial hair, which is partially covered, is immersed in a dyeing solution, thereby bringing the exposed portion into contact with the dyeing solution. The aforementioned staining solution is an aqueous staining solution containing water as a solvent. The aforementioned dyeing solution comprises a water-soluble polymer as a thickening agent, a disperse dye, and a dye accelerator. A multi-step dyeing method for artificial hair, wherein the viscosity of the dyeing solution during dyeing of the artificial hair is 29 to 33.3 cp.

2. The multi-step dyeing method for artificial hair according to claim 1, wherein the water-soluble polymer has a weight-average molecular weight of 100,000 to 5,000,000.

3. The multi-step dyeing method for artificial hair according to Claim 1, wherein the water-soluble polymer has a weight-average molecular weight of 500,000 to 1,000,000.

4. The multi-step dyeing method for artificial hair according to claim 1, wherein the water-soluble polymer is a polyacrylate salt.

5. The multi-step dyeing method for artificial hair according to claim 4, wherein the polyacrylate salt is sodium polyacrylate.

6. The multi-step dyeing method for artificial hair according to claim 1, wherein the synthetic fiber consists solely of polyester fiber.

7. The multi-stage dyeing method for artificial hair according to Claim 1, wherein the dyeing solution is maintained at 90°C or higher and less than 100°C during dyeing.

8. The artificial hair made of synthetic fibers is a component of a head ornament, according to any one of claims 1 to 7, a multi-step dyeing method for artificial hair.

9. The multi-step dyeing method for artificial hair according to claim 8, wherein the head ornament includes hair extensions, hairpieces, and wigs.

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