Method for treating hair

Abstract

To provide a technique capable of treating hair by a method different from conventional ones.SOLUTION: A method for treating hair includes: a forming step of forming a plurality of grooves having a depth of 1 μm or less on hair; and a coating step of coating hair treatment liquid to the hair on which a plurality of grooves are formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to methods of treating hair. [Background technology]

[0002] In recent years, the proportion of men visiting beauty salons has increased, and the use of hair coloring not only for dyeing gray hair but also for fashion purposes has become more prevalent. Generally, oxidation-type hair dyes that dye hair through an oxidation reaction between an alkaline agent contained in a first agent and an oxidizing agent contained in a second agent are known as hair coloring agents (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 137877 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional dyeing methods use chemicals that are highly damaging to hair and skin, which can potentially damage the hair and skin. For this reason, there has been a demand for other methods for dyeing hair. Furthermore, these issues are not limited to hair dyeing, but are common to all hair treatments, including bleaching, bleaching, hair growth, hair restoration, treatment, and perms. Therefore, an object of the present disclosure is to provide a technology that can treat hair in a different way than conventional methods. [Means for solving the problem]

[0005] The present invention can be realized as the following aspects.

[0006] (1) According to one aspect of the present disclosure, there is provided a method for treating hair. This method includes a forming step of forming a plurality of grooves having a depth of 1 μm or less in the hair, and an application step of applying a hair treatment solution to the hair with the plurality of grooves formed therein. This method allows hair to be treated in a manner different from conventional methods.

[0007] (2) The method according to (1) above may further include a bending step of bending the hair with a radius of curvature of 10 μm or more and 500 μm or less after the forming step. This method can further improve the durability of the effect of the hair treatment solution.

[0008] (3) The method according to (1) or (2) above may further include a heat treatment step of heat treating the hair after the application step so that the temperature of the hair is 40° C. or more and 150° C. or less. This form of the method can enhance the retention effect of the hair treatment solution, thereby further improving the durability of the effect of the hair treatment solution.

[0009] (4) In the method according to any one of (1) to (3), the grooves may have a depth of 300 nm to 500 nm. This method can further improve the durability of the effect of the hair treatment liquid.

[0010] (5) In the method according to any one of (1) to (4) above, the forming step may involve contacting the hair with water containing an abrasive. According to this form of the method, grooves are formed in the hair by contacting the hair with water containing an abrasive, which can prevent the grooves formed in the hair from becoming uneven.

[0011] (6) In the method according to any one of (1) to (5) above, the forming step may involve massaging a composition containing an abrasive into the hair. According to this form of the method, grooves are formed in the hair by massaging the composition containing an abrasive into the hair, which can prevent the grooves formed in the hair from becoming uneven.

[0012] (7) In the method according to any one of (1) to (6) above, in the forming step, a blade having a cutting edge of 10 μm or less may be applied to the hair. According to this form of the method, grooves can be formed in the hair by applying a blade having a cutting edge of 10 μm or less to the hair.

[0013] (8) In the method according to any one of (1) to (7) above, the forming step may involve rubbing the hair with a file of #1000 or larger. According to this form of the method, grooves can be formed in the hair by rubbing the hair with a file of #1000 or larger.

[0014] The present invention can be realized in various forms, such as a method for dyeing hair, a method for bleaching hair, a method for destaining hair, a hair growth method, a hair restoration method, and the like. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a process diagram showing a method for treating hair. [Figure 2] FIG. 6 is a process diagram showing a hair treatment method according to a second embodiment. [Figure 3] FIG. 1 is a perspective view showing an overview of a hair bending tool. [Figure 4] FIG. 10 is a perspective view showing a schematic configuration of an instrument according to another embodiment. [Figure 5] FIG. 1 is an explanatory diagram showing a device used to bend hair. [Figure 6] FIG. 1 is an explanatory diagram showing the results of Test 1. [Figure 7] FIG. 10 is an explanatory diagram showing the results of Test 2. [Figure 8] FIG. 1 is an explanatory diagram showing the staining results in Test 3. [Figure 9] 10 is an image showing the staining results in Test 3. [Figure 10] FIG. 10 is an explanatory diagram showing the measurement results of the root mean square height and the maximum valley depth in Test 4. [Figure 11] FIG. 1 is a perspective view showing a schematic configuration of the device used in Tests 5 to 7. [Figure 12] FIG. 10 is an explanatory diagram showing the measurement results of surface roughness in Test 5. [Figure 13] FIG. 10 is an explanatory diagram showing the measurement results of surface roughness in Test 6. [Figure 14] FIG. 10 is an explanatory diagram showing the results of Test 7. [Figure 15] FIG. 10 is an explanatory diagram showing the results of Test 8. DETAILED DESCRIPTION OF THE INVENTION

[0016] A. First embodiment FIG. 1 is a process diagram showing a hair treatment method according to one embodiment of the present disclosure. The hair treatment method includes a forming step (P110) of forming multiple grooves in the hair with a depth of 1 μm or less, and an application step (P120) of applying a hair treatment solution to the hair with the multiple grooves formed therein. The hair in the present disclosure is not particularly limited, but examples thereof include human hair, beard, eyebrows, leg hair, and other body hair; pet hair such as dogs and cats; livestock hair such as horses and sheep; and other animal hair. The hair in the present disclosure also includes wigs and extensions made from human hair and natural fibers made from animal hair. The natural fibers are not particularly limited, but examples thereof include wool, cashmere, alpaca, angora, and the like.

[0017] The size and quantity of the multiple grooves formed in the forming step are not particularly limited, but are preferably formed substantially uniformly in the area where hair is to be treated. The depth of the grooves is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effects of the hair treatment solution, it is preferably 50 nm to 1 μm, more preferably 100 nm to 800 nm, even more preferably 200 nm to 600 nm, even more preferably 300 nm to 500 nm, and particularly preferably 400 nm to 500 nm. The length of the grooves is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effects of the hair treatment solution, it is preferably 10 μm to 100 μm, more preferably 20 μm to 80 μm, and even more preferably 40 μm to 60 μm. The width of the grooves is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effects of the hair treatment solution, it is preferably 1 μm to 20 μm, more preferably 2 μm to 15 μm, and even more preferably 4 μm to 10 μm. In the present disclosure, the depth of a groove means the dimension along the direction from the surface of the hair toward the center, the length of a groove means the dimension along the longitudinal direction of the groove on the surface of the hair, and the width of a groove means the dimension along the lateral direction of the groove on the surface of the hair.

[0018] The forming step is preferably carried out by a method that can prevent the grooves formed in the hair from becoming uneven in the area where the hair is to be treated. The unevenness of the grooves means, for example, unevenness in the formation location, depth, width, length, etc., of multiple grooves. The method that can prevent the grooves formed in the hair from becoming uneven is not particularly limited, but is preferably at least one method selected from the group consisting of the following (Method 1) to (Method 4). Note that each method may be used in combination. (Method 1) Contacting hair with water containing abrasives (Method 2) Rub a composition containing an abrasive into the hair (Method 3) Apply a blade with a cutting edge of 10 μm or less to the hair. (Method 4) Rub the hair with a file of #1000 or larger.

[0019] The abrasives used in Methods 1 and 2 and the abrasives contained in the file used in Method 4 are not particularly limited and include, for example, inorganic particles and organic particles, but inorganic particles are preferred. Inorganic particles include, but are not particularly limited to, alumina, calcium carbide, silicon carbide, titanium oxide, zirconia, diamond, etc. Organic particles include, but are not particularly limited to, polyamide, cellulose, etc. In the present disclosure, the particle size and grain size of the abrasive are specified according to the methods described in Japanese Industrial Standards JIS R 6001-1:2017 and JIS R 6001-2:2017.

[0020] The method of contacting hair with water containing an abrasive (Method 1) is not particularly limited, and examples thereof include rinsing hair with water in which an abrasive is dispersed, immersing hair in water in which an abrasive is dispersed, and pouring water in which an abrasive is dispersed on hair. Method 1 is preferably a method of rinsing hair with water in which an abrasive is dispersed, from the viewpoint of further suppressing unevenness of grooves formed in the hair. In the embodiment in which hair is immersed in water in which an abrasive is dispersed, from the viewpoint of further suppressing unevenness of grooves formed in the hair, it is preferable to immerse hair in running water in which an abrasive is dispersed. The method of contacting hair with water containing an abrasive may be carried out, for example, by shampooing hair with a shampoo and then running the shampoo. Alternatively, the abrasive may be dispersed in the shampoo, and the method may be carried out by shampooing hair with the shampoo. From the viewpoint of economy, the water containing an abrasive is preferably circulated water that is used by being recycled. The water containing an abrasive may further contain an additive. The additives are not particularly limited, but examples thereof include solvents, emulsifiers, dispersants, preservatives, surfactants, thickeners, buffers, fragrances, colorants, and the like.

[0021] The particle size of the abrasive particles in the abrasive-containing water is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid, it is preferably 0.5 μm to 100 μm, more preferably 1.0 μm to 50 μm, even more preferably 1.5 μm to 10 μm, and even more preferably 2 μm to 5 μm. The concentration of the abrasive in the abrasive-containing water ([mass (g) of abrasive] / [total mass (g)]×100(%)) is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid, it is preferably 0.1 mass% to 40 mass%, more preferably 1 mass% to 20 mass%, and even more preferably 5 mass% to 10 mass%. The number ratio of the abrasive in the abrasive-containing water ([number of abrasive particles (pieces)] / [total mass (g)]) is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid, it is preferably 7×10 17 ~3×10 20 Preferably, it is 7 x 10 18 ~1.5×10 20 More preferably, it is 3.5×10 19 ~7×10 19 It is more preferable that the flow rate of the abrasive-containing water is 0.5 mL / sec or more and 100 mL / sec or less, preferably 2 mL / sec or more and 50 mL / sec or less, and more preferably 4 mL / sec or more and 20 mL / sec or less, from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid. The time for which the abrasive-containing water is brought into contact with the hair is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid and preventing the time required for the formation step from becoming excessively long, it is preferably 30 seconds or more and 1 hour or less, more preferably 1 minute or more and 30 minutes or less, and even more preferably 3 minutes or more and 15 minutes or less.

[0022] The method of massaging an abrasive-containing composition into hair (Method 2) is not particularly limited, but examples thereof include massaging hair with an abrasive-containing composition and rubbing the abrasive-containing composition into hair. The abrasive-containing composition is not particularly limited and may be aqueous or oil-based, but is preferably aqueous from the viewpoint of being easily washed off with water. The abrasive-containing composition is not particularly limited, but is preferably in the form of a paste, cream, or gel at 25°C, and more preferably in the form of a paste. The specific composition of the abrasive-containing composition is not particularly limited, but may contain a solvent and a carrier. Examples of the solvent include, but are not limited to, water, alcohol, oil, etc. Examples of the alcohol include, but are not limited to, ethanol, propylene glycol, etc. Examples of the oil include, but are not limited to, olive oil, coconut oil, silicone oil, etc. The abrasive-containing composition may further contain additives. Examples of the additives include, but are not limited to, emulsifiers, dispersants, preservatives, surfactants, thickeners, buffers, fragrances, colorants, etc.

[0023] The particle size of the abrasive particles in the composition containing the abrasive is not particularly limited, but is preferably 0.5 μm to 100 μm, more preferably 2 μm to 50 μm, from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid. The concentration of the abrasive in the composition containing the abrasive ([mass (g) of abrasive] / [total mass (g)]×100(%)) is not particularly limited, but is preferably 0.1 mass% to 40 mass%, more preferably 1 mass% to 20 mass%, and even more preferably 5 mass% to 10 mass%. The number ratio of the abrasive in the composition containing the abrasive ([number of abrasive particles (pieces)] / [total mass (g)]) is not particularly limited, but is preferably 7×10, from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid. 17 ~3×10 20 Preferably, it is 7 x 10 18 ~1.5×10 20More preferably, it is 3.5×10 19 ~7×10 19 It is more preferable that the pressure be 0.1 kPa or more and 100 kPa or less, preferably 1 kPa or more and 50 kPa or less, and more preferably 10 kPa or more and 20 kPa or less, from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid. The time for which the composition containing an abrasive is massaged into the hair is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid and preventing the time required for the formation step from being excessively long, it is preferably 30 seconds or more and 1 hour or less, more preferably 1 minute or more and 30 minutes or less, and even more preferably 3 minutes or more and 15 minutes or less.

[0024] The method of applying a blade having a cutting edge of 10 μm or less to the hair (Method 3) is not particularly limited, but examples thereof include a method of moving a blade having a cutting edge of 10 μm or less relatively in a direction approximately perpendicular to the longitudinal direction of the hair, and a method of combing the hair with a brush equipped with a blade having a cutting edge of 10 μm or less. The dimension of the cutting edge is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment solution, it is preferably 0.1 μm to 10 μm, more preferably 0.5 μm to 10 μm, and even more preferably 1 μm to 5 μm. The material of the blade is not particularly limited, but examples thereof include ceramic, stainless steel, carbon steel, and cemented carbide.

[0025] The method of scrubbing hair with a file of #1000 or greater (Method 4) is not particularly limited, but examples include a method of scrubbing hair with a rotating file of #1000 or greater attached to a router, and a method of combing hair with a brush equipped with a file of #1000 or greater. The grit size of the file is not particularly limited, but from the viewpoint of preventing a decrease in the durability of the effect of the hair treatment liquid, it is preferably #1000 or greater but #100,000, more preferably #2000 or greater but #50,000, and even more preferably #4000 or greater but #10,000.

[0026] 1, a hair treatment liquid is applied to the hair with the grooves formed therein. The hair treatment liquid is not particularly limited, but examples thereof include hair dyes, hair coloring agents, bleaching agents, bleaching agents, hair growth agents, hair restoration agents, treatment agents, and perm agents.

[0027] Hair dyes are not particularly limited, but examples thereof include oxidative hair dyes and non-oxidative hair dyes. Oxidative hair dyes are not particularly limited, but examples thereof include those in which a first agent containing an oxidative dye such as paraphenylenediamine, meta-aminophenol, para-aminophenol, or toluene-2,5-diamine is mixed with a second agent containing hydrogen peroxide. Non-oxidative hair dyes are not particularly limited, but examples thereof include those in which a first agent containing a polyhydric phenol such as tannic acid or pyrogallol is applied to hair, and then a second agent containing ferrous sulfate or the like is applied to hair.

[0028] Hair dyes include, but are not limited to, those containing an acid dye such as Black No. 401 and dyeing hair under acidic conditions, those containing a dye such as Basic Brown 16 and dyeing hair under weakly acidic to weakly alkaline conditions, and those containing colorants such as pigments. Bleaching agents include, but are not limited to, those containing persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, or hydrogen peroxide, which decompose melanin pigments in hair. Decoloring agents include, but are not limited to, those containing persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, and hydrogen peroxide, which decompose pigments remaining in hair. Hair dyes may contain natural pigments. Natural pigments include, but are not limited to, carotenoids, chlorophyll, anthocyanins, and the like. The method of the present disclosure can dye hair that is generally difficult to dye with natural pigments, such as black hair.

[0029] Hair growth agents include, but are not limited to, those containing hair growth ingredients such as adenosine, carpronium chloride, Swertia japonica extract, t-flavanone, pentadecane, vitamin B5 (pantothenyl ethyl ether), and hinokitiol. Hair growth agents include, but are not limited to, those containing hair growth promoting ingredients such as minoxidil. Treatment agents include, but are not limited to, those containing cationic surfactants. Perm agents include, but are not limited to, those using a first agent containing a reducing agent such as thioglycolic acid or cysteine and a second agent containing an oxidizing agent such as bromate or hydrogen peroxide.

[0030] The hair treatment solution may contain other optional ingredients. Examples of other optional ingredients include, but are not limited to, vitamins such as vitamin A, vitamin B2, vitamin B6, vitamin C, and vitamin E; minerals such as zinc, iron, calcium, and potassium; vegetable oils such as shea butter and jojoba oil; surfactants; silicone; amino acids; polypeptides; ceramides; isoflavones; proteins; keratin; cystine; and collagen. The hair treatment solution may be used alone or in combination with two or more different ingredients. The hair treatment solution may be in the form of a cream, emulsion, gel, aerosol, foam, or the like, and may be in the form of a liquid.

[0031] When the forming step is carried out by at least one of the above method 1 and method 2, a step of removing the water or composition containing an abrasive from the hair may be included before the applying step, and a step of drying the hair may be included after the step of removing the water or composition containing an abrasive from the hair.

[0032] The hair treatment method of the first embodiment described above includes a step of forming multiple grooves in the hair with a depth of 1 μm or less, thereby enabling hair treatment in a manner different from conventional methods. While the mechanism behind this is unclear, the following mechanism is presumed. It is believed that by forming multiple nanometer-order minute grooves in the hair, the hair treatment solution penetrates and is retained in these grooves. Therefore, for example, in the case of hair coloring, while conventional hair coloring uses a chemical reaction to dye the hair, the hair treatment method of this embodiment can be said to be a physical method in which multiple minute grooves are formed in the hair, allowing a dye or other agent to penetrate and then trap the agent.

[0033] Unlike the present disclosure, conventional methods of treating hair using chemical agents that cause chemical reactions may cause damage to hair and skin by using chemical agents that are highly damaging to hair and skin. For example, methods that increase the penetration of chemical agents by opening the cuticle with chemicals reduce the amount of 18-methyleicosanoic acid present on the surface of the cuticle, resulting in a loss of hair luster.

[0034] In contrast, the method of the present embodiment includes a step of forming multiple grooves in the hair with a depth of 1 μm or less, thereby enabling hair treatment in a manner different from conventional methods. As a result, the amount of chemicals used in the hair treatment solution that are highly damaging to hair and skin can be reduced, or the use of such chemicals can be avoided. As a result, damage to hair and skin can be suppressed. Furthermore, since the need to open the cuticle using chemicals can be omitted, the reduction of 18-methyleicosanoic acid (18-MEA) on the hair surface can be suppressed. As a result, loss of hair luster can be suppressed. Furthermore, the method of the present embodiment allows the amount of chemicals used in the hair treatment solution that may cause allergies to be reduced, or the use of such chemicals can be avoided, making hair treatment possible for users with chemical allergies.

[0035] Furthermore, according to the method of this embodiment, an increase in the number of steps required for hair treatment can be suppressed, thereby suppressing an increase in the cost required for hair treatment. Furthermore, according to the method of this embodiment, hair can be easily treated, thereby reducing the labor required for hair treatment. As a result, the method can be used not only in beauty salons and barber shops, but also when the recipient treats their own hair, such as in self-hair coloring. Furthermore, according to the method of this embodiment, it can be used not only on human hair but also on animal hair. Furthermore, by repeatedly performing the method of this embodiment, re-coloring can be easily performed, such as bleaching after dyeing and then dyeing again.

[0036] B. Second embodiment FIG. 2 is a process diagram showing a hair treatment method according to a second embodiment. The method of the second embodiment further includes a bending step (P115) after the shaping step (P110) in which the hair is bent with a curvature radius of 10 μm or more and 500 μm or less. The method of the second embodiment also includes a heat treatment step (P130) after the application step (P120) in which the hair is heat-treated to a temperature of 40° C. or more and 150° C. or less. The other steps are the same as those in the method of the first embodiment, and therefore detailed description thereof will be omitted. Note that at least one of the bending step and the heat treatment step may be omitted.

[0037] In the bending step, the hair is bent using a hair bending tool. The hair bending tool is not particularly limited as long as it can bend the hair under the above conditions. An example of the hair bending tool is shown below.

[0038] 3 is a perspective view showing an outline of a hair bending tool. Tool 100 comprises a first member 10 and a second member 20. As will be described later, first member 10 and second member 20 are used in combination so as to face each other.

[0039] The first member 10 has a protrusion 11 and a pair of receiving portions 12. The protrusion 11 extends along a first direction D1. The protrusion 11 protrudes in a second direction D2 perpendicular to the first direction D1. In the present disclosure, "perpendicular" does not necessarily mean intersecting at a 90° angle, but also includes intersecting at an approximately perpendicular angle of 80° to 100°. The protrusion 11 functions to locally bend the hair and apply tension to the hair. In a cross section along the second direction D2, i.e., a cross section perpendicular to the first direction D1, the curvature radius R of the protrusion 11 is formed to be 10 μm or more and 500 μm or less. The curvature radius R of the protrusion 11 is preferably 15 μm or more and 400 μm or less, more preferably 30 μm or more and 300 μm or less, even more preferably 50 μm or more and 250 μm or less, and particularly preferably 80 μm or more and 200 μm or less. By setting the radius of curvature R to be equal to or greater than the lower limit, it is possible to prevent hair breakage and damage to the hair. By setting the radius of curvature R to be equal to or less than the upper limit, it is possible to improve the penetration of the hair treatment solution. The radius of curvature R of the convex portions 11 may be set depending on the type, quality, thickness, etc. of the hair to be treated.

[0040] In the example shown in Fig. 3, the angle θ of the convex portion 11 in the cross section along the second direction D2 is formed to be 5° or more and 90° or less. The angle θ is preferably 5° or more and 90° or less, more preferably 10° or more and 80° or less, and even more preferably 15° or more and 70° or less. By setting the angle θ to be equal to or greater than the above lower limit, it is possible to prevent the hair from being cut or damaged. Furthermore, by setting the angle θ to be equal to or less than the above upper limit, it is possible to prevent the size of the device 100 from becoming excessively large.

[0041] The pair of receiving portions 12 are formed so as to be connected to both ends of the protrusion 11. The pair of receiving portions 12 extend along the first direction D1 and are formed substantially parallel to the protrusion 11. The pair of receiving portions 12 face a pair of support portions 22, which will be described later, when the instrument 100 is in use. In the example shown in FIG. 3, the pair of receiving portions 12 are each formed by a substantially flat surface connected to the protrusion 11, but may have any shape. The pair of receiving portions 12 may be omitted.

[0042] The second member 20 has a connecting portion 21 and a pair of support portions 22. The connecting portion 21 connects the pair of support portions 22 to each other. In the example shown in FIG. 3, the connecting portion 21 is formed to extend along the first direction D1 and faces the protrusion 11 when the device 100 is in use. In the example shown in FIG. 3, the connecting portion 21 is formed by a substantially flat surface, but may have any shape. The connecting portion 21 may have any configuration, such as connecting the pair of support portions 22 to each other at the ends in the first direction D1. Note that the connecting portion 21 may be omitted.

[0043] The pair of support portions 22 extend along the first direction D1 and support hair on both sides of the protrusion 11. The pair of support portions 22 are arranged to sandwich the protrusion 11 when the tool 100 is in use. Therefore, in a cross section taken along the second direction D2, the protrusion 11 is located between the pair of support portions 22. In the example shown in FIG. 3, the pair of support portions 22 are formed so as to be connected to the connecting portions 21, respectively. In the example shown in FIG. 3, the pair of support portions 22 face the pair of receiving portions 12. In the example shown in FIG. 3, the pair of support portions 22 are formed so as to protrude in a direction opposite to the direction in which the protrusion 11 protrudes. The pair of support portions 22 may have any configuration capable of supporting hair on both sides of the protrusion 11, such as a pair of cylindrical members or rubber rollers extending in the first direction D1.

[0044] In the example shown in FIG. 3, the first member 10 has one protrusion 11, but may have a plurality of protrusions 11. In this embodiment, the plurality of protrusions 11 may be formed substantially parallel to one another. Furthermore, in the example shown in FIG. 3, the second member 20 has a pair of support portions 22, but may have a plurality of pairs of support portions 22. In this embodiment, the plurality of pairs of support portions 22 may be formed substantially parallel to one another. The number of pairs of support portions 22 may be set according to the number of protrusions 11.

[0045] The first member 10 and the second member 20 may be formed from any material, such as a resin material or a metal material. Resins are not particularly limited, but examples thereof include polycarbonate and ABS resin. Metals are not particularly limited, but examples thereof include stainless steel, aluminum, and iron. The first member 10 and the second member 20 may each be formed from two or more types of material, and may be formed from the same material or different materials.

[0046] When using the tool 100, i.e., during the bending step, the hair is sandwiched between the first member 10 and the second member 20 so that the longitudinal direction of the hair intersects the first direction D1. At this time, it is preferable to sandwich the hair between the first member 10 and the second member 20 so that the longitudinal direction of the hair intersects the first direction D1 approximately perpendicularly. Then, while bending the hair at an angle of 30° to 120°, the first member 10 and the second member 20 are moved along the longitudinal direction relative to the hair. At this time, the hair is locally bent with a curvature radius of 10 μm to 500 μm, and the bent portion is moved along the longitudinal direction. The bending step may be repeated multiple times to improve the penetration of the hair treatment solution.

[0047] The tension during the bending step is preferably 0.1 MPa or more and 270 MPa or less, more preferably 0.5 MPa or more and 180 MPa or less, even more preferably 5 MPa or more and 160 MPa or less, even more preferably 10 MPa or more and 100 MPa or less, and even more preferably 20 MPa or more and 50 MPa or less. By setting the tension at or above the lower limit, the penetration of the hair treatment solution can be improved. Furthermore, by setting the tension at or below the upper limit, hair breakage and damage to the hair can be suppressed. From the viewpoint of improving the penetration of the hair treatment solution, the tension during the bending step is preferably set to 40% or more of the breaking strength of the hair to be treated, more preferably 80% or more. From the viewpoint of suppressing hair breakage and damage to the hair, the tension during the bending step is preferably set to 95% or less of the breaking strength of the hair to be treated, more preferably 90% or less. The breaking strength can be determined based on the stress-strain curve obtained by performing a simple tensile test on the hair. The tension in the bending process may be set depending on the type, quality, thickness, breaking strength, etc. of the hair to be treated. The tension in the bending process may be adjusted by a weight (not shown) for controlling the load. Furthermore, the tension in the bending process may be controlled by a control device (not shown).

[0048] In the bending step, the hair is preferably bent at an angle of 30° or more and 120° or less. Bending the hair at an angle of 30° or more and 120° or less can enhance the penetration of the hair treatment solution. From the viewpoint of preventing hair breakage and damage to the hair, the bending angle of the hair is more preferably 40° or more, even more preferably 50° or more, and particularly preferably 60° or more. From the viewpoint of enhancing the penetration of the hair treatment solution, the bending angle of the hair is more preferably 110° or less, even more preferably 100° or less, and particularly preferably 90° or less. The bending angle of the hair may be set depending on the type, texture, thickness, etc. of the hair to be treated.

[0049] In the bending step, the speed at which the first member 10 and the second member 20 are moved relative to the hair is preferably 200 mm / min or less, more preferably 150 mm / min or less, even more preferably 100 mm / min or less, even more preferably 80 mm / min or less, and particularly preferably 60 mm / min or less, from the viewpoint of improving the penetration of the hair treatment solution. Furthermore, from the viewpoint of shortening the treatment time, the moving speed is preferably 20 mm / min or more, more preferably 40 mm / min or more, and even more preferably 50 mm / min or more. The moving speed may be set depending on the type, texture, thickness, etc. of the hair to be treated. Furthermore, the moving speed may be controlled by a device including a motor (not shown) for feeding the hair or a speed controller (not shown).

[0050] The bending step may be carried out when the hair temperature is 40°C or higher and 150°C or lower. The method for controlling the hair temperature is not particularly limited, and for example, a hair dryer, a heater (roller ball), a far-infrared accelerator, or the like may be used. From the viewpoint of enhancing the penetration effect of the hair treatment solution, the hair temperature during the bending step is preferably 20°C or higher, more preferably 30°C or higher, and more preferably 40°C or higher. Furthermore, from the viewpoint of suppressing damage to the hair, the hair temperature during the bending step is preferably 120°C or lower, and more preferably 100°C or lower. The hair temperature during the bending step may be set depending on the type, quality, thickness, etc. of the hair to be treated.

[0051] In the second embodiment, the application step may be performed after the bending step or simultaneously with the bending step. By performing the application step simultaneously with the bending step, the penetration effect of the hair treatment solution can be enhanced. Furthermore, by performing the application step simultaneously with the bending step, the hair treatment time can be shortened. When the application step is performed after the bending step, it is preferable to perform the application step promptly after the bending step.

[0052] In the heat treatment step carried out after the application step, the hair is heat-treated so that the hair temperature is between 40°C and 150°C. The heat treatment method is not particularly limited, but for example, a hair dryer, a heater (roller ball), a far-infrared accelerator, or the like may be used. By carrying out the heat treatment step, the retention effect of the hair treatment solution can be enhanced, thereby further improving the durability of the effects of the hair treatment solution. While the mechanism behind this is unclear, the following mechanism is presumed. Specifically, it is presumed that the grooves formed in the hair during the shaping step and the pores of the hair made porous during the bending step shrink due to the heat treatment in the heat treatment step, and the hair treatment solution is fixed inside the grooves and pores.

[0053] The temperature of the hair in the heat treatment step is preferably 50°C or higher, more preferably 60°C or higher, from the viewpoint of sufficiently shrinking grooves formed in the hair and porous pores in the hair. Furthermore, the temperature of the hair in the heat treatment step is preferably 120°C or lower, more preferably 100°C or lower, from the viewpoint of suppressing damage to the hair. The heat treatment step is preferably 5 minutes or longer, more preferably 10 minutes or longer, and even more preferably 15 minutes or longer, from the viewpoint of sufficiently shrinking grooves formed in the hair and porous pores in the hair. Furthermore, the heat treatment step is preferably 30 minutes or shorter, more preferably 20 minutes or shorter, from the viewpoint of suppressing excessively long treatment times. The temperature of the hair in the heat treatment step and the heat treatment time may be set according to the type, quality, thickness, etc. of the hair to be treated.

[0054] According to the hair treatment method of the second embodiment described above, by further including a step of bending the hair under the condition of a curvature radius of 10 μm or more and 500 μm or less, the durability of the effects of the hair treatment solution can be further improved. Although the mechanism behind this is unclear, the following mechanism is presumed. Specifically, it is presumed that bending the hair locally causes a condition in the hair similar to the crazing phenomenon (whitening phenomenon) that occurs when a polymer film or the like is bent. By forming a localized bend in the hair and moving this bend along the longitudinal direction, crazes can be formed along the entire longitudinal direction of the hair. It is believed that when the hair becomes nanoporous due to the crazes, the hair treatment solution penetrates and is retained in the pores. As a result, the durability of the effects of the hair treatment solution can be further improved. According to the method of this embodiment, crazes can be formed using the multiple grooves formed in the forming step as base points, making it easy to form crazes in the hair. As a result, the stress applied to the hair when forming crazes in the hair can be reduced, and the amount of crazes formed in the hair can be increased. Furthermore, according to the method of the present embodiment, the amount of chemicals that cause significant damage to hair and skin used in the hair treatment solution can be further reduced, or the use of such chemicals can be eliminated. As a result, damage to hair and skin can be further suppressed. Furthermore, according to the method of the present embodiment, the durability of the effect of the hair treatment solution can be further improved, so that the frequency of visits to beauty salons, etc. can be reduced, improving convenience for users.

[0055] Furthermore, according to the method of the present embodiment, by further including a heat treatment step of heat treating the hair so that the hair temperature is 40° C. or higher and 150° C. or lower, the retention effect of the hair treatment solution can be further enhanced, and the duration of the effect of the hair treatment solution can be further improved. Furthermore, by including the heat treatment step, a decrease in the strength of the hair can be suppressed, and a decrease in the elastic modulus of the hair can be suppressed.

[0056] C. Other Embodiments The hair treatment method in each of the above embodiments is merely an example and can be modified in various ways. For example, the hair treatment method may include a step of applying at least one of water and a liquid containing a surfactant before the bending step or the shaping step. Examples of surfactant-containing liquids include, but are not limited to, soapy water, alcohol, lotion, emulsion, moisturizer, and beauty serum. Applying at least one of water and a liquid containing a surfactant to hair can adjust the surface tension and reduce the interfacial free energy, thereby further enhancing the penetration effect of the hair treatment liquid. Furthermore, applying at least one of water and a liquid containing a surfactant to hair can reduce the frictional force generated by the tool used to treat the hair during the bending step, thereby suppressing a decrease in treatment efficiency.

[0057] Furthermore, the hair treatment method may further include, for example, a step of maintaining the applied state of the hair treatment liquid after the application step and before the heat treatment step. This step may be achieved by a step of air-drying the hair. In this step, it is assumed that the hair is dried with air at about room temperature. The method of air-drying the hair is not particularly limited, but for example, a hair dryer or an air blower may be used. By further including a step of maintaining the applied state, the penetration effect of the hair treatment liquid can be enhanced. The step of maintaining the applied state of the hair treatment liquid is preferably 5 minutes or more, more preferably 10 minutes or more, from the viewpoint of sufficient penetration of the hair treatment liquid. Furthermore, the step of maintaining the applied state of the hair treatment liquid is preferably 30 minutes or less, more preferably 15 minutes or less, from the viewpoint of preventing the time required for treatment from becoming excessively long. The time for maintaining the applied state of the hair treatment liquid may be set depending on the type, quality, thickness, etc. of the hair to be treated.

[0058] After the step of maintaining the applied state of the hair treatment liquid, the method may further include a step of removing excess hair treatment liquid before the heat treatment step or after the heat treatment step. In this step, the excess hair treatment liquid may be washed away with water or a detergent, or wiped off with a towel or cloth.

[0059] FIG. 4 is a perspective view showing a schematic configuration of an appliance 100a according to another embodiment. The configuration of the appliance 100 according to the second embodiment is merely an example and can be modified in various ways. For example, as in the appliance 100a shown in FIG. 4, the first member 10 and the second member 20 may be connected to each other at their ends in the first direction D1. This configuration allows hair to be more easily sandwiched between the first member 10 and the second member 20. As a result, the efficiency of the hair bending process can be improved, and usability can also be enhanced. The hair bending appliance 100 may also include a mechanism for applying a predetermined tension to the hair. Such a mechanism may be realized, for example, by a spring, elastic member, or magnet (not shown) provided between the first member 10 and the second member 20, or may be realized using the principle of leverage. This configuration can suppress fluctuations in the value of the tension applied to the hair. [Example]

[0060] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0061] 1. Sample The hair used was white horsehair with a thickness of approximately 200 μm.

[0062] 2. Bending treatment method Fig. 5 is an explanatory diagram showing a device used to bend hair. For convenience of illustration, Fig. 5 shows only a portion of device 200. Device 200 shown in Fig. 5 has a blade 210 and four rollers 220. For convenience of explanation, Fig. 5 shows hair H to be treated. A weight (not shown) is connected to hair H to control the load.

[0063] The blades 210 correspond to the protrusions 11 in the tool 100 shown in FIG. 3 and apply tension to the hair H by local bending. Of the four rollers 220, the two rollers 220 shown at the top of the drawing correspond to the pair of receiving portions 12 in the tool 100 shown in FIG. 3, and the two rollers 220 shown at the bottom of the drawing correspond to the pair of support portions 22 in the tool 100 shown in FIG. 3. The four rollers 220 secure the hair H to prevent it from slipping and feed the hair H in the treatment direction by rotating in the directions indicated by the curved arrows in FIG. 5. The rollers 220 are connected to a speed controller (not shown) so that their rotation speeds can be changed. A user of the device 200 can freely change the treatment speed of the hair H by changing the rotation speed of the rollers 220. Because the rollers 220 are connected to the speed controller, the device 200 can feed the hair H at a constant speed. Furthermore, the user of device 200 can adjust the treatment load by adjusting the weight of a weight (not shown). Furthermore, the user of device 200 can adjust the angle φ at which hair H is bent by adjusting the degree to which blade 210 is pressed into hair H. As a result of being able to adjust the treatment load and angle φ, the bending stress applied to hair H can be adjusted.

[0064] The bending treatment of the example was carried out as follows. A sample was placed in the device 200 shown in FIG. 5. A load was applied to one end of the hair H, and the hair H was fixed by being clamped between rollers 220. The device 200 was operated to rotate the rollers 220, and the local bending generated in the hair H was moved along the longitudinal direction of the hair H, thereby treating the entire sample. A stainless steel blade was used as the blade 210. The angle θ of the blade edge was 26.3°, and the radius of curvature R of the blade edge was 100 μm. The bending angle φ of the sample was 90°, and the roller rotation speed was 20 mm / min. A load of 0.95 MPa was applied to the sample to apply tension. The bending treatment was carried out at room temperature in air, and the treatment was repeated twice.

[0065] 3. Test 1 (groove formation method: file, test content: dyeing and observation) (1) Method For the forming process, grooves were created in the hair by rubbing it with a file. A 3V mini-router with a 2.34 mm bit diameter and a 1 mm spherical grinding bit was used as the file. The file was moved back and forth along the direction perpendicular to the length of the hair while also moving along the length of the hair. This process was repeated six times. Then, for the bending process, the hair was bent using the method described above. Some samples were also prepared without the bending process. Then, dye was applied to the samples. The samples to which the dye was applied were left in a dry state. Water-based ink was used as the dye. The application was performed in air at room temperature, and the dye was left to penetrate for 25 minutes after application. The dye adhering to the hair surface was then washed off with ethanol and water. For the heat treatment process, hot air at 100°C was applied to the hair using a hair dryer for 10 minutes. The samples were then observed using an optical microscope.

[0066] (2) Results Figure 6 is an explanatory diagram showing the results of Test 1. In the sample that did not undergo the forming and bending processes, the dye was hardly retained and discoloration was observed. In contrast, in the sample that underwent the forming process, it was confirmed that the dye had penetrated into the grooves that had been formed. Furthermore, in the sample that underwent the bending process after the forming process, it was confirmed that the grooves had widened further due to bending. For this reason, it is thought that the bending process makes it easier for the dye to be retained in the grooves, and it is expected that the dyeing effect will last longer.

[0067] 4. Test 2 (Groove formation method: blade, test content: SEM image observation) (1) Method In the forming process, grooves were formed in the hair by applying a blade to the hair. The blade used was a single-cutting cutter (NT Cutter T-1P, manufactured by NT Corporation) with two pieces of tape, each about 30 μm thick, attached to the cutting edge (about 80 μm). A piece of tape, also about 30 μm thick, was attached to the sample hair. The grooves were formed by sliding the cutter along a direction perpendicular to the length of the hair. The distance between the grooves was about 2 mm. Then, in the bending process, the hair was bent using the method described above. Note that a sample was also prepared that omitted the bending process. The sample was then observed using an SEM.

[0068] (2) Results Figure 7 is an explanatory diagram showing the results of Test 2. In Figure 7, (a) shows an SEM image of a sample that underwent only the forming process, (b) shows an SEM image of a sample that underwent both the forming and bending processes, and (c) and (d) show enlarged SEM images of the groove-formed areas of the samples that underwent both the forming and bending processes. By applying the blade to the hair using the method described above, grooves measuring approximately 50 μm in length and 5 μm in width were formed on the surface of the hair. In the sample that underwent only the forming process, grooves with a shape that narrowed toward the inside of the hair were observed. In the sample that also underwent the bending process, the width of the interior of the groove was found to increase. The enlarged image confirmed that the fibrils were being stretched inside the grooves.

[0069] 5. Test 3 (groove formation method: kneading the composition, test contents: dyeing and observation) (1) Method In the forming process, grooves were formed in the hair by massaging an abrasive-containing composition into the hair. A paste containing an abrasive was used as the abrasive-containing composition. Holts® Compound MH926 (manufactured by Musashi Holt Co., Ltd.) was used as the paste. The paste contained an abrasive, a petroleum-based solvent, and a surfactant. The paste used had an average abrasive particle size of 50 μm. In the forming process, 0.1 g of paste was applied to 10 strands of hair. The hair was held by hand with a force of approximately 2 kPa and the paste was stretched 20 times along the length to massage the hair. Subsequently, in the bending process, bending treatment was performed using the method described above. Note that samples without the bending process were also prepared. Then, a dye was applied to the sample. The sample to which the dye was applied was left in a dry state. Aqueous ink was used as the dye. The application was performed at room temperature in the air, and the dye was left to penetrate for 25 minutes after application. The dye attached to the hair surface was then washed with ethanol and water. The hair was then heat-treated by using a hair dryer to blast hot air at 100°C for 10 minutes. The samples were then observed using an optical microscope. The hair color number (6-digit HTML color code) and RGB were examined in images of each sample. The hair color number was determined using the "Image Color Analysis" feature on the website "Color-site.com" (https: / / www.color-site.com / image_pickers).

[0070] (2) Results Figure 8 is an explanatory diagram showing the dyeing results in Test 3. In the sample in which the forming process was omitted, the dye was hardly retained and discoloration was observed. In contrast, in the sample in which the forming process was performed, it was confirmed that the dye had penetrated into the formed grooves. Furthermore, in the sample in which the bending process was performed after the forming process, it was confirmed that the dye was retained throughout the entire treated area. These results show that the dye is retained in the grooves formed by the forming process. In addition, it is thought that performing an additional bending process after the forming process makes it easier for the dye to be retained in the grooves, and it is expected that the dyeing effect will be more sustained.

[0071] FIG. 9 is an image showing the dyeing results of Test 3. In FIG. 9, "Untreated" indicates a sample in which the forming and bending processes were omitted, "Porosity Treatment Only" indicates a sample in which the forming process was omitted and the bending process was performed, "Notch + Porosity Treatment" indicates a sample in which the forming process (average particle size of abrasive: 3 μm) and the bending process were performed, and "Notch Only" indicates a sample in which the forming process (average particle size of abrasive: 3 μm) was performed and the bending process was omitted. The image shown in FIG. 9 also shows that performing the forming process can suppress dye fading. It was also found that performing a bending process after the forming process can further suppress dye fading. Here, when using a dye formed from natural pigments, it can be difficult to dye black hair. However, the results shown in FIG. 9 indicate that performing the forming process can also dye hair using a dye formed from natural pigments.

[0072] The hair color numbers and RGB values in Test 3 are shown in Table 1 below. Here, the smaller the RGB value, the darker the color tends to be. Furthermore, since a blue dye was used as the dye in Test 3, a small Blue value among the RGB values is an indicator that color fading of the blue dye was suppressed. Compared to samples that did not undergo either the forming process or the bending process, the RGB values, including the Blue value, were smaller in samples that underwent the forming process. Furthermore, the RGB values, including the Blue value, were even smaller in samples that underwent the bending process after the forming process. Therefore, the results in Table 1 also show that performing the forming process can suppress color fading of the dye. Furthermore, it was found that performing the bending process after the forming process can further suppress color fading of the dye.

[0073] [Table 1]

[0074] 6. Test 4 (Groove formation method: kneading composition, test content: measurement of surface roughness) (1) Method The forming process was carried out in the same manner as in Test 3, using a paste containing an abrasive. In Test 4, three samples were prepared: a sample (Sample 1) that did not undergo the forming process, a sample (Sample 2) that underwent the forming process using a paste containing an abrasive with an average particle size of 3 μm, and a paste (Sample 3) that contained an abrasive with an average particle size of 50 μm. In Test 4, no bending process was performed. Using a laser microscope, the root mean square deviation (μm) and maximum profile valley depth (μm) of the sample hairs were measured. The root mean square deviation (μm) represents the root mean square over a reference length and indicates the standard deviation of surface roughness. The maximum valley depth represents the depth of the deepest valley in the profile curve over a reference length.

[0075] Figure 10 is an explanatory diagram showing the measurement results of the root-mean-square height and maximum valley depth in Test 4. The root-mean-square height and maximum valley depth values were greater for the samples that underwent the forming process than for the samples that did not undergo the forming process, indicating that grooves were formed on the surface of the hair by the forming process. According to the root-mean-square height measurement results, the sample using a paste containing an abrasive with an average particle size of 3 μm had a greater surface roughness than the sample using a paste containing an abrasive with an average particle size of 50 μm. It was found that grooves approximately 0.4 μm deep were formed in the sample using a paste containing an abrasive with an average particle size of 3 μm. Furthermore, the maximum valley depth value was greater for the sample using a paste containing an abrasive with an average particle size of 50 μm than for the sample using a paste containing an abrasive with an average particle size of 3 μm, indicating that deeper grooves were formed.

[0076] 7. Test 5 (Groove formation method: running water, test content: measurement of groove surface roughness when abrasive particle size is changed) (1) Method In the forming process, grooves were formed in the hair by contacting the hair with water containing an abrasive. Niigata Seiki SK Polishing Powder WA (manufactured by Niigata Seiki Co., Ltd.) was used as the abrasive. The abrasive material was white alumina. Abrasives with particle sizes of #600 (particle size 25 μm), #3000 (particle size 10 μm), and #6000 (particle size 2.5 μm) were used. The particle sizes are specified in JIS R 6001-1:2017 and JIS R 6001-2:2017. 2.0 g of abrasive was dispersed in 20 g of pure water, and the forming process was carried out using the following equipment.

[0077] 11 is a perspective view showing the schematic configuration of device 300 used in Tests 5 to 8. In device 300, water in container 320 is caused to flow through hose 330 arranged vertically by liquid feed motor 310. The water in container 320 is stirred by stirrer 340, thereby maintaining the dispersion of the abrasive. In Tests 5 to 8, as the formation process, a bundle of 10 hairs H was placed and fixed in hose 330, and water containing the abrasive was allowed to flow at a flow rate of 4.1 mL / sec for 5 minutes.

[0078] In Test 5, three samples were prepared: one without a bending process (Sample 1), one with a #600 grit abrasive (Sample 2), one with a #3000 grit abrasive (Sample 3), and one with a #6000 grit abrasive (Sample 4). For each of Samples 1 to 4, one without a bending process and one with a bending process performed by the method described above after the forming process were prepared. The root-mean-square height of the hair on each sample was measured using a laser microscope to determine the surface roughness (μm).

[0079] Fig. 12 is an explanatory diagram showing the measurement results of surface roughness in Test 5. According to the results of the samples that did not undergo the bending process, the samples that underwent the forming process (Samples 2 to 4) all had larger surface roughness values than the sample that did not undergo the forming process (Sample 1), indicating that grooves were formed on the surface of the hair by the forming process. It was found that the sample (Sample 2) that used water containing an abrasive with an average particle size of 2.5 µm in the forming process had a surface roughness value that was approximately 0.3 µm larger than the sample that did not undergo the forming process (Sample 1), and grooves with a depth of approximately 0.3 µm were formed.

[0080] Table 2 below shows the particle size (μm) of the abrasive used in Test 5, the mass ratio of abrasive particles to water, and the quantity ratio of abrasive particles. For Samples 2 to 4, 2.0 g of abrasive was dispersed in 20 g of pure water. However, considering the quantity ratio, it was considered preferable to increase the mass % of abrasive contained in water when using abrasives with a particle size of 10 μm or 25 μm compared to when using abrasives with a particle size of 2.5 μm. The quantity ratio of abrasive particles in Table 2 is shown as the ratio of the number of abrasive particles contained in the dispersion of each sample, assuming the number of particles in Sample 2 (abrasive particle size: 2.5 μm, abrasive mass: 2.0 g) to be "1."

[0081] [Table 2]

[0082] 8. Test 6 (Groove formation method: running water, test content: measurement of surface roughness of grooves with different amounts of abrasive) (1) Method The forming process was carried out in the same manner as in Test 5, using a dispersion prepared using the abrasive particles and pure water in the amounts and particle sizes shown in Table 3 below. Sample 1 in Test 6 was a sample that did not undergo the forming process. For each of Samples 1 to 6, a sample that did not undergo the bending process and a sample that underwent the bending process using the method described above after the forming process were prepared. The root-mean-square height of the sample hair was measured using a laser microscope to determine the surface roughness (μm). The quantity ratio of abrasive particles in Table 3 indicates the number of abrasive particles contained in the dispersion of each sample, expressed as a ratio when the number of particles in Sample 3 (abrasive particle size: 2.5 μm, abrasive mass: 2.0 g) is set to "1."

[0083] [Table 3]

[0084] Figure 13 is an explanatory diagram showing the surface roughness measurement results in Test 6. In Test 6, the sample (Sample 3) in which 2.0 g of abrasive with a particle size of 2.5 μm was dispersed in 20 g of pure water during the formation process exhibited the highest surface roughness value. It was found that grooves approximately 0.3 to 0.5 μm deep were formed in Sample 3. The reason for the large standard deviation in Sample 3, which underwent the bending process, is likely that the grooves widened during the bending process, preventing porosity from occurring throughout the entire groove. There was almost no difference in the results between Samples 4 and 5. Furthermore, there was almost no difference in the results between Samples 2 and 6, which had the same quantity ratio of abrasive particles in water, and the samples that did not undergo the bending process. Therefore, when the number of abrasive particles in the dispersion is the same, using an abrasive with a smaller particle size tends to result in a higher surface roughness per abrasive mass percent concentration.

[0085] 9. Test 7 (groove formation method: running water, test content: tensile test) (1) Method The forming process was carried out in the same manner as in Test 5, using 10 g of abrasive with a particle size of 2.5 μm dispersed in 20 g of pure water. After the bending process was carried out using the above-mentioned method for both the sample that did not undergo the forming process and the sample that did undergo the forming process, a heat treatment process was carried out by applying hot air at 100°C to the hair using a hair dryer for 10 minutes. A sample that did not undergo the heat treatment process was also prepared. The sample that did not undergo the bending process was designated Sample 1, the sample that underwent the bending process was designated Sample 2, and the sample that underwent the bending process and the heat treatment process was designated Sample 3. The Young's modulus (MPa) and tensile strength (MPa) were measured by a tensile test. The tensile test was carried out using a benchtop universal testing machine EZ-L (Shimadzu Corporation) at a tension speed of 10 mm and room temperature.

[0086] (2) Results FIG. 14 is an explanatory diagram showing the results of Test 7. It was observed that the bending process tended to slightly decrease the modulus of elasticity and strength, but by performing the heat treatment process, the modulus of elasticity and strength were restored to values equivalent to those of samples that had not been subjected to the bending process. Furthermore, although the forming process tended to further decrease the strength, by performing the heat treatment process, it was found that the strength was restored to values equivalent to those of samples that had not been subjected to the forming or bending process. Furthermore, the modulus of elasticity of samples that had been subjected to the forming process remained almost constant.

[0087] 10. Test 8 (Groove formation method: running water, test content: static contact angle measurement) (1) Method The forming process was carried out using 10 g of abrasive with a particle size of 2.5 μm dispersed in 20 g of pure water in the same manner as in Test 5. The following samples were prepared: an untreated sample that did not undergo the forming process (Sample 1), a sample that underwent the forming process (Sample 2), a sample that underwent the bending process using the method described above after the forming process (Sample 3), a sample that was dyed using the oxidative hair dye shown below without undergoing the forming and bending processes (Sample 4), and a sample that underwent the bending process using the method described above after the forming process and then dyed with only the dye (Sample 5).

[0088] <Oxidative hair dye> Beauty Makeup Color Wild Red (Hoyu Co., Ltd.) 1st Agent Active ingredients: 5-aminoorthocresol, 2,6-diaminopyridine, 1-hydroxyethyl-4,5-diaminopyrazole sulfate Other ingredients: HEDTA·3Na2 hydrate, PG, POE oleyl ether, POE·dimethicone copolymer, POE stearyl ether, POE behenyl ether, ascorbic acid, strong ammonia water, highly polymerized PEG, stearyl alcohol, stearic acid, steartrimonium chloride, cetanol, taurine, camellia oil, theanine, sunflower oil-1, polychlorinated dimethyl dimethylene pyrrolidinium solution, sodium sulfite anhydride, monoethanolamine, fragrance Agent 2 Active ingredient: Hydrogen peroxide Other ingredients: POE cetyl ether, POE (21) lauryl ether, alkyl glycoside, citric acid, stearyl alcohol, steartrimonium chloride, cetanol, palmitic acid, phenoxyethanol, lauryl alcohol, lauryl dimethyl betaine

[0089] Dyeing of Sample 4 was carried out as follows. 40 g of Agent 1 and 88 mL of Agent 2 were placed in a container with a lid, and then Agent 1 and Agent 2 were mixed by shaking the container up and down 30 times. This mixed solution (hair treatment solution) was applied to the hair. The sample to be applied was in a dry state. The hair treatment solution was applied at room temperature in the air. After application of the hair treatment solution, it was left for 25 minutes to allow the chemical solution to penetrate. After that, the chemical solution adhering to the surface of the hair was washed with water, and then the hair was dried by applying hot air at 100°C to the hair using a hair dryer for 10 minutes.

[0090] Aqueous ink was used as the dye in Sample 5. The dye was applied at room temperature in the air and left for 25 minutes after application to allow the dye to penetrate. The dye adhering to the hair surface was then washed with ethanol and water. A heat treatment process was then performed in which hot air at 100°C was applied to the hair using a hair dryer for 10 minutes to dry it.

[0091] Static contact angle measurements were performed on each sample using an automatic microcontact angle meter, MCA-4 (Kyowa Interface Science Co., Ltd.). Static contact angle measurements were performed as follows: First, the sample hair was fixed to a glass slide and attached to the sample stage. The camera attached above the sample was used to focus the hair and the droplet needle, and the position of the sample stage was adjusted so that the droplet needle was centered on the hair. Next, while observing the camera on the side of the sample, the liquid was pushed out using pump pressure, and the size was adjusted to create a droplet of approximately 30 pL. The droplet was attached to the hair by moving the droplet needle downward, and the contact angle was measured every 20 ms from immediately after the droplet landed on the hair until 10,000 ms later. Pure water was used as the liquid, and measurements were performed at five different points on each sample.

[0092] Here, the contact angle is expressed as the angle θ between the tangent of the solid surface and the liquid. At this time, a force acts between the solid and the liquid to reduce the area of the interface, and the balance of forces leads to Young's equation shown in the following formula (1). In formula (1), γ S denotes the surface tension of the solid, and γ L denotes the surface tension of the liquid, and γ SL indicates the interfacial tension between a solid and a liquid. If the liquid spreads easily, the contact angle θ will be small, and if it spreads poorly, the contact angle θ will be large.

[0093]

number

[0094] The contact angle θ was calculated using the θ / 2 method. The radius r and height h of the droplet were determined, and the contact angle θ was calculated by doubling the angle between the line connecting the left and right endpoints of the droplet and the vertex and the solid-liquid interface. This is expressed by the following formula (2), which can be transformed to the following formula (3).

[0095]

number

[0096]

number

[0097] Figure 15 is an explanatory diagram showing the results of Test 8. Figure 15 shows the contact angle (°) 400 ms after the contact with the dye in static contact angle measurements. A comparison of Sample 1 and Sample 2 revealed that the contact angle remained almost unchanged even after the forming process. A comparison of Sample 2 and Sample 3 revealed that the contact angle increased when the bending process was performed after the forming process. This indicates that the bending process suppresses wetting and absorption, making the hair surface hydrophobic. A comparison of Sample 1 and Sample 4 revealed that the contact angle decreased in hair dyed with an oxidative hair dye. This is thought to be due to the reduction of hydrophobic 18-methyleicosanoic acid (18-MEA) originally present on the hair surface by the chemicals contained in the oxidative hair dye, resulting in hydrophilicity. In contrast, the contact angle of hair dyed with only a dye (Sample 5) remained almost unchanged compared to Sample 1. This indicates that the 18-MEA present on the hair surface was hardly lost, and hydrophobicity was maintained even after dyeing. Therefore, it was shown that by using a hair treatment method that includes a formation step of forming grooves in the hair that are 1 μm or less deep, it is possible to treat the hair while suppressing the reduction of 18-MEA present on the hair surface.

[0098] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in each embodiment corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0099] 10...first member, 11...protrusion, 12...receiving portion, 20...second member, 21...connecting portion, 22...support portion, 100, 100a...instrument, 200...device, 210...blade, 220...roller, 300...device, 310...liquid delivery motor, 320...container, 330...hose, 340...stirrer, D1...first direction, D2...second direction, H...hair, R...curvature radius

Claims

1. 1. A method of treating hair, comprising: A forming step of forming a plurality of grooves having a depth of 1 μm or less in the hair; an application step of applying a hair treatment liquid to the hair in which the plurality of grooves have been formed; A method comprising:

2. The method of claim 1 further comprising: After the forming step, The method includes a bending step of bending the hair under the condition of a radius of curvature of 10 μm or more and 500 μm or less.

3. The method of claim 1 or claim 2, further comprising: The method comprises, after the application step, a heat treatment step of heat treating the hair so that the temperature of the hair is 40°C or higher and 150°C or lower.

4. In the method according to claim 1 or claim 2, The method, wherein the plurality of grooves have a depth of at least 300 nm and not more than 500 nm.

5. In the method according to claim 1 or claim 2, The method, wherein the forming step involves contacting the hair with water containing an abrasive.

6. In the method according to claim 1 or claim 2, The method, wherein the forming step comprises massaging a composition containing an abrasive into the hair.

7. In the method according to claim 1 or claim 2, The forming step comprises applying a blade having a cutting edge of 10 μm or less to the hair.

8. In the method according to claim 1 or claim 2, In the forming step, the hair is rubbed with a file of #1000 or larger.

Images