Hair treatment agent

Abstract

To provide a hair treatment agent capable of exhibiting a superior straightening effect relative to conventional alkaline hair straighteners without requiring an alkali agent as an essential ingredient, while also reducing damage caused by hair treatment, and to provide a hair treatment method employing the hair treatment agent.SOLUTION: A hair treatment agent comprises at least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea, and a reducing agent. The compound is contained in an amount of 0.5 wt.% or more and 3 wt.% or less relative to the total weight of the hair treatment agent, and the reducing agent is contained in an amount of 1 wt.% or more and 11 wt.% or less relative to the total weight of the hair treatment agent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hair treatment agent and a hair treatment method using the hair treatment agent. [Background technology]

[0002] Conventionally, hair straightening agents contain an alkaline agent such as ammonia or monoethanolamine and a reducing agent such as ammonium thioglycolate (see, for example, Patent Document 1). In hair treatment, an alkaline agent is used to penetrate a reducing agent into the hair, and the cleavage of cystine bonds in the hair by the reducing agent makes it possible to change the shape of the hair (hair straightening).

[0003] However, the action of alkaline agents can cause damage to hair, resulting in tangles, breakage, and hardened hair after treatment, resulting in an unnatural finish. Furthermore, depending on the treatment history of the hair to be treated, such as coloring, bleaching, or perming, the hair may not be able to withstand the alkaline agents and may become frizzy. Therefore, there is a need for the development of a hair treatment agent that can suppress frizzy hair and straighten curly hair while minimizing damage to hair. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-113384 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention is intended to solve the above-mentioned problems, and aims to provide a hair treatment agent that does not require an alkaline agent, provides a better straightening effect than conventional alkaline hair straighteners, and is capable of reducing damage caused by treatment, as well as a hair treatment method using the hair treatment agent. [Means for solving the problem]

[0006] The hair treatment agent of the present invention is a hair treatment agent containing at least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea, and a reducing agent, the compound is contained in an amount of 0.5% by weight or more and 3% by weight or less relative to the total weight of the hair treatment agent, The hair treatment agent is characterized in that the reducing agent is contained in an amount ranging from 1% by weight to 11% by weight based on the total weight of the hair treatment agent.

[0007] In the hair treatment composition of the present invention, the reducing agent is preferably ammonium thioglycolate.

[0008] Furthermore, the pH of the hair treatment agent is preferably within the range of 5.8 to 8.2.

[0009] The alkalinity of the hair treatment agent is preferably 3 mL or less.

[0010] The hair treatment method of the present invention includes a treatment agent application step of applying the hair treatment agent of the present invention to hair; a step of leaving the hair treatment agent applied to the hair; a washing step of washing the hair with water after the treatment agent leaving step; A drying step of drying the washed hair; and A straightening step of straightening the dried hair using a hair styling iron at a temperature in the range of 120°C to 180°C, The washing time in the water washing step is set to 5 minutes or more. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a hair treatment agent that does not require an alkaline agent, provides a better straightening effect than conventional alkaline hair straighteners, and is capable of reducing damage caused by treatment, and a hair treatment method using the hair treatment agent. DETAILED DESCRIPTION OF THE INVENTION

[0012] The inventors focused on at least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea (hereinafter sometimes referred to as urea, etc.) as an ingredient in a hair treatment agent. Urea, etc., is known as a penetrating agent (swelling agent), and although it is rarely used in hair treatment agents, it requires the inclusion of an alkaline agent, and has been positioned as an auxiliary agent. According to the present invention, even without using an alkaline agent, it is possible to obtain a better straightening effect than conventional alkaline hair straighteners, and to reduce damage caused by treatment.

[0013] <Hair treatment ingredients> The hair treatment agent of the present invention contains at least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea, and a reducing agent in specific proportions. This will be explained in detail below.

[0014] [At least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea] At least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea is contained in a range of 0.5 wt% to 3 wt% based on the total weight of the hair treatment. The lower limit of the content is preferably 1.5 wt% or more, and the upper limit is preferably 2 wt% or less. However, it is preferable to adjust the content within this range depending on the condition of the hair to be treated (hair quality and degree of damage). The compound has the effect of softening hair. If hair is too hard, the reducing agent described below is less effective. Therefore, adding the compound to the hair treatment softens the hair, allowing the reducing agent to act effectively and successfully straighten the hair. If the content is less than 0.5 wt%, a sufficient hair lengthening effect cannot be obtained, and if it exceeds 3 wt%, the hair may be excessively damaged.

[0015] [Reducing agent] The reducing agent is contained in an amount ranging from 1% by weight to 11% by weight, based on the total weight of the hair treatment. The content of the reducing agent is preferably adjusted within this range depending on the condition of the hair to be treated (hair quality and degree of damage). If the content is less than 1% by weight, a sufficient hair lengthening effect cannot be obtained, and if it exceeds 11% by weight, the hair may be excessively damaged. Furthermore, as the concentration of the reducing agent increases, the hair tends to become straight after treatment. Therefore, if you want to achieve a naturally rounded straight look or straight hair that blends in well with newly growing curly hair (your own hair) over time, it is preferable to use a low concentration of the reducing agent.

[0016] The reducing agent is selected from the group consisting of ammonium thioglycolate, monoethanolamine thioglycolate, cysteine, cysteine ​​HCl, acetylcysteine, amidinocysteine, ammonium thiolactate, thioglycerin, cysteamine, cysteamine HCl, glyceryl thioglycolate, butyrolactone thiol, cysteamine thioglycolate, sodium sulfite, sodium bisulfite, and mixtures thereof. In the hair treatment agent of the present invention, the reducing agent is preferably ammonium thioglycolate.

[0017] In addition to the above-mentioned components, the hair treatment composition of the present invention may contain any other components commonly used in cosmetics, pharmaceuticals, etc., within the range that does not impair the effects of the present invention. Such components may include, for example, cationic polymers, amino acids, peptides, proteins, sequestering agents, oils, powder components, surfactants, pH adjusters, thickeners, powder components, fragrances, powder components, and pigments.

[0018] The composition, pH, and alkalinity of the hair treatment agent can be adjusted within the above ranges depending on the condition of the hair to be treated (hair quality and degree of damage). The condition of the hair is determined by factors such as whether or not it has been colored, age, and hair thickness, and the composition, pH, and alkalinity of the hair treatment agent are adjusted according to these conditions. The hair treatment agent of the present invention preferably has a pH in the range of 5.8 to 8.2. At a pH below 5.8, the reducing agent's activity is further weakened, resulting in a treatment agent that requires a leaving time of 30 minutes or more or requires heating in the treatment agent leaving step described below. On the other hand, a pH above 8.2 may damage the hair. Within the above pH range, for example, if the hair is severely damaged, a hair treatment agent with a pH close to the neutral range is preferred, while if the hair is healthy, a hair treatment agent with a low pH is preferred. To adjust the pH of the hair treatment agent to the above range, an alkaline agent or the like can be used. The alkaline agent is not particularly limited, but ammonia, monoethanolamine, triethanolamine, sodium bicarbonate, and arginine (basic amino acid) can be used. The hair treatment agent of the present invention can significantly reduce the alkaline agent content compared to conventional products. Even with a low alkaline agent content, a sufficient straightening effect can be maintained and the hair does not become stiff, allowing for hair straightening with a natural straightening effect.

[0019] The alkalinity of the hair treatment agent of the present invention is preferably 3 mL or less. Here, "alkalinity" refers to the volume (unit: mL) of a 0.1 N (0.1 mol / L) hydrochloric acid standard solution required to neutralize 1 g of the hair treatment agent. The alkalinity preferably has a lower limit exceeding 0.3 mL, and an upper limit of 1 mL or less.

[0020] The formulation of the hair treatment agent according to the present invention is not particularly limited as long as the desired effect is sufficiently exhibited, and it may be in the form of a liquid, emulsion, gel, foam, cream, or the like. However, from the viewpoints of preventing dripping and adhesion to hair upon application, it is desirable for the agent to be in the form of an emulsion or cream.

[0021] <Hair treatment method> The hair treatment method of the present invention essentially comprises the steps of: (1) applying the above-described hair treatment agent to the hair; (2) leaving the applied hair to allow the hair treatment agent to act sufficiently on the hair; (3) rinsing the hair with water to wash away the hair treatment agent; (4) drying the hair; and (5) straightening the hair with a hair styling iron.

[0022] [Treatment agent application process] The hair treatment agent of the present invention can be applied to wet hair, but is preferably applied to dry hair (dry hair) before shampooing. Application to wet hair dilutes the urea concentration, so application to dry hair is preferred. Unless the hair is extremely dirty, shampooing before applying the hair treatment agent is unnecessary. When applying the hair treatment agent after shampooing, it is preferable to remove any moisture with a towel, dry the hair with a hair dryer, or the like, and then apply the agent to dry hair.

[0023] [Treatment agent leaving process] After application, the hair treatment is left at room temperature (approximately 25°C) for 10 to 30 minutes to allow the hair treatment to act on the hair. If the leaving time is less than 10 minutes, a sufficient hair lengthening effect cannot be obtained, while if the leaving time is more than 30 minutes, further improvement in the hair straightening effect commensurate with the leaving time cannot be expected.

[0024] [Washing process] The hair is rinsed with cold or lukewarm water to wash away the hair treatment agent. Rinsing the hair treatment agent from the hair makes it easier to dry and handle the hair. In this washing step, the washing time must be at least 5 minutes. The hair treatment agent of the present invention, which contains a compound such as urea, safely achieves straightening effects at a lower pH (pH 5.8 to pH 8.2) than conventional products. However, due to the lower pH, washing with water must be performed for at least 5 minutes. To achieve a sufficient straightening effect, sufficient reducing action (reductive cleavage of disulfide bonds) is required. The hair treatment agent of the present invention has a low pH, so its reducing action is weak. However, sufficient reducing action can be achieved by washing with water for at least 5 minutes. The greater the hair volume and the smaller the amount of water used during washing, the longer the washing time is preferred. The washing time is preferably within the range of 5 to 10 minutes.

[0025] [Drying process] After rinsing with water, wipe off the water with a towel and then dry with a hair dryer.

[0026] [Correcting process] Depending on the condition of the hair, a hair styling iron heated to a temperature in the range of 120 to 180°C is used to apply mechanical force and heat to the hair to straighten it. By using the hair treatment agent of the present invention containing a compound such as urea, the iron temperature can be lowered below the conventional temperature (140 to 200°C). By using the hair treatment agent of the present invention, a sufficient straightening effect can be obtained even with an iron temperature in the low temperature range.

[0027] According to the hair treatment method of the present invention, by adjusting the content of at least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea, and a reducing agent within a specific range, a better straightening effect (hair lengthening effect) can be obtained and damage caused by treatment can be reduced compared to conventional alkaline hair straighteners. Furthermore, by rinsing the hair treatment agent with water before the drying and straightening steps, drying is facilitated and the hair is easy to handle during the straightening step. [Example]

[0028] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these.

[0029] [Example 1] A cream-like hair treatment was prepared containing 1.75% by weight of urea and 7% by weight of ammonium thioglycolate. The pH of the resulting hair treatment was 8.2, and the alkalinity was 1 mL. This hair treatment was used to treat dark hair (less damaged hair) at levels 3-5 on the hair coloring level scale proposed by the Japan Hair Color Association (JHCA).

[0030] The treatment agent was applied to the dry hair (black hair). After application, the hair treatment agent was left at room temperature (approximately 25°C) for 30 minutes to allow the hair treatment agent to act on the hair. The hair was then rinsed with lukewarm water at 38°C for 10 minutes to rinse the hair treatment agent from the hair. The hair was then wiped dry with a towel and dried with a hair dryer. The dried hair was then straightened by applying mechanical force and heat with a hair styling iron heated to 180°C. By using the hair treatment agent of the present invention, a sufficient straightening effect could be obtained even with an iron temperature as low as 140°C. Furthermore, the treated hair had strong elasticity when wet, and there was little damage from the treatment.

[0031] [Example 2] A cream-type hair treatment was prepared containing 0.5% by weight of urea and 3.5% by weight of ammonium thioglycolate. The pH of the resulting hair treatment was 7.0, and the alkalinity was nearly 0 mL. This hair treatment was used to treat brown to blonde hair (highly damaged hair) at levels 12-14 on the hair coloring level scale proposed by the Japan Hair Color Association (JHCA).

[0032] The treatment agent was applied to the dry hair (highly damaged hair). After application, the hair treatment agent was left at room temperature (approximately 25°C) for 20 minutes to allow the hair treatment agent to act on the hair. The hair was then rinsed with lukewarm water at 38°C for 10 minutes to rinse the hair treatment agent from the hair, and the water was wiped off with a towel and then dried with a hair dryer. Next, the dried hair was straightened by applying mechanical force and heat with a hair straightening iron heated to 140°C. By using the hair treatment agent of the present invention, a safe and sufficient straightening effect was obtained on highly damaged hair that was difficult to treat with conventional alkaline hair straighteners, and the treated hair suffered almost no damage from the treatment.

[0033] When hair treatment was carried out in the same manner, good results were obtained for the combination of hair in the state shown in Table 1 and the hair treatment composition. The alkalinity of the hair treatment shown in Table 1 was in the range of 0 mL to 1 mL. Note that, although urea was used as the urea-like compound in this example, similar results could be obtained by using hydroxyethyl urea, hydroxymethyl urea, or hydroxypropyl urea instead of urea.

[0034] [Table 1]

[0035] [Comparative Example 1] An alkaline hair straightener was used. This hair straightener does not contain urea, and is a hair treatment agent containing 10% by weight of ammonium thioglycolate, a pH of 9.5, and an alkalinity of 6 mL. Using this hair treatment agent, the following treatment was carried out on black hair (less damaged hair) that was rated at level 3-5 on the hair coloring level scale proposed by the Japan Hair Color Association (JHCA).

[0036] The hair (black hair) was pre-washed with shampoo and then the remaining water was removed with a towel. The treatment agent was applied to this towel-dried hair. After application of the hair treatment agent, the hair was left at room temperature (approximately 25°C) for 30 minutes to allow the hair treatment agent to act on the hair. The hair was then rinsed with lukewarm water at 38°C for 3 minutes, the hair treatment agent was washed off the hair, the water was wiped off with a towel, and the hair was dried with a hair dryer. Next, the dried hair was straightened by applying mechanical force and heat with a hair styling iron heated to 180°C. When the hair treatment agent of Comparative Example 1 was used, the hair could not be sufficiently straightened at an iron temperature of 140°C, and it was necessary to increase the iron temperature to 180°C or higher. Furthermore, the treated hair had no elasticity at all, and frizz occurred in places.

[0037] Comparative Example 2 An acidic hair straightener was used. This hair straightener does not contain urea, and is a hair treatment agent with 7% by weight of ammonium thioglycolate, a pH of 5.5, and an alkalinity of 0 mL. Using this hair treatment agent, the following treatment was carried out on black hair (less damaged hair) that was rated at level 3-5 on the hair coloring level scale proposed by the Japan Hair Color Association (JHCA).

[0038] The hair (black hair) was pre-washed with shampoo and then the remaining water was removed with a towel. The treatment agent was applied to this towel-dried hair. After application of the hair treatment agent, the hair was left at room temperature (approximately 25°C) for 30 minutes to allow the hair treatment agent to act on the hair. The hair was then rinsed with lukewarm water at 38°C for 10 minutes, the hair treatment agent was washed off the hair, the water was wiped off with a towel, and the hair was dried with a hair dryer. Next, the dried hair was straightened by applying mechanical force and heat with a hair styling iron heated to 180°C. When the hair treatment agent of Comparative Example 2 was used, the desired straightening effect was not achieved, and after 1 to 2 weeks, most of the hair reverted to its original curly state (reverting).

[0039] As described above, the present invention can provide a hair treatment agent and a hair treatment method that do not require an alkaline agent, can achieve better straightening effects than conventional alkaline hair straighteners, and can reduce damage caused by treatment.

Claims

1. A hair treatment agent containing at least one compound selected from urea, hydroxyethyl urea, hydroxymethyl urea, and hydroxypropyl urea, and a reducing agent, the compound is contained in an amount of 0.5% by weight or more and 3% by weight or less relative to the total weight of the hair treatment agent, A hair treatment agent, characterized in that the reducing agent is contained in an amount ranging from 1% by weight to 11% by weight, both inclusive, based on the total weight of the hair treatment agent.

2. 2. The hair treatment composition according to claim 1, wherein the reducing agent is ammonium thioglycolate.

3. 3. The hair treatment composition according to claim 1, wherein the pH of the hair treatment composition is in the range of 5.8 to 8.

2.

4. The hair treatment agent according to claim 1 or 2, wherein the alkalinity of the hair treatment agent is 3 mL or less.

5. a treatment application step of applying the hair treatment agent according to any one of claims 1 to 4 to hair; a step of leaving the hair treatment agent applied to the hair; a washing step of washing the hair with water after the treatment agent leaving step; A drying step of drying the washed hair; and a straightening step of straightening the dried hair using a hair styling iron at a temperature in the range of 120°C to 180°C, A hair treatment method characterized in that the washing time in the water washing step is 5 minutes or more.

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