Composition for suppressing moisture loss from hair

Abstract

The present invention provides a hair composition for daily use on hair, which has excellent moisture retention capabilities in hair, and can suppress moisture loss from hair caused by daily hair care such as drying with a hairdryer after washing, and heat treatment with a hair iron, thereby protecting hair from damage caused by such daily care and heat treatment. [Solution] A composition for suppressing moisture loss from hair, comprising one or more selected from the group consisting of acylated hyaluronic acid having an acyl group with 1 to 4 carbon atoms and its salts, and water.

Description

Technical Field

[0003] , , ,

[0001] The present invention relates to a hair composition, and more particularly to a composition used for suppressing moisture loss in hair and having excellent moisture retention power in hair.

Background Art

[0002] It is known that hair is damaged not only by chemical treatments such as hair dyeing and permanent waving, but also by daily hair care such as ultraviolet exposure, hair washing, and drying. In damaged hair, damage and peeling of the cuticle occur, resulting in frizz and a decrease in elasticity, and the appearance beauty is impaired. It has also been reported that the moisture content of hair decreases and the tensile strength of hair decreases. Regarding such hair damage, cationic surfactants and cationic polymers are used to suppress static electricity on the hair surface to suppress frizz and impart good combability. Esters, silicone oils, vegetable oils, sterols, etc. are used to form an oily film on the hair surface to impart smoothness and gloss and improve finger combability and combability. As a hair treatment agent composition that imparts a sufficient smooth feeling and an effect of suppressing frizz to hair and has no stickiness, a hair treatment agent composition containing acetylated hyaluronic acid has been proposed (Patent Document 1). Recently, as a transparent anhydrous composition for caring for hair so that it remains firm, shiny, and elastic, a composition containing acetylated hyaluronic acid or its salt and propylene glycol and having a water content of less than 5% by mass based on the total amount of the composition has been proposed (Patent Document 2).

[0003] However, there is no known hair composition that can suppress moisture loss in hair caused by daily hair care such as drying with a hair dryer after hair washing or hair treatment with a hair iron, etc., and protect hair from damage caused by daily hair care and heat treatment. Patent documents 1 and 2 make no mention whatsoever of the effect of suppressing moisture loss in hair due to daily hair care or heat treatment. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-228360 [Patent Document 2] Special Publication No. 2023-549118 [Overview of the project] [Problems that the invention aims to solve]

[0005] Therefore, the present invention aims to provide a hair composition for daily use on hair that has excellent moisture retention capacity in hair, suppresses moisture loss from hair caused by daily hair care such as drying with a hairdryer after washing, and hair treatments such as using a hair iron, thereby protecting hair from damage caused by such daily care and heat treatment. [Means for solving the problem]

[0006] The present inventors, after diligently studying to solve the above problems, discovered that a composition containing one or more acylated hyaluronic acid and its salts having acyl groups with 1 to 4 carbon atoms, and water, has excellent moisture retention capabilities and can effectively suppress moisture loss from hair when drying with a hairdryer or styling with a hair iron, not only when used without rinsing but also when used after rinsing. Further studies led to the completion of the present invention.

[0007] In other words, the present invention relates to the following. [1] A composition for suppressing moisture loss from hair, comprising one or more selected from the group consisting of acylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms and salts thereof, and water. [2] The composition according to [1], wherein the acylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms is acetylated hyaluronic acid. [3] The composition according to [2], wherein the intrinsic viscosity of the acetylated hyaluronic acid is 0.5 dL / g to 2.8 dL / g. [4] The composition according to [2] or [3], wherein the acetylation rate of acetylated hyaluronic acid is 2.6 to 3.9 per repeating unit of hyaluronic acid. [5] A composition according to any one of [1] to [4], which is washed off after use. [6] The composition according to any one of [1] to [5], wherein the moisture loss of the hair is due to heat. [Effects of the Invention]

[0008] The present invention provides a hair composition for daily use on hair that has excellent moisture retention capabilities in hair, suppresses moisture loss from hair caused by daily hair care such as drying with a hairdryer after washing, and hair treatment with a hair iron, and can protect hair from damage caused by such daily care and heat treatment. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows the percentage of moisture loss in hair when treated with the sample solution and heated at 100°C and 160°C, respectively, in Test Example 1, without rinsing. [Figure 2] Figure 2 shows the percentage of moisture loss in hair when treated with each sample solution and then heated at 100°C and 160°C, respectively, in Test Example 2. [Figure 3] Figure 3 shows the relationship between the rate of suppression of hair moisture loss and the concentration of acetylated sodium hyaluronate in Test Example 3. [Modes for carrying out the invention]

[0010] The present invention provides a hair composition for daily use on hair, which is a composition for suppressing moisture loss in hair (hereinafter also referred to as "the hair composition of the present invention" in this specification). In this specification, "hair composition used on hair on a daily basis" means a composition used on hair on a daily basis, such as for washing hair, caring for hair after washing, or styling hair. The hair composition of the present invention contains one or more selected from the group consisting of acylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms and its salts, and water.

[0011] The acylated hyaluronic acid having acyl groups with 1 to 4 carbon atoms contained in the hair composition of the present invention is a derivative of hyaluronic acid in which some of the hydroxyl groups in N-acetylglucosamine and D-glucuronic acid, which constitute hyaluronic acid, are replaced with acyl groups with 1 to 4 carbon atoms. Examples of acyl groups having 1 to 4 carbon atoms include methanol (formyl), ethanol (acetyl), propanoyl (propionyl), 2-methylethanol (isopropanoyl), butanoyl (butyryl), and 2-methylpropanoyl (isobutanoyl). The substitution of hydroxyl groups in hyaluronic acid with the aforementioned acyl groups (acylation) can be carried out by known acylation methods, such as a reaction using an acylation reagent corresponding to the desired acyl group. In the present invention, the acylation rate by acyl groups having 1 to 4 carbon atoms is preferably 2 to 3.9 per 4 hydroxyl groups present in the repeating unit of hyaluronic acid [D-glucuronic acid-β-1,3-DN-acetylglucosamine-β-1,4], and more preferably 2.5 to 3.9.

[0012] Acylated hyaluronic acid having an acyl group with 1 to 4 carbon atoms can also be used in the form of a salt. The salt of the acylated hyaluronic acid is not particularly limited as long as it is a pharmaceutically acceptable salt and can be used in a composition for hair or skin. For example, alkali metal salts such as sodium salt and potassium salt; alkaline earth metal salts such as calcium salt and magnesium salt; ammonium salt; alkanolamine salts such as monoethanolamine salt and diethanolamine salt are exemplified. For the purpose of the present invention, an alkali metal salt is preferably used, and a sodium salt is more preferably used. The salt of acylated hyaluronic acid having an acyl group with 1 to 4 carbon atoms can be produced according to a method known per se from the acylated hyaluronic acid.

[0013] In the present invention, as the acylated hyaluronic acid having an acyl group with 1 to 4 carbon atoms, acetylated hyaluronic acid having an acetyl group as the acyl group can be preferably used. For the purpose of the present invention, the intrinsic viscosity of acetylated hyaluronic acid is preferably 0.5 dL / g to 2.8 dL / g, more preferably 0.8 dL / g to 1.5 dL / g. Here, the intrinsic viscosity of acetylated hyaluronic acid can be determined by the first method described in the Pharmaceutical Excipients Raw Material Standards 2006 General Test Method 53. Viscosity Measurement Method, and from that value, the viscosity average molecular weight of acetylated hyaluronic acid can be determined. In addition, the acetylation rate of acetylated hyaluronic acid (the substitution rate of acetyl groups at the 4 hydroxyl groups present in the repeating unit of hyaluronic acid [D-glucuronic acid-β-1,3-D-N-acetylglucosamine-β-1,4]) is preferably 2.6 to 3.9, more preferably 2.8 to 3.8. The above-mentioned acetylated hyaluronic acid can be produced and purified according to a production method known per se, for example, the method described in JP-A-8-053501.

[0014] In addition, the salt of acetylated hyaluronic acid is not particularly limited as long as it is a pharmaceutically acceptable salt. For example, alkali metal salts such as sodium salt and potassium salt; alkaline earth metal salts such as calcium salt and magnesium salt; ammonium salt; alkanolamine salts such as monoethanolamine salt and diethanolamine salt are exemplified. For the purpose of the present invention, an alkali metal salt is preferably used, and a sodium salt is more preferably used. The salt of acetylated hyaluronic acid can also be produced according to a method known per se from acetylated hyaluronic acid.

[0015] In the hair composition of the present invention, the acetylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms and its salt may be selected singly and used alone, or two or more kinds may be selected and used in combination. The acetylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms and its salt, for example, acetylated hyaluronic acid and its salt can be produced and used according to a production method known per se as described above, but commercially available products provided by Fujimoto Chemical Products Co., Ltd. etc. can also be used. The content of one or more selected from the group consisting of acetylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms and its salt in the hair composition of the present invention is preferably 0.001% by weight to 5% by weight, more preferably 0.01% by weight to 1% by weight, and still more preferably 0.01% by weight to 0.1% by weight based on the total weight of the composition. When the content of one or more selected from the group consisting of acetylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms and its salt is within the above range, the water retention effect after using the hair composition of the present invention is good both when used without rinsing and when used after rinsing, and the water loss during heat treatment of the hair such as drying with a hair dryer or treatment with a hair iron can be preferably suppressed, and the use feeling etc. are less impaired.

[0016] The hair composition of the present invention contains water in addition to one or more selected from the group consisting of acylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms and its salts, and can be provided in dosage forms such as aqueous lotion, aqueous gel, oil-in-water emulsion lotion, water-in-oil emulsion lotion, oil-in-water cream, and water-in-oil cream. The water contained in the hair composition of the present invention is purified water suitable for the manufacture of the hair composition, such as distilled water or deionized water. The water content in the hair composition of the present invention is set to the amount necessary to form a dosage form containing the water described above.

[0017] The hair composition of the present invention contains, to the extent that it does not impair the characteristics of the present invention, anionic surfactants such as sodium lauryl sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium α-olefin sulfonate, disodium lauryl sulfosuccinate, disodium lauryl polyoxyethylene sulfosuccinate, sodium N-lauroyl-N-methyl-β-alanine, disodium N-coconut oil fatty acid acyl glutamate, sodium N-coconut oil fatty acid acylmethyl taurate; and 2-alkyl-N-carboxymethyl-N - Amphoteric surfactants such as hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyl betaine, lauric acid amidopropyl-N,N-dimethylammonium-N-(2-hydroxypropyl) sulfonate; nonionic surfactants such as lauric acid diethanolamide, coconut oil fatty acid diethanolamide, glyceryl monostearate, polyoxyethylene (20) cetyl ether, polyoxyethylene (20) monolaurate, polyoxyethylene (20) monostearate, polyoxyethylene (20) monooleate; cationic surfactants such as dialkyl (C12~18) dimethylammonium chloride, distearyldimethylammonium chloride, stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, behenyltrimethylammonium chloride, dimethylaminopropyl stearate, etc., common hair cleansing ingredients, hydroxyethylcellulose dimethyldiallylammonium chloride, vinylpyrrolidone-N,N-dimethylaminoethyl methacrylate copolymer diethyl sulfate, hydroxypropyltrimonium hyaluronate, Cationic polymers such as O-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethylcellulose chloride; vegetable oils such as almond oil, avocado oil, olive oil, safflower oil, camellia seed oil, sunflower oil, grape seed oil, and macadamia nut oil; fatty acids such as oleic acid and lanolin fatty acid; esters such as phytosteryl isostearate, phytosteryl oleate, and N-lauroyl-L-glutamic acid di(phytosteryl / behenyl / 2-octyldodecyl); sterols such as cholesterol and phytosterols;It may contain silicone oils such as aminopropylmethylpolysiloxane, aminoethylaminopropylmethylsiloxane / dimethylsiloxane copolymer, methylpolysiloxane, bisaminopropylmethylpolysiloxane, and biscetearylaminoethylaminopropylmethylsiloxane / dimethylsiloxane copolymer; basic amino acids such as arginine and histidine; vitamins such as panthenol and pantothenic acid; hydrolyzed proteins such as hydrolyzed collagen, hydrolyzed conchiolin, hydrolyzed silk, and hydrolyzed keratin; common hair conditioning agents; aliphatic alcohols such as cetanol and cetostearyl alcohol; polyhydric alcohols such as glycerin and 1,3-butylene glycol; thickeners such as hydroxyethylcellulose and carboxyvinyl polymer; pH adjusters such as lactic acid and sodium lactate; and preservatives such as phenoxyethanol and methyl parahydroxybenzoate; and other common additives for hair preparations. The general hair cleansing ingredients, general hair conditioning agents, and general hair preparation additives mentioned above can be used one or more times as needed.

[0018] The hair composition of the present invention can be provided as a product used for daily hair washing and care, such as hair shampoo, hair rinse, hair conditioner, hair treatment, leave-in treatment, and hair cream, and can be provided as either a leave-in product or a rinse-off product.

[0019] The hair composition of the present invention, when used on hair on a daily basis, either without rinsing or after rinsing, can suppress moisture loss from the hair caused by daily hair care such as drying with a hairdryer after washing, or by heat treatment of the hair with a hair iron, etc., and can protect the hair from damage caused by such daily care and heat treatment. [Examples]

[0020] The present invention will be described in more detail below with reference to test examples and embodiments.

[0021] [Test Example 1] Investigation of the effect of acylated hyaluronic acid on the moisture retention capacity of hair when used without rinsing. (1) Sample As the acylated hyaluronic acid, we used "acetylated sodium hyaluronate" (intrinsic viscosity = 1.0 dL / g, degree of acetylation = 3.38) (Fujimoto Chemical Products Co., Ltd.), which is in salt form, and prepared a 0.1% by weight aqueous solution of it as the sample. Purified water was used as a control. (2) Hair treatment After thoroughly washing the hair with a 1% by weight sodium dodecyl sulfate (SDS) aqueous solution, the hair was air-dried to prepare a hair bundle of approximately 2 g. The hair bundle was then immersed in 50 mL each of the sample solution and the control solution for 5 minutes. The sample solution and other residues were removed by lightly sandwiching the hair bundle with a Kimtowel, and then dried with a hairdryer for 2 minutes. The hair bundle was then dried overnight at room temperature to acclimate to the room temperature environment. The treatment of hair with the sample solution and the control solution was performed with n=3 each. (3) Measurement of hair moisture loss rate The hair bundles processed in (2) above were cut to approximately 3 cm lengths, and 0.30 g were placed on the drying tray of a heated drying moisture meter (A&D Co., Ltd.). The bundles were heated at 100°C for 3 minutes, simulating drying with a hair dryer, and then heated at 160°C for 3 minutes, simulating treatment with a hair iron. The weight of the hair was measured before and after heating. The average weight of the hair before heating (W) and the average weight 120 seconds after the start of heating at 100°C and 160°C (Dtemp) were used to calculate the moisture loss rate of the hair using the following formula (I). Student's t-test was performed between the control group and the sample solution treatment group to determine the moisture loss rate of the hair. The measurement results are shown in Figure 1 as mean ± standard deviation. In the figure, "AcHA" refers to acetylated sodium hyaluronate, and "%" refers to weight percent. "*" indicates a statistically significant difference between the sample and the control (p<0.05).

[0022]

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[0023] As shown in Figure 1, immersion of hair in a 0.1 wt% aqueous solution of acetylated sodium hyaluronate significantly suppressed moisture loss of the hair when heated at 100°C and 160°C (p<0.05).

[0024] [Test Example 2] Investigation of the effect of acylated hyaluronic acid on the moisture retention capacity of hair when used after rinsing. (1) Sample As the acylated hyaluronic acid, "acetylated sodium hyaluronate" (intrinsic viscosity = 1.0 dL / g, degree of acetylation = 3.38) (Fujimoto Chemical Products Co., Ltd.), which is in salt form, was used. 0.1% by weight aqueous solutions of the aforementioned acetylated sodium hyaluronate, "oligohyaluronic acid" (Fujimoto Chemical Products Co., Ltd.), and "hyaluronic acid" (Fujimoto Chemical Products Co., Ltd.) were prepared and used as samples. Purified water was used as a control. (2) Hair treatment Hair bundles prepared in the same manner as in Test Example 1 were immersed in 50 mL each of the sample solution and control for 5 minutes. After that, the sample solution and other residues were removed by lightly pressing the hair bundles with Kimwipes. Next, the hair bundles were rinsed under running tap water for 30 seconds, and then the moisture was removed by lightly pressing the hair bundles with Kimwipes. Finally, the hair bundles were dried at room temperature overnight to allow them to acclimate to the room temperature environment. The treatment of hair with the sample solution and control was performed with n=3 each. (3) Measurement of hair moisture loss rate The hair treated in (2) above was cut to approximately 3 cm, and, as in Test Example 1, 0.30 g was heated at 100°C for 3 minutes, then at 160°C for 3 minutes using a heat-drying moisture meter (A&D Company, Limited), and the moisture loss rate of the hair due to heating at 100°C and 160°C was calculated. Student's t-test was performed on the moisture loss rate of the hair between the control and each sample solution treatment group. The measurement results are shown in Figure 2 as mean ± standard deviation. In the figure, "AcHA" refers to acetylated sodium hyaluronate, "Oligo HA" refers to oligo-hyaluronic acid, "HA" refers to hyaluronic acid, and "%" refers to weight percent. "*" indicates a statistically significant difference between the compared groups at p<0.05, and "**" indicates a statistically significant difference between the compared groups at p<0.01.

[0025] As shown in Figure 2, even after immersing hair in an aqueous solution of acetylated sodium hyaluronate and then rinsing it off, the water loss of hair due to heating at 100°C and 160°C was significantly suppressed compared to the control treated with purified water (p<0.01). Furthermore, the inhibitory effect of acetylated sodium hyaluronate on moisture loss in hair due to heating was greater than that of hyaluronic acid and oligo-hyaluronic acid (at 100°C, it was significantly greater than the hyaluronic acid aqueous solution treatment group and the oligo-hyaluronic acid aqueous solution treatment group, with p<0.01; and at 160°C, it was significantly greater than the hyaluronic acid aqueous solution treatment group, with p<0.01).

[0026] [Test Example 3] Investigation of the effect of acylated hyaluronic acid concentration on the effect of suppressing moisture loss in hair. As the acylated hyaluronic acid, we used "acetylated sodium hyaluronate" (intrinsic viscosity = 1.0 dL / g, degree of acetylation = 3.38) (Fujimoto Chemical Products Co., Ltd.), which is in salt form. Three grams of Asian hair were thoroughly washed with a 1% by weight sodium dodecyl sulfate (SDS) aqueous solution, air-dried, and then bundled into hair strands. These bundles were then immersed in 0.001% by weight, 0.01% by weight, 0.05% by weight, and 0.1% by weight aqueous solutions of acetylated sodium hyaluronate, respectively. After standing at room temperature for 5 minutes, they were washed in tap water with vigorous shaking for 30 seconds. Excess water was then removed with tissue paper, and the bundles were dried with a hairdryer for 2 minutes. They were then left to stand at room temperature overnight to acclimate to the measurement environment (n=5 for each). As a control, purified water was used instead of the acetylated sodium hyaluronate aqueous solution and the same treatment was performed (n=5). The hair sample was cut to approximately 3 cm, weighed out 0.30 g, placed on the drying dish of a heated drying type moisture meter (A&D Company, Limited), and heated at 100°C and 160°C for 3 minutes each. The amount of moisture loss from the hair was then determined in the same manner as in Test Example 1. Student's t-test was performed on the hair moisture loss rate between the control group and each sample solution treatment group. Figure 3 shows the mean ± standard deviation of the water loss rate when each hair sample, including the control and those immersed in aqueous solutions of acetylated sodium hyaluronate at each concentration, was heated at 160°C. In the figure, "AcHA" represents acetylated sodium hyaluronate, and "%" represents weight percent. "*" indicates a statistically significant difference between the control and the sample at p<0.05, and "**" indicates a statistically significant difference between the control and the sample at p<0.01.

[0027] As shown in Figure 3, when heated at 160°C, hair immersed in 0.001% to 0.1% by weight aqueous solution of acetylated sodium hyaluronate showed a significantly lower water loss rate compared to control hair (significant at p<0.05 for 0.001%, 0.01%, and 0.05%, and significant at p<0.01 for 0.1%). Furthermore, although not shown in the figure, when heated to 100°C, a significant reduction in water loss rate was observed in hair immersed in a 0.1% by weight aqueous solution of acetylated sodium hyaluronate compared to the control (significant at p<0.01). The results from Test Example 3 suggest that when immersing and rinsing with an aqueous solution of acetylated sodium hyaluronate, the loss of moisture due to heat treatment at 160°C (equivalent to heat treatment with a hair iron) is suppressed at a concentration of 0.001% to 0.1% by weight. Furthermore, it was suggested that the loss of moisture due to heating at 100°C (equivalent to drying with a hair dryer) could be suppressed by immersion treatment in a 0.1% by weight aqueous solution of acetylated sodium hyaluronate.

[0028] The results from Test Examples 1-3 suggest that acetylated sodium hyaluronate has the effect of suppressing moisture loss in hair due to heating. Furthermore, it was suggested that the aforementioned effect of acetylated sodium hyaluronate is also observed even after the hair has been washed. Furthermore, the inhibitory effect of acetylated sodium hyaluronate on moisture loss in hair due to heating was suggested to be greater than that of hyaluronic acid. Therefore, it was suggested that by washing hair with a hair composition containing acetylated sodium hyaluronate, or by applying the hair composition to hair after washing, it is possible to suppress moisture loss from hair caused by daily hair care such as drying with a hairdryer after washing, and thereby protect hair from damage caused by such daily care. Furthermore, it was suggested that acetylated sodium hyaluronate can more effectively suppress moisture loss caused by heat treatment of hair using hair irons, etc., and that washing hair with a hair composition containing acetylated sodium hyaluronate, or applying the hair composition to hair after washing, can protect hair from damage caused by more severe heat treatments such as heat treatment using hair irons, etc.

[0029] Next, examples of the composition of the present invention are given below.

[0030] [Example 1] Leave-in treatment Prepare the leave-in treatment as follows, following the formula shown in Table 1. Specifically, the oil phase components (1) to (4) are mixed and heated to approximately 80°C to make them uniform. The aqueous phase components (5) to (7) are also mixed and heated to approximately 80°C to dissolve uniformly. The oil phase components are gradually added to the aqueous phase components, mixed while stirring to emulsify, and then cooled. At 50°C, (8) to (10) are added and mixed uniformly.

[0031] [Table 1]

[0032] [Example 2] Shampoo Prepare the shampoo as follows, according to the formulation shown in Table 2. Specifically, (1) and (2) are mixed uniformly at approximately 25°C, then heated to approximately 80°C, and (3) to (8) are added sequentially, stirring and mixing until uniform, and then cooled. At 50°C, (10) is dissolved in (9) and added, and after uniform mixing, (11) is added and uniform mixing is performed.

[0033] [Table 2]

[0034] [Example 3] Conditioner Prepare the conditioner as follows, according to the formulation shown in Table 3. Specifically, (1) to (3) are mixed, heated to 80°C to make it homogeneous, and (4), heated to 80°C, is gradually added, stirred, mixed, and emulsified. Then it is cooled, (6) is dissolved in (5) at 50°C and added, mixed homogeneously, and then (7) is added and mixed homogeneously.

[0035] [Table 3]

[0036] Each of the hair compositions in Examples 1-3 contains 0.1% by weight of acetylated sodium hyaluronate. Based on the results shown in Test Examples 1-3, it is expected that these compositions can effectively suppress moisture loss from hair caused by drying with a hairdryer after washing or by heat treatment with a hair iron. Therefore, it is expected that using the hair compositions in Examples 1-3 during or after washing will protect hair from damage caused by daily care and heat treatment. [Industrial applicability]

[0037] As described in detail above, the present invention provides a hair composition for daily use on hair that has excellent moisture retention capacity in hair, suppresses moisture loss from hair during daily hair care such as drying with a hairdryer after washing, and during heat treatment with a hair iron, thereby protecting hair from damage caused by such daily care and heat treatment.

Claims

1. A composition for suppressing moisture loss from hair, comprising one or more substances selected from the group consisting of acylated hyaluronic acid having an acyl group with 1 to 4 carbon atoms and its salts, and water.

2. The composition according to claim 1, wherein the acylated hyaluronic acid having an acyl group having 1 to 4 carbon atoms is acetylated hyaluronic acid.

3. The composition according to claim 2, wherein the intrinsic viscosity of acetylated hyaluronic acid is 0.5 dL / g to 2.8 dL / g.

4. The composition according to claim 2, wherein the acetylation rate of acetylated hyaluronic acid is 2.6 to 3.9 per repeating unit of hyaluronic acid.

5. The composition according to any one of claims 1 to 4, which is washed off after use.

6. The composition according to any one of claims 1 to 4, wherein the moisture loss of hair is due to heat loss.

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