Hair care product

Abstract

To provide a hair care product which enables suppression of static electricity and snagging upon brushing through application to hair, and also allows improvement of smoothness and handling of hair.SOLUTION: A hair care product comprises cellulose nanofibers, higher fatty acids, and a nonionic surfactant.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hair care product containing cellulose nanofibers and higher fatty acids. [Background technology]

[0002] It is known that with aging, hair becomes thinner, resulting in a loss of overall hair volume, and the scalp becomes dry due to a decrease in sebum secretion, which can result in problems such as static electricity being more likely to occur in hair.In addition, when static electricity occurs in hair, hair strands stick together and swell, making it difficult to manage and causing hairstyles to fall out of place.

[0003] Methods for reducing the effects of static electricity on hair include using hair oil with moisturizing effects and using hair spray to style hair. For example, Patent Document 1 describes obtaining a hair oil by heating an oil agent and modified cellulose fibers as a thickener to about 80°C to make them compatible. It also describes that the obtained hair oil has a moderate viscosity due to the thickening of the oil agent by the modified cellulose fibers, and therefore does not drip easily between the fingers when picked up, providing an excellent feel when used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 186260 Summary of the Invention [Problem to be solved by the invention]

[0005] The hair oil in Patent Document 1 does not contain moisture, so it feels a little heavy on the skin and is not effective enough in reducing the effects of static electricity. In addition, hair care products are required to be smooth to the touch after application, to be less likely to catch on hair when brushed, and to have a pleasant feel to the touch.

[0006] Therefore, the present invention aims to provide a hair care product that, when applied to hair, can suppress the generation of static electricity and snagging during brushing, and can improve the manageability and feel of hair. [Means for solving the problem]

[0007] As a result of extensive investigation, the present inventors have found that the problems can be solved as follows. (1) A hair care product containing cellulose nanofiber, a higher fatty acid, and a nonionic surfactant. (2) The hair care product according to (1), wherein the cellulose nanofibers are anion-modified cellulose nanofibers. (3) The hair care product according to (2), wherein the anion-modified cellulose nanofiber is a carboxylated cellulose nanofiber or a carboxyalkylated cellulose nanofiber. (4) The hair care product according to (3), wherein the anion-modified cellulose nanofibers are carboxymethylated cellulose nanofibers having a degree of carboxymethyl substitution in the range of 0.01 to 0.50. (5) A hair care product according to (1) or (2), further comprising carboxymethyl cellulose. (6) A hair care product according to (1) or (2), wherein the higher fatty acid is one or more selected from the group consisting of oleic acid, linoleic acid, palmitic acid, stearic acid, behenic acid, cis-vaccenic acid, eicosenoic acid, lignoceric acid, and arachidic acid. (7) The hair care product according to (1) or (2), wherein the nonionic surfactant is a carboxylic acid ester. [Effects of the Invention]

[0008] According to the present invention, a hair care product can be provided that, when applied to hair, can suppress the generation of static electricity and snagging during brushing, and can improve the manageability and feel of hair. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a graph showing the results of a load test on samples to which the hair mists of Example 1, Comparative Example 1, Comparative Example 2, and the control were applied. [Figure 2] 1 is a graph showing the results of a static electricity test on samples to which the hair mists of Example 1, Comparative Example 1, Comparative Example 2, and the control were applied. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below, but unless otherwise specified, the expression "AA to BB%" means "not less than AA% and not more than BB%."

[0011] The hair care product of the present invention contains cellulose nanofibers, a higher fatty acid, and a nonionic surfactant.

[0012] (Cellulose nanofiber) In the present invention, cellulose nanofibers (CNFs) are fine fibers with a fiber diameter of approximately 3 to 500 nm, which are obtained by pulp or other cellulose raw materials being refined to the nanometer level. The average fiber diameter and average fiber length of cellulose nanofibers can be obtained by averaging the fiber diameters and fiber lengths obtained from the observation of each fiber using an atomic force microscope (AFM) or a transmission electron microscope (TEM). Cellulose nanofibers can be obtained by applying mechanical force to pulp to refine it, or by defibrating modified cellulose obtained by chemical modification, such as carboxylated cellulose (also called oxidized cellulose), carboxymethylated cellulose, cellulose with a phosphate ester group introduced, or cationized cellulose. The average fiber length and average fiber diameter of fine fibers can be adjusted by chemical modification treatment or defibration treatment.

[0013] The average aspect ratio of the cellulose nanofibers used in the present invention is preferably 10 or more, more preferably 20 or more. There is no particular upper limit, but it is usually 1000 or less. The average aspect ratio can be calculated using the following formula: Aspect ratio = average fiber length / average fiber diameter

[0014] (cellulose raw material) Known cellulose raw materials are derived from plants (for example, wood, bamboo, hemp, jute, kenaf, agricultural waste, cloth, pulp (softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), hardwood bleached kraft pulp (LBKP), softwood unbleached sulfite pulp (NUSP), softwood bleached sulfite pulp (NBSP), thermomechanical pulp (TMP), recycled pulp, waste paper, etc.), animals (for example, ascidians), algae, microorganisms (for example, acetic acid bacteria (Acetobacter)), microbial products, etc.), and any of these can be used in the present invention. Cellulose fibers derived from plants or microorganisms are preferred, and plant-derived cellulose fibers are more preferred.

[0015] (anion-modified) The cellulose nanofibers used in the present invention are preferably anionically modified cellulose nanofibers, which can be obtained by defibrating anionically modified cellulose raw material. Anion modification refers to the introduction of anionic groups into cellulose, specifically the introduction of anionic groups into the pyranose ring by oxidation or substitution reaction. In the present invention, the oxidation reaction refers to a reaction in which the hydroxyl group of the pyranose ring is directly oxidized to a carboxyl group. Furthermore, in the present invention, substitution reaction refers to a reaction in which anionic groups are introduced into the pyranose ring by a substitution reaction other than the oxidation.

[0016] The anion-modified cellulose used as the raw material for anion-modified cellulose nanofibers is one that maintains at least a portion of its fibrous shape even when dispersed in water or a water-soluble organic solvent. If one that does not maintain its fibrous shape (i.e., one that dissolves in a dispersion medium) is used, nanofibers cannot be obtained. "Maintaining at least a portion of the fibrous shape when dispersed" means that a fibrous substance can be observed when a dispersion of the anion-modified cellulose is observed under an electron microscope. Furthermore, anion-modified cellulose that allows observation of a cellulose type I crystal peak when measured by X-ray diffraction is preferred. The crystallinity of the cellulose in the raw material anion-modified cellulose is preferably 50% or more, more preferably 60% or more, for crystalline type I. By adjusting the crystallinity within the above range, it is possible to obtain sufficient crystalline cellulose fibers that do not dissolve even after the fibers are finely divided by defibration. The crystallinity of cellulose type I in the anion-modified cellulose nanofiber is preferably 50 to 90%, more preferably 60 to 80%, and particularly preferably 65 to 75%. If the crystallinity is less than 50%, the dispersion effect will be reduced. The crystallinity of cellulose can be controlled by the crystallinity of the raw cellulose and the degree of anion modification. The crystallinity of anion-modified cellulose and anion-modified CNF can be measured as follows: The sample was placed in a glass cell and measured using an X-ray diffraction measurement device (LabX XRD-6000, manufactured by Shimadzu Corporation). The degree of crystallinity was calculated using the method of Segal et al., where the diffraction intensity at 2θ = 10° to 30° in the X-ray diffraction pattern was used as the baseline, and the degree of crystallinity was calculated using the following formula from the diffraction intensity of the 002 plane at 2θ = 22.6° and the diffraction intensity of the amorphous part at 2θ = 18.5°. Xc=(I002c-Ia) / I002c×100 Xc: Crystallinity of cellulose type I (%) I002c: 2θ=22.6°, diffraction intensity of the 002 plane Ia: 2θ=18.5°, diffraction intensity of the amorphous part.

[0017] (carboxylation) Carboxylated (oxidized) cellulose can be used as anion-modified cellulose. In the present invention, the carboxyl group refers to -COOH (acid type) or -COOM (salt type). Here, M is a metal ion, such as sodium or potassium. Carboxylated cellulose (also called "oxidized cellulose") can be obtained by carboxylating (oxidizing) the above-mentioned cellulose raw material using a known method. Although not particularly limited, the amount of carboxyl groups is preferably 0.6 to 3.0 mmol / g, more preferably 1.0 to 2.0 mmol / g, based on the bone-dry mass of the anion-modified cellulose nanofiber. One example of a carboxylation (oxidation) method is a method in which the cellulose raw material is oxidized in water using an oxidizing agent in the presence of an N-oxyl compound and a compound selected from the group consisting of bromides, iodides, and mixtures thereof. This oxidation reaction selectively oxidizes the primary hydroxyl groups at the C6 position of the glucopyranose ring on the cellulose surface, leaving aldehyde groups and carboxyl groups (-COOH) or carboxylate groups (-COO) on the surface. - The cellulose concentration during the reaction is not particularly limited, but is preferably 5% by mass or less.

[0018] An N-oxyl compound refers to a compound capable of generating a nitroxy radical. Any compound that promotes the target oxidation reaction can be used as the N-oxyl compound. Examples include 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and its derivatives (e.g., 4-hydroxyTEMPO). The amount of the N-oxyl compound used is not particularly limited, as long as it is a catalytic amount capable of oxidizing the cellulose raw material. For example, 0.01 to 10 mmol is preferred, 0.01 to 1 mmol is more preferred, and 0.01 to 0.5 mmol is even more preferred, per 1 g of bone-dry cellulose raw material. The concentration of the N-oxyl compound in the reaction system is preferably about 0.1 to 4 mmol / L.

[0019] Bromides are compounds containing bromine, examples of which include alkali metal bromides that can dissociate and ionize in water. Iodides are compounds containing iodine, examples of which include alkali metal iodides. The amount of bromide or iodide used can be selected within a range that can promote the oxidation reaction. The total amount of bromide and iodide is, for example, preferably 0.1 to 100 mmol, more preferably 0.1 to 10 mmol, and even more preferably 0.5 to 5 mmol, per 1 g of bone-dry cellulose raw material. The modification is a modification due to an oxidation reaction.

[0020] Known oxidizing agents can be used, such as halogens, hypohalous acids, halous acids, perhalogen acids or their salts, halogen oxides, and peroxides. Among these, sodium hypochlorite is preferred because it is inexpensive and environmentally friendly. The appropriate amount of oxidizing agent used is, for example, preferably 0.5 to 500 mmol, more preferably 0.5 to 50 mmol, and even more preferably 2.5 to 25 mmol, per 1 g of bone-dry cellulose raw material. Furthermore, for example, 1 to 40 mol is preferred per 1 mol of the N-oxyl compound.

[0021] The oxidation process of cellulose raw materials can proceed efficiently even under relatively mild conditions. Therefore, the reaction temperature is preferably 4 to 40°C, or may be room temperature, about 15 to 30°C. As the reaction proceeds, carboxyl groups are generated in the cellulose, causing the pH of the reaction solution to decrease. To efficiently proceed with the oxidation reaction, it is preferable to add an alkaline solution such as an aqueous sodium hydroxide solution to the reaction system as needed to maintain the pH of the reaction solution at about 9 to 12, preferably about 10 to 11. Water is preferred as the reaction medium because it is easy to handle and does not easily cause side reactions. The reaction time in the oxidation reaction can be appropriately set depending on the degree of oxidation progress and is usually 0.5 to 6 hours, for example, about 0.5 to 4 hours.

[0022] Alternatively, the oxidation reaction may be carried out in two stages. For example, the oxidized cellulose obtained by filtration after the first stage of the reaction can be oxidized again under the same or different reaction conditions, thereby efficiently introducing carboxyl groups into the cellulose raw material without reaction inhibition by salts produced as by-products in the first stage of the reaction.

[0023] The amount of carboxyl groups in carboxylated cellulose can be adjusted by controlling reaction conditions such as the amount of oxidizing agent added, reaction time, etc. The amount of carboxyl groups in carboxylated cellulose and the amount of carboxyl groups in carboxylated cellulose nanofibers obtained by defibrating the same carboxylated cellulose are usually the same.

[0024] In the present invention, in the oxidized cellulose obtained by the above process, the carboxyl groups introduced into the cellulose raw material are usually in the form of a salt, such as an alkali metal salt such as a sodium salt. Prior to the defibration step, the alkali metal salt of the oxidized cellulose may be substituted with another cationic salt such as a phosphonium salt, an imidazolinium salt, an ammonium salt, or a sulfonium salt. The substitution can be carried out by a known method.

[0025] (carboxyalkylation) Preferred anionic groups include carboxyalkyl groups such as carboxymethyl groups. In the present invention, the carboxyalkyl group refers to -RCOOH (acid type) or -RCOOM (salt type). Here, R is an alkylene group such as a methylene group or an ethylene group, and M is a metal ion. Carboxyalkylated cellulose may be obtained by a known method, or a commercially available product may be used. The degree of carboxyalkyl substitution per anhydroglucose unit of cellulose is preferably 0.50 or less. Furthermore, when the anionic group is a carboxymethyl group, the degree of carboxymethyl substitution is preferably 0.50 or less. If the degree of substitution is greater than 0.50, crystallinity decreases and the proportion of soluble components increases, resulting in loss of nanofiber functionality. Furthermore, the lower limit of the degree of carboxyalkyl substitution is preferably 0.01 or more. Considering operability, the degree of substitution is particularly preferably 0.02 to 0.50, and more preferably 0.10 to 0.40. An example of a method for producing such carboxyalkylated cellulose includes the following steps: The modification is a substitution reaction. The following describes carboxymethylated cellulose as an example. i) mixing the starting material with a solvent and a mercerizing agent, and subjecting the mixture to mercerization at a reaction temperature of 0 to 70°C, preferably 10 to 60°C, for a reaction time of 15 minutes to 8 hours, preferably 30 minutes to 7 hours; ii) Subsequently, a step of adding a carboxymethylating agent in an amount of 0.05 to 10.0 times the moles per glucose residue, and carrying out an etherification reaction at a reaction temperature of 30 to 90°C, preferably 40 to 80°C, for a reaction time of 30 minutes to 10 hours, preferably 1 hour to 4 hours.

[0026] The above-mentioned cellulose raw material can be used as the starting material. As the solvent, 3 to 20 times by mass of water or a lower alcohol, specifically water, methanol, ethanol, N-propyl alcohol, isopropyl alcohol, N-butanol, isobutanol, tertiary butanol, etc., can be used alone or in combination. When a lower alcohol is mixed, the mixing ratio is 60 to 95% by mass. As the mercerizing agent, 0.5 to 20 times by mole of an alkali metal hydroxide, specifically sodium hydroxide or potassium hydroxide, can be used per anhydrous glucose residue of the starting material.

[0027] As mentioned above, the degree of carboxymethyl substitution per glucose unit of cellulose is preferably 0.01 or more and 0.50 or less, more preferably 0.02 or more and 0.50 or less, and even more preferably 0.10 or more and 0.40 or less. Introducing carboxymethyl substituents into cellulose causes electrical repulsion between cellulose molecules. Therefore, cellulose with carboxymethyl substituents introduced can be easily nanofibrillated. Note that if the carboxymethyl substituents per glucose unit are less than 0.02, nanofibrillation may be insufficient. The degree of carboxymethyl substitution in carboxymethylated cellulose and the degree of carboxymethyl substitution in carboxymethylated cellulose nanofibers obtained by fibrillating the same carboxymethylated cellulose are usually the same.

[0028] In the present invention, in the carboxyalkylated cellulose obtained by the above process, the carboxyalkyl group introduced into the cellulose raw material is usually in the form of a salt, such as an alkali metal salt such as a sodium salt. Prior to the defibration process, the alkali metal salt of the carboxyalkylated cellulose may be substituted with another cation salt such as a phosphonium salt, an imidazolinium salt, an ammonium salt, or a sulfonium salt. The substitution can be carried out by a known method.

[0029] In this specification, "carboxymethylated cellulose," a type of anion-modified cellulose used in preparing cellulose nanofibers, refers to cellulose that maintains at least a portion of its fibrous shape when dispersed in water. Therefore, it is distinguished from carboxymethyl cellulose, a type of water-soluble polymer. When an aqueous dispersion of "carboxymethylated cellulose" is observed under an electron microscope, a fibrous substance can be observed. On the other hand, when an aqueous dispersion of carboxymethyl cellulose, a type of water-soluble polymer, is observed, no fibrous substance can be observed. Furthermore, when "carboxymethylated cellulose" is measured by X-ray diffraction, a peak corresponding to cellulose type I crystals can be observed, whereas cellulose type I crystals are not observed in the water-soluble polymer carboxymethyl cellulose.

[0030] (esterification) Esterified cellulose can also be used as anion-modified cellulose. Examples of methods include mixing a powder or aqueous solution of phosphoric acid compound A with a cellulose raw material, or adding an aqueous solution of phosphoric acid compound A to a slurry of the cellulose raw material. Examples of phosphoric acid compound A include phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, polyphosphonic acid, or esters of these. These may be in the form of salts. Among the above, compounds containing phosphoric acid groups are preferred because of their low cost, ease of handling, and the ability to introduce phosphoric acid groups into the cellulose of pulp fibers to improve defibration efficiency. Examples of compounds containing phosphoric acid groups include phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, sodium metaphosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, potassium metaphosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, and ammonium metaphosphate. Phosphate groups can be introduced using one or more of these compounds. Among these, phosphoric acid, sodium salts of phosphoric acid, potassium salts of phosphoric acid, and ammonium salts of phosphoric acid are preferred from the viewpoints of high efficiency of phosphate group introduction, ease of defibration in the defibration step described below, and ease of industrial application. Sodium dihydrogen phosphate and disodium hydrogen phosphate are particularly preferred. Furthermore, it is desirable to use the phosphoric acid compound A as an aqueous solution, as this allows the reaction to proceed uniformly and increases the efficiency of phosphate group introduction. The pH of the aqueous solution of phosphoric acid compound A is preferably 7 or less, as this increases the efficiency of phosphate group introduction, but a pH of 3 to 7 is preferred from the viewpoint of suppressing hydrolysis of pulp fibers.

[0031] The following method can be mentioned as an example of a method for producing phosphated cellulose. A phosphoric acid compound A is added to a suspension of a cellulose raw material having a solids concentration of 0.1 to 10% by mass while stirring, to introduce phosphate groups into the cellulose. When the cellulose raw material is taken as 100 parts by mass, the amount of phosphoric acid compound A added is preferably 0.2 to 500 parts by mass, more preferably 1 to 400 parts by mass, in terms of elemental phosphorus. When the proportion of phosphoric acid compound A is equal to or greater than the lower limit, the yield of fine fibrous cellulose can be further improved. However, when the proportion exceeds the upper limit, the yield improvement effect plateaus, which is undesirable from a cost perspective.

[0032] In addition to the phosphoric acid compound A, a powder or aqueous solution of compound B may be mixed. Compound B is not particularly limited, but is preferably a nitrogen-containing compound exhibiting basicity. "Basicity" here is defined as an aqueous solution exhibiting a pink to red color in the presence of a phenolphthalein indicator, or a pH of greater than 7. The nitrogen-containing compound exhibiting basicity used in the present invention is not particularly limited as long as it exhibits the effects of the present invention, but is preferably a compound having an amino group. Examples include urea, methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, and hexamethylenediamine. Among these, urea is preferred because of its low cost and ease of handling. The amount of compound B added is preferably 2 to 1,000 parts by mass, more preferably 100 to 700 parts by mass, per 100 parts by mass of the solid content of the cellulose raw material. The reaction temperature is preferably 0 to 95°C, more preferably 30 to 90°C. The reaction time is not particularly limited, but is approximately 1 to 600 minutes, more preferably 30 to 480 minutes. When the esterification reaction conditions are within these ranges, it is possible to prevent the cellulose from being excessively esterified and becoming more soluble, resulting in a good yield of phosphated cellulose. After dehydrating the resulting phosphated cellulose suspension, it is preferable to heat-treat it at 100 to 170°C in order to suppress hydrolysis of the cellulose. Furthermore, it is preferable to heat the suspension at 130°C or lower, preferably 110°C or lower, while it contains water, and then, after removing the water, heat-treat it at 100 to 170°C.

[0033] The degree of phosphate substitution per glucose unit of the phosphated cellulose is preferably 0.001 or more and less than 0.40. Introducing phosphate group substituents into cellulose causes electrical repulsion between cellulose units. Therefore, cellulose with introduced phosphate groups can be easily nanofibrillated. If the degree of phosphate substitution per glucose unit is less than 0.001, nanofibrillation is insufficient. On the other hand, if the degree of phosphate substitution per glucose unit is greater than 0.40, the cellulose may swell or dissolve, making it impossible to obtain nanofibers. To achieve efficient fibrillation, the phosphated cellulose raw material obtained above is preferably boiled and then washed with cold water. The modification due to these esterifications is a modification due to a substitution reaction. The degree of phosphate substitution in phosphated cellulose and the degree of phosphate substitution in phosphated cellulose nanofibers obtained by fibrillating the same phosphated cellulose are usually the same.

[0034] In the present invention, in the cellulose phosphate obtained by the above process, the phosphate group introduced into the cellulose raw material is usually in the form of a salt, such as an alkali metal salt such as a sodium salt. Prior to the defibration step, the alkali metal salt of the cellulose phosphate may be substituted with another cationic salt such as a phosphonium salt, an imidazolinium salt, an ammonium salt, or a sulfonium salt. The substitution can be carried out by a known method.

[0035] (defibration) In the present invention, the device for defibrating anionically modified cellulose is not particularly limited. However, it is preferable to apply a strong shear force to the aqueous dispersion of anionically modified cellulose using a device such as a high-speed rotary device, colloid mill device, high-pressure device, roll mill device, or ultrasonic device. In particular, for efficient defibration, it is preferable to apply a pressure of 50 MPa or more to the aqueous dispersion and to use a wet high-pressure or ultra-high-pressure homogenizer capable of applying a strong shear force. The pressure is more preferably 100 MPa or more, and even more preferably 140 MPa or more. Furthermore, prior to defibration and dispersion treatment with a high-pressure homogenizer, the CNF can be pretreated, if necessary, using a known mixing, stirring, emulsifying, or dispersing device such as a high-speed shear mixer. The number of treatments (passes) in the defibration device may be one or two or more times, with two or more being preferred.

[0036] In the dispersion treatment, anionically modified cellulose is usually dispersed in a solvent. The solvent is not particularly limited as long as it can disperse anionically modified cellulose, but examples include water, organic solvents (e.g., hydrophilic organic solvents such as methanol), and mixtures thereof. Since the cellulose raw material is hydrophilic, the solvent is preferably water.

[0037] The solids concentration of the anion-modified cellulose in the dispersion is usually 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass or more. This ensures an appropriate amount of liquid relative to the amount of cellulose fiber raw material, which is efficient. The upper limit is usually 10% by mass or less, preferably 6% by mass or less. This allows fluidity to be maintained.

[0038] Prior to the defibration treatment or dispersion treatment, a pretreatment may be carried out as necessary. The pretreatment may be carried out using a mixing, stirring, emulsifying, or dispersing device such as a high-speed shear mixer.

[0039] When the anion-modified cellulose nanofibers obtained through the defibration treatment are in the salt form, they may be used as they are, or may be converted into the acid form by acid treatment using a mineral acid, a method using a cation exchange resin, etc. Furthermore, they may be made hydrophobic by a method using a cationic additive.

[0040] The cellulose nanofibers used in the present invention may be an aqueous dispersion of anion-modified cellulose nanofibers obtained through the above-mentioned defibration treatment, or may be a powder obtained by drying and pulverizing the cellulose nanofibers, or may be redispersed in an aqueous solvent such as water.

[0041] The cellulose nanofibers used in the present invention preferably have a Brookfield viscosity of 100 to 5000 mPa·s, more preferably 300 to 3000 mPa·s, under conditions of a solids concentration of 1%, 60 rpm, and 25°C.

[0042] (higher fatty acids) In this specification, higher fatty acids refer to fatty acids having 12 or more carbon atoms.

[0043] The higher fatty acids used in the present invention may be either straight-chain or branched fatty acids, and may be either saturated or unsaturated fatty acids. Examples include lauric acid, myristic acid, pentadecylic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid, eleostearic acid, arachidic acid, mead acid, arachidonic acid, behenic acid, isopalmitic acid, isostearic acid, isoarachidic acid, eicosenoic acid, lignoceric acid, and arachidic acid, and preferably include oleic acid, linoleic acid, palmitic acid, stearic acid, behenic acid, cis-vaccenic acid, eicosenoic acid, lignoceric acid, and arachidic acid.

[0044] These higher fatty acids may be used alone or in combination of two or more.

[0045] From the viewpoint of having a positive effect on improving the skin barrier function, the higher fatty acids used in the present invention preferably contain higher fatty acids derived from sunflower seed oil, and more preferably consist solely of higher fatty acids derived from sunflower seed oil, such as oleic acid, linoleic acid, palmitic acid, stearic acid, behenic acid, cis-vaccenic acid, eicosenoic acid, lignoceric acid, arachidic acid, myristic acid, palmitoleic acid, and linolenic acid.

[0046] The higher fatty acid used in the present invention is a main component of a composition obtained by treating sunflower seed oil with an enzyme, and preferably contains oleic acid and linoleic acid as essential components from the viewpoint of improving skin barrier function. When the total amount of higher fatty acids contained in the hair care product is taken as 100% by mass, the total amount of oleic acid and linoleic acid is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more. Furthermore, it is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less.

[0047] The method for producing the higher fatty acids used in the present invention is not particularly limited. For example, the higher fatty acids can be obtained by reacting sunflower seed oil with lipase, a type of lipolytic enzyme, in water at a temperature of 30 to 40°C and a humidity of 40 to 70%, while stirring at predetermined intervals, sterilizing the resulting mixture by heating, freezing it, and thawing and filtering the separated oil layer.

[0048] (nonionic surfactant) Examples of the nonionic surfactant used in the present invention include glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, etc. Among these, it is preferable to use carboxylic acid esters such as glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene glycerin fatty acid esters, and polyoxyethylene sorbitol fatty acid esters.

[0049] Polyglycerol fatty acid esters are esters of fatty acids and polyglycerol. In polyglycerol fatty acid esters, the number of ester bonds (the number of fatty acids bonded per polyglycerol molecule) is, for example, 1 to 10. The number of carbon atoms of the fatty acids constituting the polyglycerol fatty acid ester is, for example, 6 to 24. The degree of polymerization of the polyglycerol constituting the polyglycerol fatty acid ester is, for example, 2 to 10, preferably 4 to 10, and more preferably 6 to 10. Specific examples of polyglycerin fatty acid esters include polyglyceryl-2 laurate (diglyceryl laurate), polyglyceryl-4 laurate (tetraglyceryl laurate), polyglyceryl-5 laurate (pentaglyceryl laurate), polyglyceryl-6 laurate (hexaglyceryl laurate), polyglyceryl-10 laurate (decaglyceryl laurate), polyglyceryl-2 stearate (diglyceryl monostearate), polyglyceryl-2 oleate (diglyceryl monooleate), polyglyceryl-4 oleate (tetraglyceryl monooleate), polyglyceryl-10 oleate (decaglyceryl monooleate), and polyglyceryl-5 trioleate (trioleate). Examples of the glyceryl stearate include pentaglyceryl phosphate, polyglyceryl-10 trioleate (decaglyceryl trioleate), polyglyceryl-10 palmitate (decaglyceryl monopalmitate), polyglyceryl-10 myristate, polyglyceryl-2 isostearate, polyglyceryl-10 isostearate, polyglyceryl-2 triisostearate, polyglyceryl-4 stearate, polyglyceryl-6 tristearate, polyglyceryl-10 pentastearate, polyglyceryl-10 pentahydroxystearate, polyglyceryl-10 pentaisostearate, polyglyceryl-10 pentaoleate, polyglyceryl-6 polyricinoleate, and polyglyceryl-10 polyricinoleate.

[0050] These nonionic surfactants may be used alone or in combination of two or more.

[0051] Among these nonionic surfactants, it is preferable to use polyglycerol fatty acid esters, which are carboxylic acid esters, and examples thereof include polyglycerol fatty acid esters in which the degree of polymerization of polyglycerol is preferably 4 to 10, the number of ester bonds is preferably 1 to 5, and the number of carbon atoms of the fatty acid constituting the polyglycerol fatty acid ester is preferably 8 to 22. Among these, it is preferable to use polyglyceryl-4 laurate (tetraglyceryl laurate), polyglyceryl-6 laurate (hexaglyceryl laurate), and polyglyceryl-10 laurate (decaglyceryl laurate), with polyglyceryl-4 laurate (tetraglyceryl laurate) and polyglyceryl-6 laurate (hexaglyceryl laurate) being particularly preferred.

[0052] (Hair care products) The hair care product of the present invention contains cellulose nanofibers, higher fatty acids, and nonionic surfactants as essential ingredients. From the viewpoint of effectively suppressing static electricity, the hair care product of the present invention is preferably a product in which the above essential ingredients are dispersed in an aqueous solvent. The aqueous solvent that can be used in the present invention is preferably water, a water-soluble organic solvent, or a mixture thereof. Considering the dispersibility of chemically modified pulp and CNF, the aqueous solvent is preferably water or a mixture of water and a water-soluble organic solvent. Furthermore, from the viewpoints of cost, environmental friendliness, and safety, it is more preferable to use water as the aqueous solvent.

[0053] The water-soluble organic solvent is an organic solvent that dissolves in water. Examples include methanol, ethanol, 2-propanol, butanol, glycerin, acetone, methyl ethyl ketone, 1,4-dioxane, N-methyl-2-pyrrolidone, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, acetonitrile, and combinations thereof. Among these, lower alcohols having 1 to 4 carbon atoms, such as methanol, ethanol, and 2-propanol, are preferred. From the viewpoints of safety and availability, methanol and ethanol are more preferred, and ethanol is even more preferred. The amount of the water-soluble organic solvent in the mixed solvent is preferably 10% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more. There is no upper limit to this amount, but it is preferably 95% by mass or less, more preferably 90% by mass or less. Furthermore, the aqueous solvent may contain a non-water-soluble organic solvent to the extent that the effects of the invention are not impaired.

[0054] In the hair care product of the present invention, the blending ratio of each component is not particularly limited. However, the solids concentration of cellulose nanofibers in the hair care product is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.5 to 1% by mass, from the viewpoint of effectively suppressing static electricity. Furthermore, the content of higher fatty acids in the hair care product is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.5 to 1% by mass, from the viewpoint of effectively suppressing static electricity. Furthermore, the content of nonionic surfactants in the hair care product is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, and even more preferably 1.0 to 3.5% by mass, from the viewpoint of effectively suppressing static electricity. Furthermore, from the viewpoint of effectively suppressing static electricity, the solids content of CNF is preferably 1 to 500 parts by mass, more preferably 10 to 200 parts by mass, and even more preferably 30 to 100 parts by mass per 100 parts by mass of higher fatty acids. From the viewpoint of effectively suppressing static electricity, the nonionic surfactant is preferably blended in an amount of 10 to 1,000 parts by mass, more preferably 100 to 800 parts by mass, and even more preferably 200 to 600 parts by mass, per 100 parts by mass of CNF. From the viewpoint of effectively suppressing static electricity, the content of the aqueous solvent in the hair care product is preferably 40 to 99.9% by mass, more preferably 60 to 99% by mass, and even more preferably 70 to 98% by mass.

[0055] The hair care product of the present invention may also contain a dispersant other than CNF, as long as the effect of the present invention is not impaired. Examples of dispersants other than CNF include water-soluble polymers, acrylic dispersants, polycarboxylic acid dispersants, silicone materials, and silane coupling agents.

[0056] Water-soluble polymers include cellulose derivatives (carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, ethylcellulose), xanthan gum, xyloglucan, dextrin, dextran, carrageenan, locust bean gum, alginic acid, alginate, pullulan, starch, potato starch, arrowroot flour, cationic starch, phosphorylated starch, corn starch, gum arabic, gellan gum, polydextrose, pectin, chitin, water-soluble chitin, chitosan, casein, albumin, soy protein lysate, peptone, polyvinyl alcohol, poly Examples of suitable polymers include acrylamide, sodium polyacrylate, polyvinylpyrrolidone, polyvinyl acetate, polyamino acids, polylactic acid, polymalic acid, polyglycerin, latex, rosin-based sizing agents, petroleum resin-based sizing agents, urea resins, melamine resins, epoxy resins, polyamide resins, polyamide-polyamine resins, polyethyleneimine, polyamines, vegetable gums, polyethylene oxide, hydrophilic crosslinked polymers, polyacrylates, starch-polyacrylic acid copolymers, tamarind gum, guar gum, and colloidal silica, as well as mixtures of one or more thereof. Among these, carboxymethyl cellulose is preferred from the viewpoint of improving dispersibility.

[0057] (Hair care product manufacturing method) The method for producing the hair care product of the present invention is not particularly limited, and for example, when producing a hair mist, it can be obtained by mixing and stirring an aqueous solvent, cellulose nanofibers, a higher fatty acid, and a nonionic surfactant. The hair care product of the present invention can be obtained by stirring and mixing using conventional devices and means, and the temperature conditions, etc. are not particularly limited.

[0058] The hair care product of the present invention contains cellulose nanofibers, higher fatty acids, preferably higher fatty acids derived from sunflower seed oil, and a nonionic surfactant, and therefore exhibits a coating effect when applied to hair, suppressing static electricity generation and snagging during brushing. This protects hair from friction and static electricity. Furthermore, the excellent hair moisturizing effect also suppresses static electricity generation, further improving hair manageability and feel. Therefore, this hair care product can be suitably used in hair mists, hair sprays, hair gels, water greases, setting lotions, color lotions, hair tonics, hair liquids, and the like.

[0059] In addition to the dispersants exemplified above, the hair care product of the present invention may also contain ultraviolet absorbers, oils other than higher fatty acids, surfactants other than nonionic surfactants, preservatives, fragrances, moisturizers, salts, antioxidants, chelating agents, neutralizing agents, pH adjusters, and the like, as long as the effects of the present invention are not impaired. [Example]

[0060] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0061] (Production Example 1) (Production of carboxymethylated cellulose nanofibers) A 5-L twin-screw kneader with the rotation speed adjusted to 100 rpm was charged with 1,089 parts of isopropanol (IPA) and a solution of 31 parts of sodium hydroxide in 121 parts of water. 200 parts of hardwood pulp (LBKP, manufactured by Nippon Paper Industries Co., Ltd.) (dry mass after drying at 100°C for 60 minutes) was then added. The mixture was stirred and mixed at 30°C for 60 minutes to prepare mercerized cellulose. Further stirring was continued, and 117 parts of sodium monochloroacetate was added. After stirring at 30°C for 30 minutes, the mixture was heated to 70°C over 30 minutes and allowed to undergo a carboxymethylation reaction at 70°C for 60 minutes. The proportion of water in the reaction medium during the mercerization and carboxymethylation reactions was 10% by mass. After completion of the reaction, the mixture was neutralized, washed with 65% aqueous methanol, deliquored, dried, and pulverized to obtain a sodium salt of carboxymethylated cellulose with a carboxymethyl substitution degree of 0.27 and a crystallinity of cellulose type I of 64%. The method for measuring the crystallinity of cellulose type I is as described above. The resulting sodium salt of carboxymethyl cellulose was dispersed in water to form a 1% (w / v) aqueous dispersion. This was then processed three times in a high-pressure homogenizer at 150 MPa to obtain a dispersion of carboxymethyl cellulose nanofibers. The resulting carboxymethyl cellulose nanofibers had an average fiber diameter of 3.2 nm and an aspect ratio of 40.

[0062] The resulting carboxymethylated cellulose nanofibers were dispersed in water to a solids content of 0.7% by mass. Carboxymethyl cellulose (hereinafter sometimes referred to as "CMC") (Nippon Paper Industries Co., Ltd., product name: FS350HC-4, viscosity (1% by mass, 25°C, 60 rpm) approximately 3000 mPa·s, degree of carboxymethyl substitution approximately 0.90) was added at 40% by mass relative to the carboxymethyl cellulose nanofibers (i.e., 40 parts by mass of carboxymethyl cellulose per 100 parts by mass of carboxymethyl cellulose nanofiber solids). The mixture was stirred for 60 minutes in a TK homomixer (12,000 rpm). The resulting aqueous dispersion of CMC-containing carboxymethylated cellulose nanofibers was adjusted to pH 9 with the addition of aqueous sodium hydroxide. The resulting aqueous dispersion was then dehydrated and dried in a drum dryer to obtain a dry solid. The resulting solid was then pulverized and classified using a 30-mesh mesh to obtain a powder of CMC-containing carboxymethylated cellulose nanofibers.

[0063] (Method for measuring the degree of carboxymethyl substitution per glucose unit) Approximately 2.0 g of carboxymethylated cellulose fiber (bone dry) was weighed and placed in a 300 mL Erlenmeyer flask with a stopper. 100 mL of a solution prepared by adding 10 mL of concentrated nitric acid to 90 mL of methanol was added and the mixture was shaken for 3 hours to convert the carboxymethylated cellulose salt (carboxymethylated cellulose) into hydrogenated carboxymethylated cellulose. 1.5 to 2.0 g of hydrogenated carboxymethylated cellulose (bone dry) was weighed and placed in a 300 mL Erlenmeyer flask with a stopper. The hydrogenated carboxymethylated cellulose was moistened with 15 mL of 80% methanol, 100 mL of 0.1 N NaOH was added, and the mixture was shaken at room temperature for 3 hours. Excess NaOH was back-titrated with 0.1 N H2SO4 using phenolphthalein as an indicator. The degree of carboxymethyl substitution (DS) was calculated using the following formula: A = [(100 × F' - (0.1N H2SO4) (mL) × F) × 0.1] / (bone-dry mass of hydrogenated carboxymethyl cellulose (g)) DS=0.162×A / (1-0.058×A) A: Amount of 1N NaOH (mL) required to neutralize 1 g of hydrogenated carboxymethyl cellulose F: Factor of 0.1N H2SO4 F': Factor of 0.1N NaOH

[0064] (Production Example 2) (Production of sunflower seed oil fatty acid-containing composition) 120 milliliters of sunflower seed oil, 80 milliliters of purified water, and 7.5 milligrams of lipase (a hydrolytic enzyme) were prepared and mixed. Microbial lipase obtained by culturing bacteria was used as the lipase. The resulting mixture was then left to stand for 7 days in a room at a temperature of 30-40°C and a humidity of 60%. During this 7-day period, the mixture was stirred for approximately 5 minutes using a hand mixer (3000 RPM) approximately once every 24 hours until the mixture stabilized in an emulsion state. The hand mixer was then moved up and down to mix the mixture until the separated oil and water layers disappeared.

[0065] After 7 days, the mixture was sterilized by heating at about 90°C for 1 second or more to inactivate the enzyme and thereby stop the reaction.

[0066] The mixture was frozen, and when the mixture became two layers of oil and water, hot air at about 120°C was applied to the upper oil layer to thaw and remove the oil. After that, it was filtered, and repeated freezing, separation, and thawing was performed until it became transparent, to obtain a sunflower seed oil fatty acid-containing composition.

[0067] The fatty acid-containing composition thus obtained was analyzed for composition by high performance liquid chromatography. (Analysis conditions) Equipment: High-performance liquid chromatograph (Shimadzu Corporation) Mobile phase: A liquid ultrapure water, B liquid acetonitrile Gradient conditions 0~8 minutes 85% B solution 8~30 minutes 85~95% B solution Column: TSKgel Octyl-80Ts (Tosoh Corporation, 150 mm x 4.6 mm) Sample injection volume: 10 μL Temperature: 40℃ Measurement wavelength: Fluorescence detection Excitation wavelength 365 nm Fluorescence wavelength 412 nm Flow rate: 1.0 mL / min

[0068] The analytical results of the content ratio of fatty acids in the fatty acid-containing composition are shown in Table 1. The total amount of fatty acids in the fatty acid-containing composition (100 g) was 89.8 g. [Table 1]

[0069] Example 1 (Hair mist manufacturing) A hair mist was obtained by adding 0.5 g of the powder of CMC-containing carboxymethylated cellulose nanofiber produced in Production Example 1, 2 g of a nonionic surfactant (trade name: PolyAquol LW, manufactured by Innovacos, containing a mixture of polyglyceryl-4 laurate and polyglyceryl-6 laurate), and 1 mL of the sunflower seed oil fatty acid-containing composition produced in Production Example 2 to 96.5 mL of purified water and mixing them.

[0070] (Comparative Example 1) A hair mist was obtained in the same manner as in Example 1, except that an oil (trade name: FineNeo-iPSE, manufactured by Nippon Fine Chemicals, containing diisopropyl sebacate) was used instead of the nonionic surfactant.

[0071] (Comparative Example 2) A hair mist was obtained by adding 0.5 g of the powder of CMC-containing carboxymethylated cellulose nanofibers produced in Production Example 1 to 99.5 mL of purified water and mixing.

[0072] (Load test) The hair mists obtained in the examples and comparative examples were sprayed twice onto a bundle of hair, lightly combed, and then left for 3 minutes, and then dried using a hair dryer to prepare a combing tester sample. As a control, a sample using only purified water instead of the hair mists was also prepared. The obtained samples were measured using a combing tester (model: SK-3A, manufactured by Techno Hashimoto) to measure the amount of strain (load) when a comb was passed through the hair strands. Three samples were used for each test, and the obtained values ​​were averaged. The amount of strain (load) was measured in advance using the combing tester for the hair strands before spraying with hair mist (three samples for each test). The amount of strain obtained for each combing tester sample, assuming the amount of strain on the hair strand before spraying to be 1, is shown in Figure 1 as the results of the load test. A value smaller than 1 indicates less strain than before spraying with hair mist.

[0073] According to Figure 1, when the hair mist of Example 1 was used, the load (amount of catching) when combing was smaller than when the hair mists of Comparative Examples 1 and 2 were used, and it was found that the combing was easier.

[0074] (Static electricity test) Combing tester samples were prepared in the same manner as in the load test described above, and the amount of static electricity was measured using the combing tester. Three samples were prepared for each test, and the obtained values ​​were averaged. The amount of static electricity was measured in advance using the combing tester for hair bundles before spraying with hair mist (three samples for each test). The amount of static electricity obtained for each combing tester sample, assuming the amount of static electricity on the hair bundle before spraying to be 1, is shown in Figure 2 as the results of the static electricity test. A value smaller than 1 indicates a lower amount of static electricity than before spraying with hair mist.

[0075] 2, it was found that when the hair mist of Example 1 was used, the amount of static electricity generated when combing was less than when the hair mists of Comparative Examples 1 and 2 were used.

[0076] (Tactile test) The feel test was conducted by preparing hair bundle samples similar to the combing tester samples, and having 20 panelists touch these hair bundles. This test method aims to evaluate the feel and usability of the product when touched using human senses. In the feel test, the panelists were asked to comment on the feel of the hair bundle samples obtained using four types of hair mists: Example 1, Comparative Examples 1 and 2, and the control, thereby clarifying the feel characteristics of each hair bundle sample. The results of the combined comments are listed below.

[0077] Example 1 and Comparative Example 1 are samples containing a nonionic surfactant or oil, CNF, purified water, and a sunflower seed oil fatty acid-containing composition, and both exhibited a moist and thick feel. However, Example 1 was evaluated as being softer and more slippery than Comparative Example 2, and had a softer impression than Comparative Example 1. On the other hand, Comparative Example 1 was slightly harder than Example 1, and had the impression of leaving a dry finish.

[0078] Comparative Example 2 is a sample containing only CNF and purified water, and although there were fewer comments about the feel compared to Example 1 and Comparative Example 1, it was suggested that the feel was somewhat thin.

[0079] Finally, the control sample contained only purified water and had a milder overall feel, likely due to the lack of cosmetic ingredients compared to the other samples.

Claims

1. A hair care product containing cellulose nanofiber, a higher fatty acid, and a nonionic surfactant.

2. The hair care product according to claim 1, wherein the cellulose nanofibers are anionically modified cellulose nanofibers.

3. The hair care product according to claim 2, wherein the anionically modified cellulose nanofiber is a carboxylated cellulose nanofiber or a carboxyalkylated cellulose nanofiber.

4. 4. The hair care product according to claim 3, wherein the anion-modified cellulose nanofibers are carboxymethylated cellulose nanofibers having a degree of carboxymethyl substitution in the range of 0.01 to 0.

50.

5. The hair care product according to claim 1 or 2, further comprising carboxymethyl cellulose.

6. 3. The hair care product according to claim 1, wherein the higher fatty acid is at least one selected from the group consisting of oleic acid, linoleic acid, palmitic acid, stearic acid, behenic acid, cis-vaccenic acid, eicosenoic acid, lignoceric acid, and arachidic acid.

7. 3. The hair care product according to claim 1, wherein the nonionic surfactant is a carboxylic acid ester.

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