JP6805316B1 - Thickeners and cosmetics for cosmetics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve salt resistance in a thickener for cosmetics containing a carboxyvinyl polymer, an alkyl-modified carboxyvinyl polymer or a salt thereof. A thickener for cosmetics according to an embodiment contains the following components (A) and (B), and (with respect to 100 parts by mass of the total amount of the components (A) and (B)). A) Contains 0.1 parts by mass or more and less than 25 parts by mass. Component (A): Cellulose fiber having a maximum fiber diameter of 1000 nm or less and a number average fiber diameter of 2 to 150 nm, and having a cellulose I-type crystal structure. (B) Ingredient: At least one selected from the group consisting of carboxyvinyl polymers, alkyl-modified carboxyvinyl polymers and salts thereof. [Selection diagram] None

Description

The present invention relates to a thickener for cosmetics and a cosmetic containing the same.

Conventionally, for cosmetics having a creamy, gelling, milky or liquid dosage form, a composition in which a polymer material or the like is mixed with a dispersion medium such as water, alcohol or oil has been used. The above-mentioned polymer material is used for the purpose of imparting shape-retaining performance (shape-retaining property) for maintaining thickening and dispersion stability, and is, for example, a carboxyvinyl polymer, an alkyl-modified carboxyvinyl polymer, or them. Salt is used (see, for example, Patent Document 1).

The above-mentioned carboxyvinyl polymers and the like are characterized by excellent viscosity and a non-sticky feel, and are general-purpose thickeners used in cosmetics and the like, but have low salt resistance. Therefore, for example, the concentration of salt contained in the blending of cosmetics is limited, so that the degree of freedom of blending is low, and the viscosity is significantly reduced when sodium chloride derived from sweat is attached to the skin. It may end up.

JP-A-2017-128524

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve salt resistance in a thickener for cosmetics containing a carboxyvinyl polymer, an alkyl-modified carboxyvinyl polymer, or a salt thereof. To do.

The thickener for cosmetics according to the present invention contains the following components (A) and (B), and the component (A) is added to 100 parts by mass of the total amount of the components (A) and (B). It contains 0.3 parts by mass or more and 16 parts by mass or less (however, except when it contains an amphoteric metal) .
Component (A): Cellulose fiber having a maximum fiber diameter of 1000 nm or less and a number average fiber diameter of 2 to 150 nm, and having a cellulose I-type crystal structure.
(B) Ingredient: At least one selected from the group consisting of carboxyvinyl polymers, alkyl-modified carboxyvinyl polymers and salts thereof.
The cosmetic according to the present invention contains the thickener for cosmetics.

According to the present invention, it is possible to provide a thickener for cosmetics having improved salt resistance by using the cellulose fiber of the above component (A) together with the carboxyvinyl polymer, the alkyl-modified carboxyvinyl polymer and the like. Further, by reducing the ratio of the cellulose fibers of the component (A), it is possible to suppress a decrease in the viscosity recovery rate due to the blending of the cellulose fibers.

The cosmetic thickener according to the present embodiment is selected from the group consisting of a specific cellulose fiber as a component (A), a carboxyvinyl polymer as a component (B), an alkyl-modified carboxyvinyl polymer, and salts thereof. The component (A) and the component (B) are contained in an amount of 0.1 part by mass or more and less than 25 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B).

By adding the component (A) in a small amount to the component (B) in this way, the salt resistance can be significantly improved without impairing the excellent viscosity and usability of the component (B). In addition, the following effects are also achieved. The viscosity of the aqueous solution containing the component (B) decreases significantly when a force is applied, but since it has a high viscosity property, it has the property that the viscosity recovers as soon as the force is stopped, that is, the viscosity recovery rate is high. Therefore, when the component (B) is used, in a cosmetic product in which the container is shaken and stirred before use, the viscosity does not change significantly before and after stirring, and a cosmetic product that can be used with high viscosity can be prepared. .. If a large amount of the component (A) is combined with the component (B) having such performance, the recovery of the viscosity immediately after shaking and stirring the container is delayed, that is, the viscosity recovery rate is lowered. On the other hand, according to the present embodiment, by setting the ratio of the component (A) as described above, it is possible to significantly improve the salt resistance while suppressing the decrease in the viscosity recovery rate.

[(A) component]
The cellulose fiber of the component (A) has a cellulose type I crystal structure, and has a maximum fiber diameter of 1000 nm or less and a number average fiber diameter of 2 to 150 nm. Fine fibrous cellulose (also referred to as cellulose nanofiber). To be used.) Is used.

Cellulose type I crystals are in the crystalline form of natural cellulose, and by having a type I crystal structure, the cellulose fibers are insoluble in water and are therefore water dispersible. Having a cellulose I-type crystal structure is a typical peak at two positions in the diffraction profile obtained by wide-angle X-ray diffraction image measurement, near 2θ = 14 ° to 17 ° and around 2θ = 22 ° to 23 °. It can be identified by having.

When the maximum fiber diameter of the cellulose fiber is 1000 nm or less, the sedimentation of the cellulose fiber in water can be suppressed, and the function of blending the cellulose fiber can be exhibited. The maximum fiber diameter is preferably 500 nm or less, more preferably 100 nm or less.

When the number average fiber diameter of the cellulose fibers is 150 nm or less, the sedimentation of the cellulose fibers in water can be suppressed, and the function of blending the cellulose fibers can be exhibited. The number average fiber diameter is preferably 3 nm or more, and may be 4 nm or more. The number average fiber diameter is preferably 100 nm or less, more preferably 80 nm or less, and further preferably 30 nm or less.

The maximum fiber diameter and the number average fiber diameter of the cellulose fibers can be measured as follows. An aqueous dispersion of cellulose fibers having a solid content of 0.05 to 0.1% by mass was prepared, and the aqueous dispersion was cast on a hydrophilized carbon film-coated grid to perform a transmission electron microscope (transmission electron microscope). It is used as an observation sample of TEM). When fibers having a large fiber diameter are included, a scanning electron microscope (SEM) image of the surface cast on the glass may be observed. Further, the observation sample may be negatively stained with, for example, 2% by mass uranyl acetate. Then, observation is performed using an electron microscope image at a magnification of 5000 times, 10000 times, or 50,000 times depending on the size of the constituent fibers. At that time, an axis having an arbitrary vertical and horizontal image width is assumed in the obtained image, and the sample and observation conditions (magnification, etc.) are adjusted so that 20 or more fibers intersect the axis. Then, after obtaining an observation image satisfying this condition, two random axes in each of the vertical and horizontal directions are drawn with respect to this image, and the fiber diameters of the fibers intersecting the axes are visually read. In this way, images of at least three non-overlapping surface portions are taken with an electron microscope and the value of the fiber diameter of the fibers intersecting each of the two axes is read (thus, at least 20 fibers × 2 × 3 = 120). Information on the fiber diameter of the book can be obtained). The arithmetic mean of the fiber diameters thus obtained is defined as the number average fiber diameter, and the maximum value of these fiber diameters is defined as the maximum fiber diameter.

The average aspect ratio of the cellulose fibers of the component (A) is not particularly limited, but is preferably 50 or more and 1000 or less, more preferably 50 or more and 500 or less, and further preferably 50 or more and 300 or less. The average aspect ratio can be measured as follows. The number average fiber diameter is calculated according to the method described above. In addition, the number average fiber length of the fine fibrous cellulose is calculated from the same observation image. Specifically, at least 10 fibers from the start point to the end point (fiber length) are visually read. For branched fibers, the length of the longest portion of the fiber is defined as the fiber length. The arithmetic mean of the fiber lengths thus obtained is calculated and used as the number average fiber length. Using these values, the average aspect ratio is calculated according to the following formula.
Average aspect ratio = number average fiber length (nm) / number average fiber diameter (nm)

As the cellulose fiber of the component (A), those having an anionic functional group are preferable. The cellulose fiber having an anionic functional group is not particularly limited, and examples thereof include oxidized cellulose fiber, carboxymethylated cellulose fiber, phosphorylated cellulose fiber, subphosphorylated cellulose fiber, and sulfated cellulose fiber.

Examples of the anionic functional group include at least one selected from the group consisting of a carboxy group, a phosphoric acid group, a phosphorous acid group, and a sulfate group. In the present specification, the carboxy group is a concept including not only an acid type (-COOH) but also a salt type, that is, a carboxylic acid base (-COOX, where X is a cation forming a salt with a carboxylic acid). Acid type and salt type may be mixed. Similarly, the phosphoric acid group, the phosphorous acid group, and the sulfate group are concepts that include not only the acid type but also the salt type, and the acid type and the salt type may be mixed. The salt is not particularly limited, and for example, an alkali metal salt such as sodium salt and potassium salt, an alkaline earth metal salt such as magnesium salt and calcium salt, an onium salt such as ammonium salt and phosphonium salt, a primary amine, and 2 Examples thereof include amine salts such as primary amines and tertiary amines.

The amount of the anionic functional group in the cellulose fiber of the component (A) is 0.6 to 2.3 mmol / g per dry mass of the cellulose fiber from the viewpoint of dispersion stability in water and usability as a cosmetic. Is preferable, and more preferably 1.0 to 2.0 mmol / g. Regarding the amount of anionic functional groups, for example, in the case of a carboxy group, 60 mL of a cellulose fiber-containing slurry prepared to a concentration of 0.1 to 1% by mass was prepared, and the pH was adjusted to about 2. by a 0.1 mol / L hydrochloric acid aqueous solution. After setting to 5, 0.05 mol / L aqueous sodium hydroxide solution was added dropwise, the electrical conductivity was measured, and the pH was continued until the pH reached about 11, in the neutralization step of a weak acid in which the change in electrical conductivity was gradual. From the amount of sodium hydroxide (V) consumed, it can be calculated according to the following formula. Other anionic functional groups may also be measured by a known method.
Amount of carboxy group (mmol / g) = V (mL) x [0.05 / mass of cellulose fiber (g)]

The cellulose fiber of the component (A) preferably has a carboxy group as an anionic functional group from the viewpoint of salt resistance. Examples of the cellulose fiber containing a carboxy group include an oxidized cellulose fiber obtained by oxidizing the hydroxyl group of a glucose unit in a cellulose molecule and a carboxymethylated cellulose fiber obtained by carboxymethylating the hydroxyl group of a glucose unit in a cellulose molecule. Can be mentioned.

In the cellulose oxide fiber, the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule is selectively oxidized and modified to a carboxy group, whereby the ratio of the carboxy group is 0.6 to 2.3 mmol / g ( More preferably, it is 1.0 to 2.0 mmol / g). Oxidized cellulose fibers are obtained by oxidizing natural cellulose such as wood pulp with an oxidizer in the presence of an N-oxyl compound and defibrating (refining) the fibers. As the N-oxyl compound, a compound having a nitroxy radical generally used as an oxidation catalyst is used, for example, a piperidine nitroxyoxy radical, and particularly 2,2,6,6-tetramethylpiperidinooxy radical (TEMPO). ) Or 4-acetamide-TEMPO is preferred. Cellulose fibers oxidized by TEMPO are generally referred to as TEMPO oxidized cellulose nanofibers (TOCN). The cellulose oxide fiber may have an aldehyde group or a ketone group together with the carboxy group.

The cellulose fiber of the component (A) may be obtained by performing a defibration treatment. The defibration treatment may be carried out after the anionic functional group is introduced, or may be carried out before the introduction. In the defibration treatment, for example, a homomixer under high-speed rotation, a high-pressure homogenizer, an ultrasonic disperser, a beater, a disc-type refiner, a conical-type refiner, a double-disc type refiner, a grinder, or the like is used to disperse cellulose fibers in water. This can be done by treating the liquid, whereby an aqueous dispersion of fine fibrous cellulose fibers can be obtained.

[(B) component]
The component (B) is a thickening accelerator, and at least one selected from the group consisting of a carboxyvinyl polymer, an alkyl-modified carboxyvinyl polymer and a salt thereof is used.

The carboxyvinyl polymer is a water-soluble vinyl polymer having a carboxy group, and examples thereof include a polymer of acrylic acid and / or methacrylic acid, and a polymer of acrylic is preferable. Further, a polymer of acrylic acid and / or methacrylic acid may be used as a main chain and crosslinked with allylsucrose or pentaerythritol. Examples of commercially available carboxyvinyl polymers include Carbopol Ultrez 30, Carbopol 940, Carbopol 941, Carbopol 980, Carbopol 981 (all manufactured by Lubrizol), AQUAPEC HV-801EG-300, AQPEC HV-801EG-300 -501E (above, manufactured by Sumitomo Seika Co., Ltd.) and the like.

The alkyl-modified carboxyvinyl polymer is a copolymer of (meth) acrylic acid and alkyl (meth) acrylic acid. Here, the (meth) acrylic acid means acrylic acid and / or methacrylic acid, and the (meth) alkyl acrylate means an alkyl acrylate and / or an alkyl methacrylate. It is preferably a copolymer of acrylic acid and an alkyl (meth) acrylate, more preferably a copolymer of acrylic acid and an alkyl (meth) acrylate having an alkyl group having 10 to 30 carbon atoms, for example, INCI. Name: Acrylate / C10-30 alkyl acrylate crosspolymer may be used. Examples of commercially available alkyl-modified carboxyvinyl polymers include Carbopol Ultrez 20, Carbopol Ultrez 21, Carbopol 1342, PEMULEN TR-1 (all manufactured by Lubrizol), AQUAPEC HV-801ERK, and AQUAPEC HV-80. (The above is manufactured by Sumitomo Seika Co., Ltd.).

The carboxyvinyl polymer and the alkyl-modified carboxyvinyl polymer are preferably present as salts by neutralization with a base. Examples of these salts include alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as calcium and magnesium, organic amine salts such as ammonium salt, triethanolamine salt and triethylamine salt, lysine salt and arginine. Examples thereof include a basic amino acid salt such as a salt, or a combination of two or more of these, and an alkali metal salt is preferable.

[Ratio of (A) component and (B) component]
The thickener for cosmetics according to the present embodiment contains 0.1 part by mass or more and less than 25 parts by mass of the component (A) with respect to 100 parts by mass of the total amount of the component (A) and the component (B). By containing the component (A) in an amount of 0.1 part by mass or more and less than 25 parts by mass, as described above, the excellent viscosity and the feeling of use of the component (B) are not impaired, and the viscosity recovery rate is increased. The salt resistance can be significantly improved while suppressing the decrease.

The amount of the component (A) is preferably 0.30 parts by mass or more, more preferably 0.50 parts by mass or more, based on 100 parts by mass of the total amount of the component (A) and the component (B). The amount of the component (A) is preferably 24 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5.0 parts by mass or less, and particularly preferably 2.0 parts by mass. It is less than a part. Viscosity recovery is higher as the amount of component (A) is smaller, while salt resistance is as good as around 10 parts by mass even with a very small amount of component (A) of 2.0 parts by mass or less. can get. Therefore, by setting the amount of the component (A) to, for example, 0.30 to 5.0 parts by mass, more preferably 0.50 to 2.0 parts by mass, the excellent viscosity and usability of the component (B) can be obtained. It is possible to improve salt resistance without impairing the above, and while suppressing a decrease in viscosity recovery rate and an increase in cost due to the addition of component (A).

The thickener for cosmetics according to the present embodiment contains the above-mentioned component (A) and component (B). For example, the component (A) and the component (B) are used as the component (C) in water. The composition may be mixed with the same, or the component (A) and the component (B) may be put in separate containers and combined. The method of mixing the component (A), the component (B), and the component (C) is not particularly limited, and the mixture is prepared by uniformly stirring at an arbitrary temperature using a mixer such as a homomixer according to a conventional method. Can be done.

Further, as the cosmetic containing the thickener for cosmetics, the composition of the thickener for cosmetics in which the component (A) and the component (B) are mixed in advance as described above is used as a cosmetic. It may be prepared by adding and mixing other components such as the active ingredient of. Alternatively, it may be prepared by mixing the active ingredient as a cosmetic with the component (A) and the component (B) when preparing the cosmetic. That is, it suffices that the component (A) and the component (B) are contained in the cosmetic at the stage when the cosmetic is prepared and exerts a thickening effect.

In the cosmetic thickener according to the present embodiment, the contents of the component (A) and the component (B) are not particularly limited. For example, when the thickener for cosmetics contains water as the component (C), the content of the component (A) may be 0.005% by mass or more and less than 25% by mass of the total amount of the thickener for cosmetics. It may be 0.1 to 10% by mass, 0.5 to 5% by mass, and the content of the component (B) may be 0.1% by mass or more and less than 75% by mass of the total amount of the thickener for cosmetics. It may be 1 to 30% by mass, or 5 to 25% by mass. Further, in this case, the content of water as the component (C) is not particularly limited, and may be, for example, 0.01 to 99.9% by mass or 1 to 99% by mass of the total amount of the thickener for cosmetics. It may be 5 to 80% by mass.

In addition to water as the component (C), various components that can be blended in the cosmetics may be blended in the thickener for cosmetics according to the present embodiment. In that case, such other components may be blended in a composition obtained by mixing the component (A), the component (B) and the component (C). Further, when the component (A) and the component (B) are put in separate containers and combined, for example, the above other components are contained in a dispersion solution obtained by mixing the components (A) and the component (C). The above-mentioned other components may be blended in a solution obtained by mixing the component (B) and the component (C).

The cosmetic according to the present embodiment contains a thickener for cosmetics containing the above-mentioned components (A) and (B). In the cosmetic, the contents of the component (A) and the component (B) are not particularly limited, but the content of the component (A) may be 0.005 to 2.0% by mass of the total amount of the cosmetic. It is preferable, more preferably 0.007 to 1.0% by mass, and even more preferably 0.010 to 0.50% by mass. The content of the component (B) is preferably 0.05 to 3.0% by mass, more preferably 0.10 to 2.0% by mass, and 0.20 to 1% of the total amount of the cosmetics. It may be 0.0% by mass.

The cosmetic according to the present embodiment preferably contains water as the component (C). The content of water is not particularly limited, and may be 20.0 to 99.9% by mass, 30.0 to 99.7% by mass, or 40.0 to 99.5% by mass of the total amount of cosmetics. , 90.0 to 99.5% by mass.

In the cosmetics according to the present embodiment, various components generally blended in cosmetics can be arbitrarily blended together with the thickener for cosmetics.

The thickener for cosmetics and the components that can be blended in the cosmetics are not particularly limited, and for example, powder components (inorganic powder, organic powder, inorganic pigment, organic pigment, etc.), surfactants, oils, moisturizers, etc. Metal ion sequestering agents, lower alcohols, polyhydric alcohols, monosaccharides, oligosaccharides, polysaccharides, amino acids, organic amines, pH regulators, vitamins, antioxidants, antioxidant aids, preservatives, deodorants, fragrances, Examples thereof include anti-inflammatory agents, whitening agents, various extracts (plant extracts, etc.), activators, blood circulation promoters, antilipids, anti-inflammatory agents, and the like. These can be used alone or in combination of two or more.

The method for producing the cosmetic is not particularly limited, and each of the above components can be prepared by uniformly stirring at an arbitrary temperature using a mixer such as a homomixer.

The viscosity of the cosmetic according to the present embodiment is not particularly limited because it differs depending on the desired function and the like, but from the viewpoint of usability, thickening, etc., the viscosity at 25 ° C. is preferably 1000 to 300,000 mPa · s. It is preferably 2500 to 250,000 mPa · s. Viscosity is BH type viscometer (less than 80,000 mPa · s: rotor No. 4, rotation speed 2.5 rpm, 3 minutes, 25 ° C, 80,000 mPa · s or more: rotor No. 5, rotation speed 2.5 rpm, 3 minutes, 25 ℃).

The cosmetic according to this embodiment preferably has, for example, a creamy, gelling, milky or liquid dosage form. Specifically, lotion, milky lotion, cold cream, vanishing cream, massage cream, emollient cream, cleansing cream, beauty liquid, pack, foundation, sunscreen cosmetics, suntan cosmetics, moisture cream, hand cream, whitening milky lotion, Skin cosmetics such as various lotions, shampoo, rinse, hair conditioner, rinse-in shampoo, hair styling agent (hair foam, gel hair styling product, etc.), hair treatment agent (hair cream, treatment lotion, etc.), hair dye and lotion It can be used as a type of hair restorer or a hair lotion such as a hair restorer.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The following Example 4 is a reference example.

[Preparation of cellulose fiber a]
To 2 g of coniferous pulp, 150 ml of water, 0.25 g of sodium bromide, and 0.025 g of 2,2,6,6-tetramethylpiperidinooxy radical (TEMPO) were added, and the mixture was thoroughly stirred and dispersed. A 13 mass% sodium hypochlorite aqueous solution (cooxidant) was added to 1.0 g of the pulp so that the amount of sodium hypochlorite was 6.5 mmol / g, and the reaction was started. Since the pH decreases as the reaction progresses, the reaction was carried out while dropping a 0.5 N sodium hydroxide aqueous solution so as to maintain the pH at 10 to 11 until no change in pH was observed (reaction time: 120 seconds). ). After completion of the reaction, 0.1N hydrochloric acid was added to adjust the pH to 7.0, and filtration and washing with water were repeated for purification to obtain cellulose fibers a having an oxidized fiber surface.

Regarding the cellulose fiber a, it was confirmed on the ¹³ C-NMR chart whether or not only the hydroxyl group at the C6 position of the glucose unit on the surface of the cellulose fiber was selectively oxidized to the carboxy group. That is, the peak of 62 ppm corresponding to the C6 position of the primary hydroxyl group of the glucose unit, which can be confirmed on the ¹³ C-NMR chart of cellulose before oxidation, disappears after the oxidation reaction, and instead, a peak derived from the carboxy group is found at 178 ppm. It was appearing. From this, it was confirmed that in the cellulose fiber a, only the C6-position hydroxyl group of the glucose unit was oxidized to the carboxy group.

[Preparation of CNF1]
Cellulose fiber a was diluted with pure water so that the solid content concentration was 2% by mass, and treated once with an ultrahigh pressure homogenizer (manufactured by Sanwa Engineering Co., Ltd., H11) at a pressure of 100 MPa to prepare CNF1. With respect to the obtained CNF1, the carboxy group amount, maximum fiber diameter, number average fiber diameter, and average aspect ratio of the cellulose fibers were measured according to the following criteria. As a result, the amount of carboxy groups was 1.83 mmol / g, the maximum fiber diameter was 10 nm, the number average fiber diameter was 3 nm, and the average aspect ratio was 250.

[Preparation of CNF2]
Cellulose fiber a was diluted with pure water so that the solid content concentration was 2% by mass, and treated with an ultrahigh pressure homogenizer (manufactured by Sanwa Engineering Co., Ltd., H11) 20 times at a pressure of 100 MPa to prepare CNF2. With respect to the obtained CNF2, the maximum fiber diameter, the number average fiber diameter, and the average aspect ratio of the cellulose fibers were measured according to the following criteria. As a result, the maximum fiber diameter was 7 nm, the number average fiber diameter was 3 nm, and the average aspect ratio was 80.

[Measurement of carboxy group amount]
60 ml (cellulose mass: 0.25 g) of an aqueous dispersion of cellulose fibers was prepared, the pH was adjusted to about 2.5 with a 0.1 M hydrochloric acid aqueous solution, and then a 0.05 M sodium hydroxide aqueous solution was added dropwise to generate electricity. Conductivity was measured. The measurement was continued until the pH reached about 11. The amount of carboxy group was determined according to the following formula from the amount of sodium hydroxide (V) consumed in the neutralization step of a weak acid whose electrical conductivity changed slowly.
Carboxylic acid group amount (mmol / g) = V (mL) x [0.05 / cellulose mass (g)]

[Maximum fiber diameter, number average fiber diameter]
The maximum fiber diameter and the number average fiber diameter of the cellulose fibers in the aqueous dispersion of the cellulose fibers were observed using a transmission electron microscope (TEM) (JEM-1400, manufactured by JEOL Ltd.). That is, from a TEM image (magnification: 10000 times) in which each cellulose fiber was cast on a hydrophilized carbon film-coated grid and then negatively stained with 2% uranyl acetate, the maximum fiber diameter and the maximum fiber diameter and The number average fiber diameter was calculated.

[Average aspect ratio]
From the observation image similar to the measurement of the number average fiber diameter, the number average fiber length of the cellulose fiber is calculated according to the method described above, and the average aspect ratio is calculated below using the values of the number average fiber diameter and the number average fiber length. Calculated according to the formula.
Average aspect ratio = number average fiber length (nm) / number average fiber diameter (nm)

[Preparation of thickener composition]
A thickener composition was prepared according to the formulation (parts by mass) shown in Table 1 below. Specifically, a 2% by mass aqueous dispersion of the component (A) and a 2% by mass aqueous solution of the component (B) are mixed so that their solid contents have a blending ratio as shown in Table 1. (That is, the blending amounts of the components (A) and (B) in Table 1 are the amounts as solids), T.I. K. The mixture was stirred with a homomixer at 8000 rpm for 10 minutes. After stirring, the mixture was degassed, transferred to a 100 mL screw tube, and allowed to stand for 24 hours.

As the 2% by mass aqueous dispersion of the component (A), CNF1 and CNF2 prepared above were used. In Comparative Example 1, CMC (carboxymethyl cellulose naritum, cellogen BSH-6 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was used as a comparative component of the cellulose fiber of the component (A).

A 2% by mass aqueous solution of the component (B) was prepared as follows. Regarding the carboxyvinyl polymer in Table 1, Carbopol Ultraz 30 manufactured by Lubrizol was dissolved in pure water, and a 12% sodium hydroxide aqueous solution was added to adjust the pH to 7, and a carboxyvinyl polymer aqueous solution having a solid content concentration of 2% by mass was added. Was prepared.

Regarding the alkyl-modified carboxyvinyl polymer in Table 1, Ultrez 20 manufactured by Lubrizol was dissolved in pure water, and a 12% aqueous sodium hydroxide solution was added to adjust the pH to 7, and the solid content concentration was 2% by mass. A vinyl polymer aqueous solution was prepared.

[Measurement of viscosity X]
The viscosity X of the composition obtained above after standing for 24 hours was measured with a BH type viscometer (less than 80,000 mPa · s: rotor No. 4, rotation speed 2.5 rpm, 3 minutes, 25 ° C., 80,000 mPa · s or more: The measurement was performed using rotor No. 5, rotation speed 2.5 rpm, 3 minutes, 25 ° C.).

[Measurement of viscosity Y]
A 2% by mass aqueous dispersion of the component (A) and a 2% by mass aqueous solution of the component (B) were mixed so that their solid contents had a blending ratio as shown in Table 1, and T.I. K. The mixture was stirred with a homomixer at 8000 rpm for 10 minutes. To 100 parts by mass of the composition after stirring, 0.1 part by mass of sodium chloride was added to T.I. K. The mixture was stirred with a homomixer at 8000 rpm for 5 minutes. After stirring, the mixture was degassed, transferred to a 100 mL screw tube, and allowed to stand for 24 hours. The viscosity Y of the obtained composition was measured with a BH type viscometer (less than 80000 mPa · s: rotor No. 4, rotation speed 2.5 rpm, 3 minutes, 25 ° C., 80000 mPa · s or more: rotor No. 5, rotation speed 2). It was measured using .5 rpm, 3 minutes, 25 ° C.).

[Evaluation of salt tolerance]
The salt tolerance of each composition was calculated according to the following formula.
Salt resistance [%] = 100-{(viscosity X-viscosity Y) / viscosity X} x 100

[Measurement of viscosity recovery rate]
The screw tube containing the above composition whose viscosity X was measured was vigorously shaken by hand to stir the composition, and after allowing this to stand for 1 minute, the viscosity Z was measured with a BH type viscometer (less than 80,000 mPa · s: rotor No.). .4, rotation speed 2.5 rpm, 3 minutes, 25 ° C., 80,000 mPa · s or more: rotor No. 5, rotation speed 2.5 rpm, 3 minutes, 25 ° C.). The viscosity recovery rate of each of the prepared compositions was calculated according to the following formula.
Viscosity recovery rate [%] = (viscosity Z / viscosity X) x 100

The results are shown in Table 1. In Comparative Examples 2 and 3 in which the component (A) was not blended, the viscosity X was high and the viscosity was excellent, but the viscosity Y when salt was added was significantly reduced, and the salt resistance was inferior. Even in Comparative Example 1 in which CMC was used as the comparative component of the component (A), the viscosity Y when salt was added was significantly reduced, and the effect of improving salt resistance was hardly observed.

In Comparative Examples 4 and 5, the salt resistance was greatly improved as compared with Comparative Examples 1 to 3 by adding the cellulose fiber of the component (A). However, the change in viscosity before and after stirring was large, and the viscosity recovery was inferior.

On the other hand, in Examples 1 to 8 in which the components (A) and (B) were combined, the salt resistance was significantly improved as compared with Comparative Examples 1 to 3, and compared with Comparative Examples 4 and 5. The viscosity recovery was improved, and the viscosity recovery rate was about the same as that of Comparative Examples 1 to 3.

Specifically, from the comparison between Example 4 and Comparative Example 4, the amount of the component (A) was 24 parts by mass and 28.8 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). The change in the viscosity recovery rate was large between them, and when it became 25 parts by mass or more, the viscosity recovery rate suddenly decreased in Comparative Example 4.

Moreover, when the comparison was made in Examples 1 to 5 in which only the ratio of the component (A) and the component (B) was changed, the salt resistance was as shown in Examples 3 and 5, and the ratio of the component (A) was extremely small. Even so, the same excellent effect as in Examples 1 and 2 blended in about 10 parts by mass was observed.

As described above, according to the present embodiment, by combining a small amount of the cellulose fiber of the component (A) together with the carboxyvinyl polymer as the component (B), the alkyl-modified carboxyvinyl polymer and the like, the excellent component (B) has. It is possible to significantly improve salt resistance without impairing the viscosity increase and usability, and while suppressing a decrease in the viscosity recovery rate. Therefore, it can be used for various cosmetics having a creamy, gelling, milky or liquid dosage form.

Claims (4)

It contains the following components (A) and (B), and contains 0.3 parts by mass or more and 16 parts by mass or less of the component (A) with respect to 100 parts by mass of the total amount of the components (A) and (B). Thickener for cosmetics (except when it contains amphoteric metals) .
Component (A): Cellulose fiber having a maximum fiber diameter of 1000 nm or less and a number average fiber diameter of 2 to 150 nm, and having a cellulose I-type crystal structure.
(B) Ingredient: At least one selected from the group consisting of carboxyvinyl polymers, alkyl-modified carboxyvinyl polymers and salts thereof. In the cellulose fiber of the component (A), the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule is selectively oxidized and modified to a carboxy group, and the ratio of the carboxy group is 0.6 to 2.3 mmol / g. , The thickener for cosmetics according to claim 1. A cosmetic containing the cosmetic thickener according to claim 1 or 2. The cosmetic according to claim 3, wherein the content of the component (A) is 0.005 to 2.0% by mass, and the content of the component (B) is 0.05 to 3.0% by mass.