JP2024044253A - Wipe-off cosmetics - Google Patents

Abstract

[Problem] The objective of the present invention is to provide a wipe-off cosmetic that can be wiped off without putting a strain on the skin when wiped off and can remove aged keratin without causing skin irritation. [Solution] A wipe-off cosmetic that contains (A) a monoester of phosphoric acid and a higher alcohol having a straight-chain structure, or a salt thereof, (B) a basic compound, and (C) a monohydric higher alcohol having a straight-chain structure, and is characterized in that the degree of neutralization of (B) with respect to the acid value of (A) is 0.1 or more and 1.0 or less. [Effect] This is expected to restore the original moisture and smoothness of the skin and improve dullness. [Selected Figure] Figure 1

Description

The present invention relates to a wipe-off cosmetic that can be wiped off without putting a burden on the skin when wiped off, and that can remove aged keratin without causing skin irritation.

In skin aging, the stratum corneum (hereafter referred to as aged keratin) which would normally turn into dirt and be shed under normal metabolic conditions, often remains instead of being shed. This aged keratin is hard and dry, and its moisturizing ability is significantly reduced. The aged keratin also contains melanin pigment which should be excreted. Therefore, when the aged keratin remains instead of being shed, the stratum corneum as a whole becomes hard and thickened, the skin loses moisture and smoothness, and its appearance changes to a dull one with a reduced sense of transparency.

In light of the above, it is thought that by removing aged keratin, the skin's original moisture and smoothness can be restored and dullness can be improved. Cosmetics that achieve this effect are called wipe-off cosmetics. There are no restrictions on how wipe-off cosmetics can be used, but they are generally used by soaking a cosmetic tool such as cotton with the cosmetic and wiping it off the skin.

The purpose of washing the face with a typical face wash is to remove various types of dirt, mainly oil-soluble dirt such as sebum and makeup, that have accumulated on the skin, through the action of the cleansing ingredients. It is known that various components in the skin, such as cholesterol and sebum, are removed when washing the face with these cleansing ingredients (Non-Patent Document 1). It is also known that cosmetics generally referred to as cleansing or makeup removers are made for the purpose of removing makeup cosmetics, which are oily components, from the skin. On the other hand, wipe-off cosmetics differ from typical cleansing agents and cleansing agents in that they are not intended to remove oily dirt such as cholesterol and sebum, but rather have the effect of removing water-soluble dirt, especially aging keratin (Non-Patent Document 2).

Alkaline cosmetics (Patent Document 1) have been known as cosmetics with an exfoliating effect. By incorporating basic substances such as potassium hydroxide and potassium carbonate, alkaline cosmetics have the effect of increasing the permeability of water and water-soluble components into aged keratin, making it easier to remove. However, alkaline cosmetics can cause skin irritation, raising safety concerns.

Another issue is that skin irritation can occur due to friction caused by the skin during the wiping action. Conventionally, skin irritation caused by friction has been suppressed by blending natural polysaccharides such as xanthan gum and synthetic anionic compounds such as (acrylates/alkyl acrylate (C10-30)) crosspolymers as polymeric ingredients used in cosmetics to impart viscosity to the formulation. However, while blending polymeric ingredients basically improves the slipperiness of cotton soaked in the cosmetic wipe, it also reduces the amount of keratin that can be collected by physical contact with the cotton. In other words, there is a trade-off between the blending of polymeric ingredients and the effect of removing keratin, so there was a need for a technology that would make it easier to remove keratin while reducing friction during the wiping action.

Fumito Hashimoto, Michiko Haruyama, Tokio Yamashita, Toshiaki Iso, Adsorption of surfactants to skin and selective cleansing ability by facial cleansers, J.Soc. Cosmet. Chem. Japan. Vol. 23, No. 2 1989 Mai Horitsuji, Miho Morita, Akinori Inoue, Noritake Kitatani, Evaluation of the usefulness of wipe care, J.Soc.Cosmet.Chem.Japan.Vol.53, No. 3 2019

Japanese Patent Application Publication No. 11-322570

The objective of the present invention is to provide a wipe-off cosmetic product that can be wiped off without placing a burden on the skin and can remove aged keratin without causing skin irritation.

As a result of intensive research into the problem, the inventors have been able to obtain a wipe-off cosmetic product that can remove aged keratin without putting a strain on the skin when wiping off by combining (A) a monoester of phosphoric acid and a higher alcohol having a linear structure, or a salt thereof, (B) a basic compound, and (C) a monohydric higher alcohol having a linear structure, and by setting the degree of neutralization of (B) relative to the acid value of (A) to 0.1 to 1.0.

According to the present invention, aged keratin can be removed without putting a burden on the skin during wiping. This can be expected to restore the skin's original moisture and smoothness and improve dullness.

Schematic diagram of artificial skin (left: part of plan view, right: part of side view)

According to the present invention, (B) a basic compound is used for (A) a monoester of phosphoric acid and a higher alcohol having a linear structure, or a salt thereof, and (B) is used for the acid value of (A). ) By forming a surfactant that undergoes a neutralization reaction with a degree of neutralization in the range of 0.1 or more and 1.0 or less, it prevents basic components from infiltrating into the skin, suppressing skin irritation and providing excellent results. It has an exfoliating effect. Furthermore, in addition to this surfactant, (C) oil-in-water emulsified particles prepared with a monohydric higher alcohol having a linear structure exhibits the effect of reducing physical friction during wiping.

(A) used in the present invention is a monoester of phosphoric acid and a higher alcohol having a linear structure, or a salt thereof. (A) is not limited as long as it is used in ordinary cosmetics. (A) may be a monoester or a salt partially neutralized with a basic compound in advance. Specific examples of monoesters include lauryl phosphate and cetyl phosphate. Specific examples of salts partially neutralized in advance with a basic compound include sodium lauryl phosphate, disodium lauryl phosphate, potassium lauryl phosphate, potassium cetyl phosphate, diethanolamine cetyl phosphate, and the like. The higher alcohol in (A) preferably has a linear structure from the viewpoint of low friction during wiping and exfoliating effect. The number of carbon atoms in the higher alcohol is not particularly limited, but preferably 12 or more carbon atoms. Commercially available products include cetyl phosphate under the trade name "Hostaphat CC100 (acid value: 250-400)" (manufactured by Clariant) and potassium cetyl phosphate under the trade name "Hostaphat CK100 (acid value: 130-155)" (manufactured by Clariant). Examples include "AMPHISOL K (acid value: 130-155)" (manufactured by DSM Nutrition).

The acid value of (A) used in the present invention can be measured in advance by an acid value measurement method in order to confirm the degree of neutralization. Alternatively, when using a commercially available product, the acid value listed in the test report may be used. The acid value measurement method is not particularly limited, but for example, the potassium hydroxide (KOH :56.11) can be used to measure the number of mg, and can be calculated from Equation 1. The first method of this operation is defined as follows.
In addition to what is specified in Act 1, accurately measure the amount of the sample specified in the monograph, place it in a 250 mL flask, and add ethanol (95) or a mixture of ethanol (95)/diethyl ether (1:1) or ethanol (95 )/diethyl ether mixture (2:1), heat to dissolve, and titrate with 0.1 mol/L potassium hydroxide solution while shaking occasionally. (Indicator: 1 mL of phenolphthalein test solution) However, the end point of the titration is the point at which the liquid remains pale pink for 30 seconds. Correct by conducting a blank test in the same manner.

In the present invention, the degree of neutralization calculated by using 1 g equivalent of (B) and the acid value of (A) previously measured by an acid value measurement method is defined as Equation 2. In Equation 2, 1 g equivalent of (B) is the mass per mole of base divided by the valence of the base. For example, in the case of sodium hydroxide (NaOH: 40.00), the valence as a base is 1, so 1 g equivalent of sodium hydroxide is 40.00.

The (A) used in the present invention can be used alone or in combination of two or more kinds. The amount of (A) used in the present invention is not particularly limited, but from the viewpoint of reducing friction during wiping and the effect of removing keratin, the content is preferably 0.1 to 3 mass % of the total amount of the composition, and more preferably 0.3 to 2 mass %.

The basic compound (B) used in the present invention is not particularly limited and can be appropriately selected depending on the purpose. Examples include alkali metal hydroxides, basic amino acids, and organic bases. Examples of the alkali metal hydroxides include sodium hydroxide and potassium hydroxide. Examples of the basic amino acids include lysine and arginine. Examples of the organic bases include ammonium monoethanolamine, diethanolamine, triethanolamine, 2-amino-2-methyl-1-propanol, and 2-amino-2-hydroxymethyl-1,3-propanediol. In particular, from the viewpoint of safety, basic amino acids and/or organic bases are preferable, and more specifically, arginine and 2-amino-2-methyl-1-propanol are preferable.

The amount of (B) used in the present invention can be determined in advance using Equation 3, which is a modification of Equation 2 based on the degree of neutralization. The degree of neutralization is preferably 0.1 or more and 1.0 or less, particularly 0.1 or more and 1.0 or less, from the viewpoint of preventing basic components from infiltrating into the skin and exhibiting an excellent exfoliating effect while suppressing skin irritation. More preferably, it is .3 or more and 0.8 or less. Regarding this range of neutralization degree, the blending amount of (B) calculated from Equation 3 is desirable.

(B) used in the present invention can be used alone or in combination of two or more. When two or more types of (A) and (B) are combined, the degree of neutralization can be calculated from the information of a plurality of (A) and (B) using Equation 4, which is an extension of Equation 2.

A specific example of number 4 will be given. The acid value of potassium cetyl phosphate in (A ₁ ) is 143 and the mass % is 0.8%, the acid value of potassium lauryl phosphate in (A _{2 ) is 125 and the mass % is 0.2%, and the acid value of potassium cetyl phosphate in (A 2 )} is 125 and the mass % is 0.2%. 1 g equivalent of arginine was 174.2, mass % was 0.22%, and 1 g equivalent of 2-amino-2-methyl-1-propanol (B ₂ ) was 89.14, mass % was 0.1%. The degree of neutralization in this case could be calculated from equation 4 as 0.960.

Example of substitution to <Number 4>

The number of carbon atoms in the monovalent higher alcohol having a linear structure (C) used in the present invention is not particularly limited, but a monovalent linear saturated alcohol having 16 to 22 carbon atoms is preferred. Examples include cetyl alcohol, stearyl alcohol, and behenyl alcohol.

The (C) used in the present invention can be used alone or in combination of two or more kinds. The blending amount of the (C) used in the present invention is not particularly limited, but from the viewpoint of forming oil-in-water emulsion particles and exerting the effect of reducing physical friction during wiping, the content is preferably 0.1 to 6 mass % relative to the total amount of the composition, and more preferably 0.5 to 4 mass %.

In addition to the above-mentioned essential ingredients, the wiping cosmetic of the present invention may contain water, surfactants, polyhydric alcohols, lower alcohols, and alcohols, if necessary, within a qualitative and quantitative range that does not impede the effects of the present invention. Contain ingredients other than the essential ingredients normally used in cosmetics, such as sticky agents, water-soluble polymers, preservatives, chelating agents, medicinal ingredients, oils, silicones, antioxidants, ultraviolet absorbers, fragrances, and pigments. Can be done.

The method of using the wipe-off cosmetic composition of the present invention is not particularly limited, but an example of its use is to apply it to a cosmetic tool such as cosmetic cotton and wipe the skin. Therefore, it is preferable that the wipe-off cosmetic composition of the present invention is in a liquid form that can be applied to a cosmetic tool.

The present invention will be further explained with reference to Examples below. Note that these do not limit the present invention in any way. The blending amount is mass % based on the total amount of the composition.

For the Examples and Comparative Examples, effectiveness tests were carried out using wipe-off cosmetics having the formulations shown in Table 1 below.
[Manufacturing method for wipe-off cosmetics]
Components A, C and other oil components in the table were dissolved by heating at 80°C, mixed with component B and other aqueous components similarly dissolved by heating at 80°C, treated with HomoMoxer, and cooled to room temperature to prepare samples. Note that components A' and C'1 in the table were added according to components A and C, respectively. Component C'2 was mixed with the aqueous component and then added.

(Less friction when wiping)
[Evaluation method]
The static friction coefficient (μS) was measured using a surface property measuring device (TYPE-14 manufactured by Shinto Scientific Co., Ltd.) for the cosmetics prepared in the examples and comparative examples. A cotton wipe (Pure Touch Cotton: manufactured by Naris Cosmetics Co., Ltd.: 310 g/ ^m2 ) cut into a circle with a diameter of 30 mm was sandwiched between an artificial skin holder with a radius of 50 mm, which imitates the curvature of a finger, and 1.5 ml of the cosmetic was dropped onto the cotton. This holder was set on the arm of the measuring device, and a weight of 50 g was placed as a horizontal load. The artificial skin described below was set on the moving stage of the measuring device. The static friction coefficient was measured at a moving speed of 3,000 mm/min.
[Evaluation criteria]
The coefficient of static friction was divided into four levels and used as the evaluation value. These four levels are the evaluation ranges in which the difference can be clearly recognized in the sensory evaluation by expert panelists.
◎: Less than 1.3 (very good, with very little friction against the skin)
Good: 1.3 or more and less than 1.4 (low friction against the skin, excellent)
△: 1.4 or more but less than 1.5 (friction against the skin is felt)
×: 1.5 or more (a lot of friction against the skin)

Figure 1 is a schematic diagram of the artificial skin used in the measurements. Artificial skin with a pattern of skin grooves and skin ridges was modeled on a 50 mm x 90 mm x 10 mm flat plate using a 3D printer with UV-curable acrylic resin. The artificial skin had the pattern shown on the left side of the figure, and each pattern was modeled to be a square with sides of 0.6 mm, with skin grooves 0.15 mm wide (the cross section is almost rectangular with a slightly narrowed base) and skin grooves 0.025 mm deep.

(Exfoliating effect)
[Evaluation method]
The amount of aged keratin removed by wiping was confirmed by protein quantification using the cosmetics prepared in the examples and comparative examples. 1 mL of lotion was soaked in cotton, and the cotton was wiped 20 times in a constant direction over an area of 5 cm x 14 cm on the back of a person washed with warm water. At this time, the wipe was performed with a constant force. The wiped cotton was placed in a tube, 1.5 mL of 8M urea was added thereto, and incubated overnight at 37°C to extract protein. The extract was squeezed out with a syringe, the sample liquid was collected, and protein quantification was performed using the BCA method to measure the amount of wiped protein. 40 μL of the collected sample solution was added to the 96 Cell Culture Cluster, and Reagent A (1% bicinchoninic acid, 2 _{% Na2CO3 ,} 0.16% tartaric acid, 0.4% NaOH, 0.95% _NaHCO3 aqueous solution) and Reagent B (4% _{CuSO4.5H2O aqueous} solution) were mixed in a ratio of 50:1 and added in 200 μL each. After incubation at 37°C for 30 minutes, the absorbance at 540 nm was measured. At the same time, bovine blood albumin (BSA) was diluted in three stages, starting from a concentration of 0.4 mg/mL, in two-fold increments, to create a calibration curve. The amount of dissolved protein was calculated from this calibration curve. Using this method, the higher the value, the more protein was wiped off, and it can be determined that the effect of removing aged keratin is high.
[Evaluation criteria]
The protein quantification results were divided into four levels and used as evaluation values.
◎: 0.28 mg or more (extremely effective in removing aging keratin)
〇: 0.24 mg or more to less than 0.28 mg (highly effective in removing aging keratin)
△: 0.20 mg or more to less than 0.24 mg (almost no effect on removing aging keratin)
×: Less than 0.20 mg (no effect on removing aging keratin)

(Skin irritation)
[Evaluation method]
Ten monitors who had previously experienced skin troubles from wipe-off cosmetics were asked to use the lotions prepared according to the example formulation and the comparative example formulation for one week, and a questionnaire was filled out regarding the presence or absence of skin troubles such as itching or redness, to evaluate safety.
[Safety evaluation criteria]
○: 0 out of 10 monitors reported having skin problems.
△: One or two out of ten monitors reported having skin problems.
×: Three or more out of ten monitors reported having skin problems.

According to Table 1, in Examples 1 to 5, the oil-in-water emulsion particles formed by neutralizing the acid value of (A) with the degree of neutralization of (B) in the range of 0.1 to 1.0 and (C) with the surfactant prevented the basic component from infiltrating into the skin, suppressed skin irritation, and exhibited an excellent exfoliating effect and reduced physical friction during wiping. In Examples 6 and 7, it was confirmed that the same effect could be obtained even when the types of (A), (B), and (C) were changed. In Example 8, it was confirmed that the same effect could be obtained when two types of (B) were used, and in Example 9, it was confirmed that the same effect could be obtained when two types of (A) and two types of (B) were used.
On the other hand, in Comparative Example 1, the neutralization degree of (B) with respect to the acid value of (A) is 0.1 or less, and the keratin removal effect is not sufficient. In Comparative Example 2, the neutralization degree of (B) with respect to the acid value of (A) is 1.0 or more, so it is considered that the basic component infiltrates into the skin and induces skin irritation. In Comparative Example 3, an anionic surfactant having a structure similar to that of the component (A) consisting of a fatty acid having an alkyl group and glutamic acid is used instead of the component (A). However, the prepared oil-in-water emulsion particles are unstable, and the oil-water is separated after 24 hours of preparation, so that the effect of reducing physical friction during wiping is not shown. In Comparative Example 4, a nonionic surfactant with an acid value of 1 or less is used. The state of the prepared oil-in-water emulsion particles is good, but the effect of reducing physical friction during wiping is not shown. In addition, since this nonionic surfactant does not have a functional group that neutralizes basic compounds, the basic component induces skin irritation. In Comparative Example 5, a monohydric higher alcohol having a branched structure was used instead of the component (C), and the oil-in-water emulsion particles prepared in the same manner as in Comparative Example 3 were unstable and did not exhibit the effect of reducing physical friction during wiping. Comparative Example 6 is a case in which a polymer component was blended instead of the component (C). It was confirmed that the effect of reducing physical friction during wiping was exhibited, but the exfoliating effect was inhibited.

From the results in Table 1, it can be seen that the wipe-off cosmetic of the example was a composition that reduced friction on the skin and removed aged keratin without causing skin irritation. By using the present invention, it is possible to provide a wipe-off cosmetic that can be wiped off without putting a strain on the skin and can remove aged keratin without causing skin irritation.

Compositions of each formulation were prepared in a conventional manner. It was confirmed that the effects of the present invention can be achieved in any formulation.

(1) Wiping gel: Prescription example 1
Ingredient name Amount (%)
Cetyl phosphate 3
2-amino-2-hydroxymethyl-1,3-propanediol 0.7
Behenyl alcohol 6
Hydroxypropyl methylcellulose 0.05
Polyethylene glycol (average molecular weight: 1540) 1
Methylphenylpolysiloxane 2
1,3-butylene glycol 8
Preservative Appropriate amount of purified water Total remaining amount 100
Neutralization degree 0.997

(2) Wipe lotion: Prescription example 2
Ingredient name Amount (%) Potassium cetyl phosphate 1
Sodium hydroxide 0.05
Setanol 0.5
1,3-butylene glycol 8
glycerin 4
Glyceryl tri-2-ethylhexanoate 0.2
PEG-50 hydrogenated castor oil 0.5
PPG-6 decyltetradeceth-30 0.5
Sodium carbonate 0.025
Sodium hydrogen carbonate 0.05
Preservative Appropriate amount of purified water Total remaining amount 100
Neutralization degree 0.490

(3) Wipe-off serum: Formulation example 3
Ingredient name Amount (%)
Lauryl phosphate (acid value: 400) 0.1
Arginine 0.05
Potassium hydroxide 0.02
Stearyl alcohol 1
1,3-butylene glycol 5
Polysorbate 20 1
Sodium hyaluronate 0.05
Carboxyvinyl polymer 0.01
Ethanol 5
Disodium edetate (as needed) Preservative (as needed) Purified water (as needed) Total balance 100
Neutralization degree: 0.903

By using the present invention, it is possible to provide a cosmetic for wiping that removes aged keratin without placing a burden on the skin when wiping off and without causing skin irritation.

Claims (2)

(A) A monoester of phosphoric acid and a higher alcohol having a linear structure, or a salt thereof (B) A basic compound (C) A monoester containing a monovalent higher alcohol having a linear structure; A wipe-off cosmetic, characterized in that the degree of neutralization of (B) relative to the value is 0.1 or more and 1.0 or less. The wipe-off cosmetic according to claim 1, wherein the basic compound (B) is a basic amino acid and/or an organic base.