Cosmetics

Abstract

To provide cosmetics that achieve both moisturization and skin firmness.SOLUTION: Cosmetics contain (A), (B) and (D). The combined total content of (B), and an optional component, (C), is 4-20 mass% relative to the total amount of the cosmetics. The mass ratio of component (B) to the total amount of components (B) and (C), [(B) / [(B)+(C)]], is 0.4-1. (A) One or more selected from polyvinyl alcohol, pullulan, modified starch and dextran. (B) Tripropyleneglycol. (C) Any polyhydric alcohol, excluding tripropylene glycol. (D) Water.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to cosmetics.

Background Art

[0002] As methods for enhancing the firmness and elasticity of the skin, methods of blending active ingredients such as plant extracts and vitamin A derivatives are known. However, these methods take time for the active ingredients to exhibit their pharmacological effects and lack an immediate sense of effect, making it difficult to encourage long-term continuous use until the pharmacological effects are manifested. Therefore, in order to enhance the perceived effect of skincare cosmetics and encourage continuous use, efforts have been made to physically give firmness to the skin after applying the cosmetics to provide an immediate sense of effect. As a means of physically giving firmness to the skin by applying cosmetics and immediately enhancing the firmness of the skin, a method using a film-forming agent is known (Patent Documents 1 to 3). This is understood to be an effect in which the entire face feels tightened due to the shrinkage of the film-forming agent when a cosmetic containing the film-forming agent is applied to the skin. Several techniques for enhancing the shrinkability of film-forming agents in cosmetics have been proposed. For example, a liquid cosmetic composition for wrinkle relaxation characterized by containing silica for increasing the film-forming shrinkage force in a film-forming substance has been proposed (Patent Document 4). A skin cosmetic excellent in the feeling of tightening and firmness of the skin has been proposed by containing a lower alcohol, spherical powder, film-forming agent, and cooling agent (Patent Document 5). However, these techniques have a problem in that the use of powder or highly volatile lower alcohol tends to cause a feeling of dryness and roughness on the skin.

[0003] Generally, polyhydric alcohols such as glycerin and propylene glycol are used as humectants in skincare cosmetics and are added in a certain amount or more to impart a moisturizing feeling. However, these polyhydric alcohols act as plasticizers in cosmetics using a film-forming agent and make the film soft (Patent Documents 6 and 7). Therefore, when using film-forming agents to give the skin a firming effect, the polyhydric alcohols added as moisturizers also act as plasticizers, causing the film-forming agents to soften and lose their elasticity, resulting in a problem where sufficient firmness cannot be achieved. In other words, it was difficult to achieve both the moisturizing effect that is inherently expected from skincare cosmetics and the effect of giving the skin a firming sensation. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2021 / 172430 [Patent Document 2] Japanese Patent Publication No. 2021-181502 [Patent Document 3] International Publication No. 2021 / 193918 [Patent Document 4] Japanese Patent Application Publication No. 05-000933 [Patent Document 5] Japanese Patent Publication No. 2000-239139 [Patent Document 6] Special Publication No. 2019-504058 [Patent Document 7] Special Publication No. 2008-533202 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The objective of this invention is to provide a cosmetic product that can achieve both moisturizing and firming effects on the skin. [Means for solving the problem]

[0006] The means for solving the problems of the present invention are as follows. 1. Contains (A), (B), and (D), The total amount of (B) and the optional (C) is 4 to 20% by mass of the total amount of cosmetic product. A cosmetic product in which the mass ratio of (B) to the sum of (B) and (C) [(B) / [(B)+(C)]] is between 0.4 and 1. (A) From polyvinyl alcohol, pullulan, modified starch and dextran One or more will be selected. (B) Tripropylene glycol (C) Polyhydric alcohols other than tripropylene glycol (D)Water 2. The cosmetic composition according to 1, wherein (C) the polyhydric alcohol other than tripropylene glycol is one or more selected from glycerin, diglycerin, propylene glycol, dipropylene glycol, butylene glycol, pentylene glycol, and hexanediol. 3. The cosmetic composition according to 1. or 2., wherein (A) the modified starch contains one or more selected from hydroxypropyl starch and hydrolyzed hydrogenated starch. [Effects of the Invention]

[0007] The cosmetic composition of the present invention can provide both a moisturizing sensation and a firming sensation to the skin. [Brief explanation of the drawing]

[0008] [Figure 1] Images taken 24 hours after application, used to calculate the area ratio of the cosmetic obtained in Example 1, Comparative Examples 6, 8, and 10. [Modes for carrying out the invention]

[0009] The cosmetic composition of the present invention contains (A), (B), and (D), The total amount of (B) and the optional (C) is 4 to 20% by mass of the total amount of cosmetic product. The mass ratio of (B) to the sum of (C) [(B) / [(B)+(C)]] is between 0.4 and 1. (A) From polyvinyl alcohol, pullulan, modified starch and dextran One or more will be selected. (B) Tripropylene glycol (C) Polyhydric alcohol other than tripropylene glycol (D) Water In the present specification, the notation "X to Y" (X and Y are numerical values) means a numerical range including both ends thereof.

[0010] (A) (A) is one or more selected from polyvinyl alcohol, pullulan, modified starch, and dextran, and two or more thereof can be mixed and used. (A) is a water-soluble polymer and acts as a film-forming agent in the cosmetic of the present invention. As the modified starch, hydroxypropyl starch, hydrolyzed hydrogenated starch, hydrolyzed starch, etc. can be used. Among these, hydroxypropyl starch or hydrolyzed hydrogenated starch is preferable. In the cosmetic of the present invention, the blending amount of (A) is preferably 0.01 to 10% by mass, more preferably 0.05 to 10% by mass, and even more preferably 0.1 to 5% by mass based on the total amount of the cosmetic.

[0011] The polyvinyl alcohol is not particularly limited, and either a partially saponified type with a saponification degree of about 70 to 90% or a completely saponified type with a saponification degree of 90% or more can be used. From the viewpoint of film-forming properties, polyvinyl alcohol having a viscosity of about 10 to 60 mPas in a 4% aqueous solution (20 °C) is preferable. As dextran, any of dextran 40, dextran 70, and high molecular weight dextran can be used. The modified starch is not particularly limited, but those containing an amylopectin (having an α-1,6 bond) structure with excellent film-forming ability are preferable. The starch used for producing the modified starch may be any starch derived from plants, for example, starch derived from corn, rice, beans, potatoes, sweet potatoes, tapioca, bracken, and kudzu can be used.

[0012] (B) (B) Tripropylene glycol (sometimes abbreviated as TPG) is a dihydric alcohol with the molecular formula HO(C3H6O)3H and acts as a humectant. Furthermore, (B) tripropylene glycol has a weak plasticizing effect on the film formed by (A) and enhances the shrinkability of the film, thereby improving the firmness of the skin caused by the film formed by (A).

[0013] (C) The cosmetic composition of the present invention may contain polyhydric alcohols other than (C) tripropylene glycol. (C) can be any polyhydric alcohol used in cosmetic compositions without particular limitations. From the viewpoint of usability, such as stickiness, one or more selected from glycerin, diglycerin, propylene glycol (PG), dipropylene glycol, butylene glycol (1,3-butylene glycol), pentylene glycol (1,2-pentanediol), and hexanediol are preferred. (C) acts as a humectant, just like (B), but unlike (B), it acts strongly as a plasticizer on the film formed by (A).

[0014] In the present invention, the total amount of (B) and the optional component (C) is 4 to 20% by mass of the total amount of the cosmetic composition. If this total amount is less than 4% by mass, the moisturizing effect decreases, and if it exceeds 20% by mass, the film formed by (A) softens, resulting in a decrease in firmness. In the cosmetic composition of the present invention, the mass ratio of (B) to the sum of (B) and (C) [(B) / [(B)+(C)]] is 0.4 to 1. If this mass ratio is less than 0.4, the proportion of (C), which acts as a plasticizer, becomes higher, resulting in a decrease in firmness. If a formulation with a more pronounced firmness is desired, it is even more preferable that the mass ratio of (B) to the sum of (B) and (C) [(B) / [(B)+(C)]] is 0.7 to 1.

[0015] (D) The cosmetic composition of the present invention contains (D) water as an essential component. (D) Water may be added in an amount of 50% by mass or more relative to the total amount of the cosmetic. (D) Water is preferably contained in an amount of 50-96% by mass, and more preferably in an amount of 70-96% by mass.

[0016] In addition to components (A) to (D), the cosmetic composition of the present invention may contain various raw materials commonly used in cosmetics, such as ethanol, moisturizing ingredients other than (B) and (C), thickeners, chelating agents, pH adjusters, neutralizing agents, preservatives, antioxidants, fragrances, colorants (e.g., cyanocobalamin), beauty ingredients (e.g., rosemary extract), vitamins, and other functional ingredients, to the extent that they do not impair the effects of the present invention. Oils may be added to the extent that they do not impair the effects of the present invention. The cosmetic composition of the present invention is preferably in the form of a serum or gel. Because it provides a strong feeling of firmness, it is suitable as a cosmetic for wrinkle improvement and for use around the eyes. [Examples]

[0017] <Preparation of cosmetics> Cosmetics for Examples 1-33 and Comparative Examples 1-45 were prepared by stirring and mixing each component according to the compositions shown in Tables 1-3.

[0018] [Table 1]

[0019] [Table 2]

[0020] [Table 3]

[0021] <Evaluation of cosmetics> 1. Sensory evaluation 0.2 mL of the obtained cosmetic was applied to the cheek. Three minutes after application, one expert sensory evaluator assessed the firmness and moisturizing effect of the cheek based on the feel when touched with a finger. Firmness was defined as "a firm, taut feeling," and moisturizing effect was defined as "a smooth, moist feeling." The results are shown in Tables 1-3. • Criteria for evaluating firmness ◎: Feels very firm ○: Feels firm △: Slightly firm ×: Does not feel firm In this invention, the evaluation result "△: Slightly firm" was determined to indicate that the objective of the present invention has not been achieved. • Criteria for evaluating moisturizing effect ○: Moisturizing ×: Does not provide moisturizing effect

[0022] 2. Evaluation of shrinkage properties of cosmetic coating films The shrinkage properties of the cosmetic coating films were evaluated using the cosmetic compositions obtained in Example 1 and Comparative Examples 6, 8, and 10 according to the following procedure. The cosmetic product was colored by adding Red pigment No. 106 to a concentration of 0.02%. A circle with a diameter of 1.5 cm was drawn on a zinc phosphate-treated steel sheet, and 50 μL of colored cosmetic was applied within this circle. After leaving it at room temperature for 24 hours, the appearance of the coated film was photographed with a digital camera. The obtained images were separated into RGB and then binarized using image analysis software to determine the area of ​​the red-colored portion. As shown in the formula below, the obtained area was divided by the total area of ​​the initial coated area to obtain the area ratio of the cosmetic coating film after 24 hours. Area percentage (%) = ((Area of ​​colored area after 24 hours) / (Area of ​​initial applied area)) × 100

[0023] "result" 1. Results of sensory evaluation Examples 1 to 8 show that (A), the film-forming agent of the present invention, was combined with (B) tripropylene glycol in amounts commonly used in cosmetics. The resulting cosmetics maintained excellent firmness and also provided moisturizing properties. Comparative Examples 1-5 involved combining other film-forming agents with tripropylene glycol in amounts commonly used in cosmetics, but the resulting cosmetics lacked firmness. Comparative Examples 6 and 7 confirmed the user experience when (B) tripropylene glycol was not used. Comparative Example 6, which used only (A) polyvinyl alcohol and (D) water, did not provide a feeling of firmness. Comparative Example 7, which contained a large amount of ethanol to increase the evaporation rate, showed a slight improvement in firmness, but it was not sufficient, and a problem of dryness occurred. Comparative Examples 8-21 combine (A) polyvinyl alcohol, pullulan, hydroxypropyl-modified starch, hydrolyzed hydrogenated starch, and dextran of the present invention with (C) polyhydric alcohols other than tripropylene glycol. As a result, while the polyhydric alcohols other than (C) tripropylene glycol provided a moisturizing effect, they did not provide a firming effect. This is thought to be because the polyhydric alcohols other than (C) tripropylene glycol acted excessively as plasticizers in relation to the film-forming agent.

[0024] Examples 9-21 and Comparative Examples 22-37 examine the total amount of polyhydric alcohols other than tripropylene glycol, using polyvinyl alcohol and pullulan as examples of (A), (B) tripropylene glycol, and (C) other polyhydric alcohols. As a result, in all cases, when the total amount of polyhydric alcohols containing tripropylene glycol ((B) + (C)) was between 4% and 20%, excellent firmness could be achieved, and no firmness was obtained outside this range. Comparative Examples 38-41 examine the ratio and total amount of (B) tripropylene glycol and (C) polyhydric alcohols other than tripropylene glycol. As a result, it was confirmed that the firmness (rated ○ or higher) intended by the present invention cannot be imparted unless the total amount of polyhydric alcohols containing tripropylene glycol [(B) + (C)] is between 4 and 20%, and the mass ratio of (B) to the sum of (B) and (C) [(B) / [(B) + (C)]] is above a certain level.

[0025] Examples 22-33 and Comparative Examples 42-45 examine the blending ratio of polyhydric alcohols, using (B) tripropylene glycol and (C) glycerin or 1,3-butylene glycol as examples. The results confirmed that a superior firming sensation is obtained when the mass ratio of (B) to the sum of (C) [(B) / [(B)+(C)]] is 0.4 or higher. Furthermore, it was found that an even stronger firming sensation is obtained when the mass ratio [(B) / [(B)+(C)]] is 0.7 or higher.

[0026] 2. Results of evaluation of shrinkage of cosmetic coating film Figure 1 shows the image taken 24 hours later, which was used to calculate the area ratio. Table 4 shows the calculated area ratio. [Table 4]

[0027] The cosmetic composition obtained in Example 1, which contains the specific film-forming agent (A) and (B) tripropylene glycol of the present invention, underwent a significant shrinkage of approximately 20% in area ratio. (B) The cosmetic composition obtained in Comparative Example 6, which did not contain tripropylene glycol, had an area ratio of approximately 60%. In Comparative Examples 8 and 10, where (C) other polyhydric alcohols, namely glycerin and propylene glycol, were used instead of (B) tripropylene glycol, the cosmetic compositions obtained had area ratios of approximately 90% and 70%, respectively, and did not shrink much. This is presumed to be because (C) the other polyhydric alcohols acted as plasticizers, inhibiting the shrinkage of the film. Furthermore, the area ratio (%) results were consistent with the evaluation results for "firmness" in the sensory evaluation. Specifically, firmness was observed only in Example 1, where the area ratio was 50% or less.

Claims

1. (A), (B), and (D) are included. The total amount of (B) and the optional (C) is 4 to 20% by mass of the total amount of cosmetic product. A cosmetic product in which the mass ratio of (B) to the sum of (B) and (C) [(B) / [(B) + (C)]] is between 0.4 and 1. (A) One or more selected from polyvinyl alcohol, pullulan, modified starch, and dextran (B) Tripropylene glycol (C) One or more selected from glycerin, diglycerin, propylene glycol, dipropylene glycol, butylene glycol, pentylene glycol, and hexanediol. (D) Water

2. (A) The cosmetic composition according to claim 1, wherein the modified starch comprises one or more selected from hydroxypropyl starch and hydrolyzed hydrogenated starch.

Images