Soft-focus agent and stratum corneum softening agent

Abstract

To provide a novel soft-focus agent.SOLUTION: A soft-focus agent for skin includes an ester synthesized from component X, component Y, and component Z as an active component, or the soft-focus agent consists of the ester, wherein the component X is at least one selected from divalent alcohols with 2 to 8 carbon atoms, the component Y is at least one selected from divalent carboxylic acids with 2 to 10 carbon atoms, and the component Z is at least one selected from hydroxycarboxylic acids with 4 to 6 carbon atoms that have two or more carboxyl groups.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] [First technical field of the present invention] The first invention relates to a soft focus agent for skin. [Second technical field of the present invention] The second invention relates to a stratum corneum softening agent for skin. [Background technology]

[0002] [First Background Art of the Invention] As a cosmetic having a soft focus effect, for example, Patent Document 1 reports a cosmetic composition characterized by containing (A) spherical silicone particles having protrusions chemically bonded to the surface, and (B) polyorganosiloxane.

[0003] Furthermore, Patent Document 2 discloses soft focus agents such as polymethyl / methacrylate (PMMA), silica, hybrid pigments, for example, alumina-treated mica, titanium dioxide-treated talc, titanium dioxide-treated mica, vinyl dimethicone / methicone silsesquioxane crosspolymer, alumina, soft focus powders including barium sulfate and synthetic mica, and silicone elastomers (e.g., paragraph 0041).

[0004] [Background Art of the Second Invention] The stratum corneum tends to harden with age. This hardening of the stratum corneum can cause cracks in the skin. It can also cause wrinkles.

[0005] For this reason, it is important to keep the stratum corneum of the skin soft.

[0006] For example, Patent Document 3 has reported a skin softening agent having a skin softening effect and containing a specific low-molecular-weight acetylated hyaluronic acid as a main component. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-137953 [Patent Document 2] Special Publication No. 2008-521882 [Patent Document 3] Japanese Patent Application Publication No. 09-071602 Summary of the Invention [Problem to be solved by the invention]

[0008] [First Object of the Invention] As disclosed in the above-mentioned Patent Documents 1 and 2, conventional soft focus agents mainly use powder, and many of them achieve a soft focus effect by scattering reflected light from the powder in multiple directions.

[0009] A first object of the present invention is to provide a novel soft-focus agent.

[0010] [Second Object of the Invention] There is still a need for development of stratum corneum softeners for the skin.

[0011] A second object of the present invention is to provide a novel stratum corneum softening agent for skin. [Means for solving the problem]

[0012] The present invention that achieves the above object is as follows.

[0013] The first aspect of the present invention that achieves the above object is as follows.

[0014] <Aspect 1-1> A soft focus agent for skin, the soft focus agent contains, as an active ingredient, an ester synthesized from component X, component Y, and component Z, or consists of the ester; The component X is at least one selected from dihydric alcohols having 2 to 8 carbon atoms, The component Y is at least one selected from dicarboxylic acids having 2 to 10 carbon atoms, and The component Z is at least one selected from hydroxycarboxylic acids having 4 to 6 carbon atoms and two or more carboxy groups. Soft focus agent. <Aspect 1-2> The soft focus agent according to Aspect 1-1, wherein Component X is at least one selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, neopentyl glycol, 1,2-octanediol, and 1,6-octanediol. <Aspects 1-3> The soft focus agent according to Aspect 1-1 or 1-2, wherein Component Y is at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, glutaric acid, adipic acid, sebacic acid, and azelaic acid. <Aspect 1-4> The soft focus agent according to any one of Aspects 1-1 to 1-3, wherein Component Z is at least one selected from the group consisting of malic acid, tartaric acid, and citric acid. <Aspects 1-5> A cosmetic composition comprising the soft focus agent according to any one of Aspects 1-1 to 1-4.

[0015] The second aspect of the present invention that achieves the above object is as follows. <Aspect 2-1> A stratum corneum softening agent for skin, the stratum corneum softening agent contains, as an active ingredient, an ester synthesized from component X, component Y, and component Z, or consists of the ester; The component X is at least one selected from dihydric alcohols having 2 to 8 carbon atoms, The component Y is at least one selected from dicarboxylic acids having 2 to 10 carbon atoms, and The component Z is at least one selected from hydroxycarboxylic acids having 4 to 6 carbon atoms and two or more carboxy groups. Stratum corneum softener. <Aspect 2-2> The stratum corneum softening agent according to Aspect 2-1, wherein Component X is at least one selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, neopentyl glycol, 1,2-octanediol, and 1,6-octanediol. <Aspect 2-3> The stratum corneum softening agent according to aspect 2-1 or 2-2, wherein component Y is at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, glutaric acid, adipic acid, sebacic acid, and azelaic acid. <Aspect 2-4> The stratum corneum softening agent according to any one of Aspects 2-1 to 2-3, wherein component Z is at least one selected from the group consisting of malic acid, tartaric acid, and citric acid. <Aspect 2-5> A cosmetic composition comprising the stratum corneum softening agent according to any one of Aspects 2-1 to 2-4. [Effects of the Invention]

[0016] [First Effect of the Present Invention] According to the first aspect of the present invention, a novel soft focus agent can be provided.

[0017] [Second Effect of the Present Invention] According to the second invention, a novel stratum corneum softening agent for skin can be provided. [Brief explanation of the drawings]

[0018] [Figure 1]FIG. 1 is a diagram showing the ratio of storage modulus of Examples 2-1 and 2-2 and Comparative Example 2-1 to that of Comparative Example 2-1. DETAILED DESCRIPTION OF THE INVENTION

[0019] [First Invention] The first embodiment of the present invention will be described in detail below. Note that the first embodiment of the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the present invention.

[0020] <Soft focus agent> The soft focus agent of the first aspect of the present invention is A soft focus agent for skin, the soft focus agent contains, as an active ingredient, an ester synthesized from component X, component Y, and component Z, or consists of the ester; Component X is at least one selected from dihydric alcohols having 2 to 8 carbon atoms, Component Y is at least one selected from dicarboxylic acids having 2 to 10 carbon atoms, and Component Z is at least one selected from hydroxycarboxylic acids having 4 to 6 carbon atoms and two or more carboxy groups. Soft focus agent is.

[0021] The soft-focus agent of the first invention is a novel agent that has never been seen before and can provide a soft-focus effect when applied to the skin. Without being limited by theory, it is presumed that this is because at least a portion of the ester of the first invention can exhibit a scattering effect on the surface layer of the skin due to its unique structure and properties.

[0022] In the first aspect of the present invention, the soft focus agent refers to a cosmetic base having the effect of making uneven skin tone such as blemishes, freckles, and dullness, as well as uneven skin texture such as pores and wrinkles, less visible (soft focus effect).

[0023] In the first aspect of the present invention, the soft focus effect can be evaluated by measuring the haze using a haze meter. The higher the haze value, the higher the soft focus effect. Here, the haze can be calculated using the following formula (a):

number

[0024] The soft focus agent of the first present invention contains, as an active ingredient, an ester synthesized from component X, component Y, and component Z (hereinafter also referred to as "the ester of the present invention"), or consists of the ester of the present invention. The ester of the present invention according to the first present invention will be described in detail below.

[0025] Esters of the Invention The ester of the present invention is synthesized from component X, component Y, and component Z.

[0026] Here, component X is at least one selected from dihydric alcohols having 2 to 8 carbon atoms. Furthermore, from the viewpoint of improving the solubility in water and usability of the ester of the present invention, component X is preferably at least one selected from dihydric alcohols having 2 to 6 carbon atoms, more preferably at least one selected from dihydric alcohols having 2 to 4 carbon atoms, and even more preferably at least one selected from linear dihydric alcohols having 3 to 4 carbon atoms.

[0027] More specifically, component X may be at least one selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, neopentyl glycol, 1,2-octanediol, and 1,6-octanediol.

[0028] According to a first embodiment of the present invention, component X is preferably 1,3-propanediol and / or 1,4-butanediol, more preferably 1,3-propanediol.

[0029] In the first aspect of the present invention, component Y is at least one selected from dicarboxylic acids having 2 to 10 carbon atoms. Furthermore, from the viewpoint of improving the solubility in water and usability of the ester of the present invention, component Y is preferably at least one selected from dicarboxylic acids having 2 to 8 carbon atoms, more preferably at least one selected from dicarboxylic acids having 2 to 6 carbon atoms, and even more preferably at least one selected from saturated dicarboxylic acids having 4 to 6 carbon atoms.

[0030] More specifically, component Y may be at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, glutaric acid, adipic acid, sebacic acid, and azelaic acid.

[0031] According to a first embodiment of the present invention, component Y is preferably succinic acid and / or adipic acid.

[0032] In the first aspect of the present invention, component Z is at least one selected from hydroxycarboxylic acids having 4 to 6 carbon atoms and two or more carboxy groups. Furthermore, from the viewpoint of improving the usability of the ester of the present invention, component Z is preferably at least one selected from hydroxycarboxylic acids having one hydroxy group and two or more carboxy groups and having 4 to 6 carbon atoms.

[0033] More specifically, component Z may be at least one selected from the group consisting of malic acid, tartaric acid, and citric acid.

[0034] According to a first embodiment of the present invention, component Z is preferably malic acid and / or citric acid, more preferably malic acid.

[0035] In the ester of the present invention, the proportion of the constituent component derived from component X (hereinafter referred to as “X mol% ") is not particularly limited and may be, for example, 50 mol% or more, 51 mol% or more, 52 mol% or more, 53 mol% or more, 54 mol% or more, 55 mol% or more, 56 mol% or more, 57 mol% or more, 58 mol% or more, 59 mol% or more, or 60 mol% or more, and may be 65 mol% or less, 64 mol% or less, 63 mol% or less, 62 mol% or less, 61 mol% or less, 60 mol% or less, 59 mol% or less, 58 mol% or less, 57 mol% or less, 56 mol% or less, 55 mol% or less, 54 mol% or less, 53 mol% or less, 52 mol% or less, or 51 mol% or less.

[0036] In the ester of the present invention, the proportion of the constituent component derived from component Y (hereinafter referred to as “Y mol% ") is not particularly limited and may be, for example, 1 mol% or more, 2 mol% or more, 3 mol% or more, 4 mol% or more, 5 mol% or more, 6 mol% or more, 7 mol% or more, 8 mol% or more, 9 mol% or more, 10 mol% or more, 11 mol% or more, 12 mol% or more, 13 mol% or more, 14 mol% or more, 15 mol% or more, 16 mol% or more, 17 mol% or more, 18 mol% or more, 19 mol% or more, 20 mol% or more, 21 mol% or more, or 22 mol% or more, or may be 25 mol% or less, 24 mol% or less, 23 mol% or less, 22 mol% or less, 21 mol% or less, 20 mol% or less, 19 mol% or less, 18 mol% or less, 17 mol% or less, 16 mol% or less, 15 mol% or less, 14 mol% or less, or 13 mol% or less.

[0037] In the ester of the present invention, the proportion of the constituent component derived from component Z (hereinafter referred to as “Z mol% ") is not particularly limited and may be, for example, 25 mol % or more, 26 mol % or more, or 27 mol % or more, and may be 34 mol % or less, 33 mol % or less, 32 mol % or less, 31 mol % or less, 30 mol % or less, 29 mol % or less, 28 mol % or less, or 27 mol % or less.

[0038] In addition, the above-mentioned X mol% , Y mol% , and Z mol%The standard is the sum of the components derived from components X to C. mol% , Y mol% , and Z mol% is the ester of the present invention 1 This value is calculated by analyzing a chart of 1 H NMR (frequency: 400 MHz, solvent: deuterated methanol).

[0039] The hydroxyl value of the ester of the present invention is not particularly limited and may be, for example, 100 to 500 mgKOH / g, preferably 200 to 450 mgKOH / g, and more preferably 300 to 400 mgKOH / g.

[0040] The kinematic viscosity of the ester of the present invention at 40°C is not particularly limited, and may be, for example, 100 to 600 mm 2 / s, 150 to 450 mm 2 / s, and 150 to 300 mm 2 / s is more preferable.

[0041] The ester of the present invention can be produced by an esterification reaction of component X, component Y, and component Z. Esterification reactions are well known to those skilled in the art, and those skilled in the art can produce the ester of the present invention by appropriately setting the conditions for the esterification reaction.

[0042] The esterification reaction is usually carried out while removing water from the system in order to promote the reaction. The esterification reaction may be carried out under normal pressure or under reduced pressure. The temperature of the esterification reaction may be, for example, 100 to 200°C. In order to obtain an ester with excellent color, the temperature of the esterification reaction is preferably 100 to 160°C, more preferably 120 to 150°C.

[0043] The esterification reaction may be carried out in the presence of a catalyst (for example, a Bronsted acid catalyst or a Lewis acid catalyst) or in the absence of a catalyst.

[0044] The progress of the esterification reaction can be monitored by measuring the acid value of the reaction mixture. The resulting ester is preferably purified by a known method. For example, free carboxylic acid remaining in the reaction mixture may be removed using an alkaline aqueous solution, or the reaction mixture may be distilled, deodorized with steam, or treated with activated carbon for the purpose of reducing odor and improving stability.

[0045] The first soft focus agent of the present invention may contain the ester of the present invention as an active ingredient or may consist of the ester of the present invention. Therefore, when the first soft focus agent of the present invention contains the ester of the present invention as an active ingredient, the content of the ester of the present invention is not particularly limited and may be, for example, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or 100% by mass or less, based on the total mass of the soft focus agent.

[0046] <<Cosmetic Composition>> The first present invention also provides a cosmetic composition comprising the soft focus agent of the first present invention.

[0047] The content of the soft focus agent of the first present invention in the cosmetic composition of the first present invention is not particularly limited, and may be, for example, an amount such that the soft focus agent of the first present invention accounts for 0.001 to 90 mass%, 0.1 to 50 mass%, or 0.1 to 20 mass%, or even 0.1 to 10 mass%, of the entire cosmetic composition. More specifically, for example, the content of the first soft focus agent of the present invention may be 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, or 2.0% by mass or more, relative to the total cosmetic composition, and may be 95% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 9.0% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, 2.0% by mass or less, or 1.0% by mass or less.

[0048] The cosmetic composition of the first invention may be used in the form of a liquid, emulsion, cream, powder, foam, solid, etc. Furthermore, the cosmetic composition of the first invention may be, for example, a solution system, a solubilized system, an emulsion system, a powder dispersion system, a water-oil two-layer system, a water-oil-powder three-layer system, a gel, a mist, a spray, a mousse, a roll-on, or a stick, or may be a preparation impregnated into or applied to a sheet such as a nonwoven fabric.

[0049] The cosmetic composition of the first aspect of the present invention is preferably used as a cosmetic composition that is particularly required to have a soft focus effect, and / or as a cosmetic composition that is required to correct skin irregularities such as pores and fine wrinkles and to improve the skin texture after makeup is applied.

[0050] Furthermore, cosmetics that require a soft focus effect and / or cosmetics that require improving the texture of the skin after makeup are not particularly limited, and examples thereof include makeup cosmetics such as foundation, concealer, blush, face powder (face powder, loose powder, pressed powder), control color, primer, BB cream, eye color, and lipstick; and skin care cosmetics such as emulsion, cream, serum, day cream, and sunscreen.

[0051] In addition, these cosmetics may generally contain cosmetic ingredients such as film-forming polymers, surfactants, thickeners, water, moisturizers, fragrances, pigments or dyes, water-repellent oil components such as silicone oil, UV absorbers, astringents, cooling agents, anti-inflammatory agents, whitening agents, various extracts, plant and seaweed extracts, etc. in appropriate amounts depending on the intended use or form of use, but are not limited to these ingredients.

[0052] [Second Invention] The second embodiment of the present invention will be described in detail below. Note that the second embodiment of the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the present invention.

[0053] 《Stratum corneum softener》 The stratum corneum softening agent of the second present invention is A stratum corneum softening agent for skin, The stratum corneum softening agent contains an ester synthesized from component X, component Y, and component Z as an active ingredient, or consists of the ester; Component X is at least one selected from dihydric alcohols having 2 to 8 carbon atoms, Component Y is at least one selected from dicarboxylic acids having 2 to 10 carbon atoms, and Component Z is at least one selected from hydroxycarboxylic acids having 4 to 6 carbon atoms and two or more carboxy groups. stratum corneum softener is.

[0054] The stratum corneum softening agent of the second invention is a novel agent that has never been seen before and can provide a softening effect when applied to the skin. Without being limited by theory, this is thought to be due to the amphiphilic nature of the ester of the present invention used in the second invention. Here, because of this amphiphilic nature of the ester of the present invention, it is thought that it can easily penetrate the stratum corneum of the skin, thereby interacting with keratin in the stratum corneum (for example, by interrupting the hydrogen bonds between keratin molecules), thereby increasing the softness of the stratum corneum.

[0055] Furthermore, the stratum corneum softening agent of the second present invention is also expected to have the effect of improving skin wrinkles by softening the stratum corneum.

[0056] Furthermore, according to the above-mentioned speculated mechanism, it can be said that the skin softening effect of the stratum corneum softening agent of the second present invention is different from the skin softening effect of some specific moisturizing agents.

[0057] For example, the above-mentioned Patent Document 1 discloses the skin softening effect of a specific low-molecular-weight acetylated hyaluronic acid.The mechanism of the skin softening effect in this case is thought to be as follows: That is, the specific low-molecular-weight acetylated hyaluronic acid has excellent affinity with the skin and can be retained on the skin surface.It is therefore presumed that the moisture evaporating from the inside of the stratum corneum is captured on the skin surface, thereby maintaining the softening effect of the stratum corneum.However, not all moisturizing agents with moisturizing effect can necessarily exhibit the stratum corneum softening effect as in the above-mentioned Patent Document 1.

[0058] Esters of the Invention The stratum corneum softener of the second invention contains the ester of the present invention as an active ingredient or consists of the ester of the present invention. Note that the ester of the present invention of the second invention is the same as the "ester of the present invention" of the "first invention" described above, and therefore a detailed description thereof will be omitted here. Note that in the description of the ester of the present invention of the first invention described above, the part relating to the "first invention" should be read as the "second invention" as appropriate.

[0059] In the second invention, the stratum corneum softener of the second invention may contain the ester of the present invention as an active ingredient, or may consist of the ester of the present invention. Therefore, when the stratum corneum softener of the second invention contains the ester of the present invention as an active ingredient, the content of the ester of the present invention is not particularly limited, and may be, for example, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or 100% by mass or less, based on the total mass of the stratum corneum softener.

[0060] <<Cosmetic Composition>> The second invention also provides a cosmetic composition comprising the stratum corneum softening agent of the second invention.

[0061] The content of the stratum corneum softener of the second present invention in the cosmetic composition of the second present invention is not particularly limited, and may be, for example, an amount such that the content of the stratum corneum softener of the second present invention is 0.001 to 90 mass%, 0.1 to 50 mass%, or 0.1 to 20 mass%, or even 0.1 to 10 mass%, relative to the total mass of the cosmetic composition. More specifically, for example, the stratum corneum softener of the second present invention may be present in an amount of 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, or 2.0% by mass or more, relative to the total cosmetic composition, and may be present in an amount of 95% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 9.0% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, 2.0% by mass or less, or 1.0% by mass or less.

[0062] Furthermore, the cosmetic composition of the second present invention may optionally further contain various ingredients in addition to the stratum corneum softening agent of the second present invention.

[0063] Examples of such components include oils such as liquid paraffin, squalane, lanolin derivatives, higher alcohols, various ester oils, silicone oils, polyalkylene glycol polyethers and other carboxylic acids, oligoester compounds, and terpene hydrocarbon oils; surfactants, ultraviolet absorbers, ultraviolet scattering agents, acrylic resins, silicone resins, and resins such as polyvinylpyrrolidone; proteins or protein hydrolysates such as soy protein, gelatin, collagen, silk fibroin, and elastin; preservatives such as ethylparaben and butylparaben; activators such as biotin and pantothenic acid derivatives; diluents such as ethanol, isopropanol, and tetrachlorodifluoroethane toluene; thickeners such as carboxyvinyl polymers; chelating agents, antioxidants, moisturizers; drugs such as tranexamic acid, nicotinamide, potassium 4-methoxysalicylate, retinol, and retinol acetate; fragrances; and colorants, but are not limited to these.

[0064] The cosmetic composition of the second present invention may be used in the form of a liquid, emulsion, cream, powder, foam, solid, etc. Furthermore, the cosmetic composition of the second present invention may be, for example, a solution system, a solubilized system, an emulsion system, a powder dispersion system, a water-oil two-layer system, a water-oil-powder three-layer system, a gel, a mist, a spray, a mousse, a roll-on, or a stick, or may be a preparation impregnated into or applied to a sheet such as a nonwoven fabric. [Example]

[0065] The first and second aspects of the present invention will be described in more detail below with reference to examples, but the first and second aspects of the present invention are not limited to these examples.

[0066] [First Invention] Synthesis Example 1 200 g (2.63 mol) of 1,3-propanediol, 34.9 g (0.24 mol) of adipic acid, and 134.1 g (0.56 mol) of malic acid were charged into a four-neck flask. Under a nitrogen atmosphere, the reaction water was distilled off at 130°C under normal pressure. The acid value was measured every hour, and the reaction was continued until the rate of decrease in the acid value per hour reached 0.5 or less. Next, the acid value was measured every hour at the same temperature and under a reduced pressure of 1 to 5 kPa. The reaction was continued until the rate of decrease in the acid value per hour reached 0.5 or less, yielding a crude ester. Subsequently, 350 g of ethyl acetate was charged, and the mixture was washed with water to remove excess 1,3-propanediol. The ethyl acetate was then removed by distillation under reduced pressure. Next, acid clay and a silica-alumina-based adsorbent were added in amounts of 1.0 mass% of the ester amount, respectively, and an adsorption treatment was carried out. The temperature, pressure, and time of the adsorption treatment were 100°C, 1 to 5 kPa, and 2 hours. Finally, filtration was carried out using a 1 micron filter to obtain ester 1.

[0067] Synthesis Example 2 1,3-propanediol 230g (3.02mol), succinic acid 59.5g (0.5 64.5g (0.34mol) of citric acid was placed in a four-neck flask. The subsequent steps were carried out in the same manner as in Synthesis Example 3 above, to obtain ester 2.

[0068] <Physical properties of esters 1 and 2> The resulting esters 1 and 2 were analyzed for various physical properties according to the following methods. The analytical results are shown in Table 1-1.

[0069] (composition) The resulting esters 1 and 2 were each 1 Perform H NMR measurement and X mol% , Y mol% , and Z mol% was calculated.

[0070] (Hydroxyl value) The hydroxyl values of the resulting esters 1 and 2 were measured in accordance with JIS K0070.

[0071] (Kinematic viscosity) The kinematic viscosities of the resulting esters 1 and 2 were measured in accordance with JIS K2283.

[0072] (Solubility in water) A 50% by mass aqueous solution of the resulting esters 1 and 2 was prepared, and the appearance was visually confirmed. If the appearance was uniform, it was evaluated as "Good", and if it was not uniform, it was evaluated as "Poor".

[0073] (Solubility in olive oil) A 1% by mass olive oil solution of the obtained ester was prepared, and its appearance was visually confirmed. If the appearance was uniform, it was rated as "Good", and if it was not uniform, it was rated as "Poor".

[0074] [Table 1-1]

[0075] Examples 1-1 and 1-2, and Comparative Example 1-1 In Examples 1-1 and 1-2, 5% by mass aqueous solutions of the above-obtained esters 1 and 2 were prepared, respectively, and the soft focus effect was evaluated. In Comparative Example 1-1, 100% water was used.

[0076] (Evaluation of soft focus effect) The haze value (cloudiness value) was measured using a haze meter manufactured by Murakami Color Research Institute.

[0077] More specifically, the haze of the human stratum corneum was measured before application of each sample, and then a 5% by mass aqueous solution of each sample was applied. 24 hours later, the haze was measured again, and the haze before and after application was compared. The results are shown in Table 1-2.

[0078] [Table 1-2]

[0079] As is clear from the results in Table 1-2, the difference in haze obtained by subtracting the haze value before application from the haze value 24 hours after application was larger for the aqueous solutions of Examples 1-1 and 1-2 than for Comparative Example 1-1.

[0080] That is, it was found that the aqueous solutions of Examples 1-1 and 1-2 containing Esters 1 and 2, respectively, had a soft focus effect. In other words, it was suggested that Esters 1 and 2 could each be used as a soft focus agent.

[0081] [Second Invention] Synthesis Examples 1 and 2 described below were synthesized in the same manner as in "Synthesis Examples 1 and 2" in the experimental section of the above-mentioned "First Invention." Various physical property values of the obtained Ester 1 and Ester 2 were as shown in the above-mentioned Table 1-1.

[0082] Examples 2-1 and 2-2, and Comparative Example 2-1 In Examples 2-1 and 2-2, 5% by mass aqueous solutions of the above-obtained esters 1 and 2 were prepared, respectively, and the stratum corneum softening effect was evaluated. In Comparative Example 2-1, 100% water was used.

[0083] The stratum corneum softening effect was evaluated as follows.

[0084] <Evaluation of stratum corneum softening effect> The softening effect on the stratum corneum was evaluated based on the storage modulus (E') of the stratum corneum. The lower the storage modulus, the softer the stratum corneum, suggesting a higher softening effect on the stratum corneum.

[0085] Specifically, we used a horizontal-drive dynamic viscoelasticity analyzer, the DVA-220 (IT Measurement and Control Co., Ltd.). Both ends of a human stratum corneum strip prepared by trypsin treatment were held horizontally by two clamps attached to the measurement section of the device. The measurement section was configured as a variable temperature and humidity chamber, and was set to a skin surface temperature of 32°C and a relative humidity of 50% (dry season). One clamp applied a fixed-amplitude sinusoidal stress (0.2% strain, 1 Hz) to one end of the stratum corneum. The other clamp was equipped with a highly sensitive sensor that detected weak stress transmitted through the stratum corneum. The detected stress signal was converted into the dynamic storage modulus (E') and dynamic loss modulus (E''). Of these, E' was used as an index of stratum corneum flexibility. A smaller E' value indicates a softer stratum corneum. The effect of each sample on E' was evaluated by measuring E' of the stratum corneum treated with each sample.

[0086] For ease of comparison, the storage modulus ratio of each example and comparative example to that of Comparative Example 2-1 was calculated using the storage modulus value of Comparative Example 2-1 as the standard. The results are shown in Figure 1.

[0087] As is clear from the results in FIG. 1, it was found that the storage modulus values of Examples 2-1 and 2-2, which used Esters 1 and 2, respectively, were significantly lower than those of Comparative Example 2-1.

[0088] In other words, these results suggest that both Ester 1 and Ester 2 have a significantly high effect of softening the stratum corneum.

Claims

1. A soft focus agent for skin, the soft focus agent contains, as an active ingredient, an ester synthesized from component X, component Y, and component Z, or consists of the ester; The component X is at least one selected from dihydric alcohols having 2 to 8 carbon atoms, The component Y is at least one selected from dicarboxylic acids having 2 to 10 carbon atoms, and The component Z is at least one selected from hydroxycarboxylic acids having 4 to 6 carbon atoms and two or more carboxy groups. Soft focus agent.

2. 2. The soft focus agent according to claim 1, wherein component X is at least one selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, neopentyl glycol, 1,2-octanediol, and 1,6-octanediol.

3. 2. The soft focus agent according to claim 1, wherein the component Y is at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, glutaric acid, adipic acid, sebacic acid, and azelaic acid.

4. 2. The soft focus agent according to claim 1, wherein the component Z is at least one selected from the group consisting of malic acid, tartaric acid, and citric acid.

5. A cosmetic composition comprising the soft focus agent according to any one of claims 1 to 4.

6. A stratum corneum softening agent for skin, the stratum corneum softening agent contains, as an active ingredient, an ester synthesized from component X, component Y, and component Z, or consists of the ester; The component X is at least one selected from dihydric alcohols having 2 to 8 carbon atoms, The component Y is at least one selected from dicarboxylic acids having 2 to 10 carbon atoms, and The component Z is at least one selected from hydroxycarboxylic acids having 4 to 6 carbon atoms and two or more carboxy groups. Stratum corneum softener.

7. 7. The stratum corneum softening agent according to claim 6, wherein component X is at least one selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, neopentyl glycol, 1,2-octanediol, and 1,6-octanediol.

8. The stratum corneum softening agent according to claim 6, wherein the component Y is at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, glutaric acid, adipic acid, sebacic acid, and azelaic acid.

9. The stratum corneum softening agent according to claim 6, wherein the component Z is at least one selected from the group consisting of malic acid, tartaric acid, and citric acid.

10. A cosmetic composition comprising the stratum corneum softening agent according to any one of claims 6 to 9.

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