Soft focus agent and stratum corneum softening agent

Abstract

Provided is a novel soft focus agent and a stratum corneum softening agent.　Provided are a soft focus agent for the skin and a stratum corneum softening agent. The soft focus agent and the stratum corneum softening agent each contain a polymer (I) having a structure represented by formula (1) as an active ingredient, or each are formed from polymer (I) and polymer (I) has a structure represented by formula (1).

Description

Soft focus agent and stratum corneum softener

[0001] [Technical Field of the First Invention] The first invention relates to a soft focus agent for skin.

[0002] [Technical Field of the Second Invention] The second invention relates to a stratum corneum softening agent for skin.

[0003] [Background Art of the First 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.

[0004] 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).

[0005] [Background Art of the Second Invention] The stratum corneum tends to harden with age. Hardening of the stratum corneum can cause cracks in the skin. Hardening of the stratum corneum can also cause wrinkles on the skin.

[0006] For this reason, it is important to keep the stratum corneum of the skin soft.

[0007] 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.

[0008] JP 2008-137953 Publication Special Table 2008-521882 JP 09-071602

[0009] [First Problem of the Present 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.

[0010] A first object of the present invention is to provide a novel soft-focus agent.

[0011] [Second Object of the Invention] There is still a need for development of stratum corneum softening agents for the skin.

[0012] A second object of the present invention is to provide a novel stratum corneum softening agent for skin.

[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, comprising, as an active ingredient, a polymer (I) having a structure represented by the following formula (1), or consisting essentially of the polymer (I): In the formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50, the number average molecular weight of the polymer (I) is 10,000 or less, and the IOB value of the polymer (I) is 0.4 to 1.8. <Aspect 1-2> A soft focus agent in which A in the formula (1) is represented by the following formula (2): In the formula (2), R ４ A soft focus agent according to Aspect 1-1, wherein R is an alkyl group having 1 or 2 carbon atoms. Aspect 1-3: The soft focus agent according to Aspect 1-1 or 1-2, wherein the polymer (I) is a random copolymer or a block copolymer. Aspect 1-4: In the formula (1), m is 2 or more and R １Aspect 1-5: In the formula (1), at least a part of R is a methyl group. ２ and R ３ A soft focus agent according to any one of Aspects 1-1 to 1-4, wherein at least one of the following is a methyl group. Aspect 1-6: A cosmetic composition comprising the soft focus agent according to any one of Aspects 1-1 to 1-5.

[0015] The second aspect of the present invention that achieves the above object is as follows.

[0016] <Aspect 2-1> A stratum corneum softening agent for skin, comprising, as an active ingredient, a polymer (I) having a structure represented by the following formula (1), or consisting essentially of the polymer (I): In the formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50, the number average molecular weight of the polymer (I) is 10,000 or less, and the IOB value of the polymer (I) is 0.4 to 1.8. <Aspect 2-2> A stratum corneum softener, wherein A in the formula (1) is represented by the following formula (2): In the formula (2), R ４ The stratum corneum softener according to Aspect 2-1, wherein R is an alkyl group having 1 or 2 carbon atoms. Aspect 2-3: The stratum corneum softener according to Aspect 2-1 or 2-2, wherein the polymer (I) is a random copolymer or a block copolymer. Aspect 2-4: In the formula (1), m is 2 or more, and R １ The stratum corneum softening agent according to any one of Aspects 2-1 to 2-3, wherein at least a portion of R ２ and R ３ A stratum corneum softening agent according to any one of Aspects 2-1 to 2-4, wherein at least one of the following is a methyl group. Aspect 2-6: A cosmetic composition comprising the stratum corneum softening agent according to any one of Aspects 2-1 to 2-5.

[0017] [Effects of the First Invention] According to the first invention, a novel soft focus agent can be provided.

[0018] [Effects of the Second Invention] According to the second invention, a novel stratum corneum softening agent for skin can be provided.

[0019] Figure 1 is a graph showing the haze results for the compositions of Examples 1-3 and 1-4 and Comparative Example 1-2. Figure 2 is a graph showing the soft focus effect of the compositions of Examples 1-3 and 1-4 and Comparative Example 1-2 using a Beaulax pore model. Figure 3 is a graph 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.

[0020] [First Invention] Hereinafter, an embodiment of the first invention will be described in detail. Note that the first invention is not limited to the following embodiment, and various modifications can be made within the scope of the present invention.

[0021] <<Soft-focus Agent>> The soft-focus agent of the first aspect of the present invention is a soft-focus agent for skin, which contains, as an active ingredient, a polymer (I) having a structure represented by the following formula (1), or consists of the polymer (I): In formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50, the number average molecular weight of polymer (I) is 10,000 or less, and the IOB value of polymer (I) is 0.4 to 1.8.

[0022] The soft-focus agent of the first invention is a novel agent that has never been seen before and can impart 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 polymer (I) of the first invention can exhibit a scattering effect in the surface layer of the skin due to its unique structure and properties.

[0023] 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).

[0024] In the first aspect of the present invention, the soft focus effect can be evaluated by measuring the haze value using a haze meter. The higher the haze value, the higher the soft focus effect. Here, the haze value can be calculated using the following formula (a): In the formula: Td: diffuse light transmittance (%), Tt: total light transmittance (%).

[0025] The soft focus agent of the first invention contains polymer (I) as an active ingredient or consists of polymer (I). Polymer (I) of the first invention will be described in detail below.

[0026] <Polymer (I) of the First Invention> The polymer (I) of the first invention has a structure represented by the following formula (1):

[0027] In formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In the first invention, examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. These alkyl groups may further have a substituent, as long as the effects of the first invention are not impaired. The substituent is not particularly limited, and examples thereof include a halogeno group.

[0028] According to a first embodiment of the present invention, in formula (1), R １ , R ２ and R ３ may each independently be a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group.

[0029] According to a first embodiment of the present invention, in formula (1), R １ is preferably a hydrogen atom, a methyl group, or an ethyl group. １ If present, each R １ may be the same or different, and in particular, R １ At least a part of R is preferably a methyl group. １ It is particularly preferable for at least a part of the groups to be methyl groups in order to improve the feeling when used.

[0030] According to a first embodiment of the present invention, in formula (1), R １ may be in a state where hydrogen atoms and alkyl groups having 1 to 4 carbon atoms are mixed. １ A part of R may be a hydrogen atom, and another part may be an alkyl group having 1 to 4 carbon atoms. １ Some of these are hydrogen atoms and some are methyl groups.

[0031] According to a first embodiment of the present invention, in formula (1), R ２ is preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably a methyl group.

[0032] According to a first embodiment of the present invention, in formula (1), R ２ may be in a state where hydrogen atoms and alkyl groups having 1 to 4 carbon atoms are mixed. ２ A part of R may be a hydrogen atom, and another part may be an alkyl group having 1 to 4 carbon atoms. ２ Some of the R are hydrogen atoms and some are methyl groups. １ and R ２ is present and at least a portion of which is a methyl group, R １ and R ２ The ratio of methyl groups to hydrogen (CH ３ / H) is not particularly limited and may be, for example, 0.05 or more, 0.10 or more, 0.15 or more, 0.20 or more, 0.25 or more, 0.30 or more, or 0.35 or more, and may be 0.99 or less, 0.90 or less, 0.80 or less, 0.70 or less, or 0.60 or less.

[0033] According to a first embodiment of the present invention, in formula (1), R ３ is preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably a methyl group. ３ is present and at least a part of it is a methyl group, １ and R ２ In line with １ , R ２ and R ３ The ratio of methyl groups to hydrogen (CH ３ / H) is not particularly limited and may be, for example, 0.05 or more, 0.10 or more, 0.15 or more, 0.20 or more, 0.25 or more, 0.30 or more, or 0.35 or more, and may be 0.99 or less, 0.90 or less, 0.80 or less, 0.70 or less, or 0.60 or less.

[0034] According to a first embodiment of the present invention, in formula (1), R ２ and R ３ At least one of these is preferably a methyl group.

[0035] In formula (1), A is an alkylene group having 2 to 4 carbon atoms. More specifically, A may be, for example, an ethylene group, a propylene group, a butylene group, an isobutylene group, etc., but is not limited to these. In particular, A is preferably represented by the following formula (2):

[0036] In formula (2), R ４ is an alkyl group having 1 or 2 carbon atoms. More specifically, R ４ may be a methyl group or an ethyl group.

[0037] In formula (1), m and n represent the average number of moles of each structural unit added. m and n each independently represent 1.0 to 50, and more specifically, may be 1.0 or more, 1.5 or more, 2.0 or more, 3.0 or more, 4.0 or more, 5.0 or more, 6.0 or more, 7.0 or more, 8.0 or more, 9.0 or more, 10 or more, 15 or more, or 20 or more, or may be 50 or less, 45 or less, 40 or less, 35 or less, 34 or less, 32 or less, 30 or less, 28 or less, 26 or less, 25 or less, 24 or less, 22 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or less, 12 or less, 10 or less, or 5.0 or less.

[0038] In formula (1), m is preferably 1.0 or more and 25 or less, 1.0 or more and 20 or less, or 1.0 or more and 14 or less, and more preferably 2.0 or more and 20 or less, 2.0 or more and 15 or less, or 2.0 or more and 5.0 or less. In formula (1), n ​​is preferably 2.0 or more and 40 or less, 2.0 or more and 35 or less, or 2.0 or more and 34 or less, and more preferably 6.0 or more and 35 or less, or 6.0 or more and 12 or less.

[0039] According to a first embodiment of the present invention, in formula (1), m+n may be 4.0 or more, 4.5 or more, 5.0 or more, 6.0 or more, 7.0 or more, 8.0 or more, 9.0 or more, 10 or more, 11 or more, 12 or more, 13 or more, 14 or more, 15 or more, or 17 or more; and may be 55 or less, 53 or less, 50 or less, 45 or less, 42 or less, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, or 12 or less.

[0040] According to a first embodiment of the present invention, in formula (1), m:n may be 1:10 to 10:1, 1:6 to 6:1, or 1:5 to 5:1.

[0041] The number average molecular weight of the polymer (I) of the first invention is 10,000 or less. More specifically, the number average molecular weight of the polymer (I) of the first invention may be, for example, 10,000 or less, 5,000 or less, 3,500 or less, 3,000 or less, 2,800 or less, 2,600 or less, 2,500 or less, 2,000 or less, 1,500 or less, 1,400 or less, 1,300 or less, 1,200 or less, 1,100 or less, 1,000 or less, 900 or less, 800 or less, 700 or less, or 600 or less, or may be 130 or more, 150 or more, 200 or more, 250 or more, 300 or more, 350 or more, 400 or more, 450 or more, or 500 or more. The number average molecular weight of the polymer (I) of the first invention is preferably 300 or more and 3,500 or less, more preferably 500 or more and 3,500 or less, or more preferably 500 or more and 1,200 or less.

[0042] The IOB value of the polymer (I) of the first present invention is 0.4 to 1.8. More specifically, the IOB value of the polymer (I) of the first present invention may be, for example, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more, and may be 1.8 or less, 1.6 or less, 1.4 or less, 1.2 or less, or 1.0 or less. The IOB value of the polymer (I) of the first present invention is preferably 0.7 or more and 1.2 or less.

[0043] Here, the IOB value is an abbreviation for Inorganic / Organic Balance (inorganic / organic ratio), and is a value that represents the ratio of the inorganic value to the organic value, and serves as an index of the degree of polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. For each of the "inorganic value" and "organic value," "inorganic value" and "organic value" are set according to various atoms or functional groups, such as, for example, an "organic value" of 20 for one carbon atom in a molecule and an "inorganic value" of 100 for one hydroxyl group. The IOB value of an organic compound can be calculated by integrating the "inorganic value" and "organic value" of all atoms and functional groups in the organic compound (see, for example, Yoshio Koda, "Organic Conceptual Diagram - Fundamentals and Applications," pp. 11-17, Sankyo Publishing, 1984). For a method for determining the IOB value, please refer to the method described in the Examples.

[0044] The polymer (I) of the first aspect of the present invention may be a block copolymer or a random copolymer.

[0045] The method for producing the polymer (I) of the first invention is not particularly limited, and may be, for example, by addition polymerization of epoxides corresponding to each structural unit. The addition polymerization may be block polymerization or random polymerization.

[0046] Furthermore, the first method for producing polymer (I) of the present invention may further include reacting the polymer obtained by the above-mentioned addition polymerization with an alkyl halide. Through the reaction with the alkyl halide, the hydroxyl groups in the obtained polymer molecule are blocked with alkyl groups, thereby allowing the hydrophobicity of the entire polymer to be adjusted as desired. In the present invention, the blocking rate of hydroxyl groups with alkyl groups in the polymer molecule may be, for example, 20% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, or 55% or more, and may be 60% or less, 59% or less, 58% or less, 57% or less, 56% or less, or 55% or less. The blocking rate of hydroxyl groups with alkyl groups can be determined by the method described in the Examples.

[0047] One of the features of the polymer (I) of the first invention is that it has both high water solubility and high fat solubility.

[0048] The solubility of the polymer (I) of the first present invention in water can be, for example, 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more.

[0049] In addition, the solubility in olive oil can be used as an index of the fat-solubility of the polymer (I) of the first invention. The solubility in olive oil of the polymer (I) of the first invention can be, for example, 0.01% by mass or more, 0.05% by mass or more, 0.10% by mass or more, 0.50% by mass or more, or 1.00% by mass or more. The upper limit of the solubility in olive oil of the polymer (I) of the first invention is not particularly limited, and may be, for example, 10% by mass or less.

[0050] The soft focus agent of the first invention may contain the polymer (I) of the first invention as an active ingredient, or may consist entirely of the polymer (I) of the first invention. Therefore, when the soft focus agent of the first invention contains the polymer (I) of the first invention as an active ingredient, the content of the polymer (I) of the first 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 amount of the soft focus agent.

[0051] Cosmetic Composition The first present invention also provides a cosmetic composition comprising the soft focus agent of the first present invention.

[0052] 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% by mass, 0.1 to 50% by mass, 0.1 to 20% by mass, or even 0.1 to 10% by mass in 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.

[0053] 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.

[0054] 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.

[0055] 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, base, BB cream, eye color, and lipstick; and skin care cosmetics such as emulsion, cream, serum, day cream, and sunscreen.

[0056] Furthermore, 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.

[0057] [Second Invention] Hereinafter, an embodiment of the second invention will be described in detail. Note that the second invention is not limited to the following embodiment, and various modifications can be made within the scope of the present invention.

[0058] <<Stratum corneum softener>> A stratum corneum softener according to the second aspect of the present invention is a stratum corneum softener for skin, comprising, as an active ingredient, a polymer (I) having a structure represented by the following formula (1), or consisting essentially of the polymer (I): In the formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50, the number average molecular weight of the polymer (I) is 10,000 or less, and the IOB value of the polymer (I) is 0.4 to 1.8.

[0059] The stratum corneum softening agent of the second invention is a novel one that has never been seen before, and can provide a softening effect when applied to the skin. Without being limited by theory, it is thought that this is because the polymer (I) of the second invention is amphiphilic due to its unique structure. Here, because of this amphiphilicity, the polymer (I) is thought to 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), and as a result, it is presumed that the softness of the stratum corneum is increased.

[0060] Furthermore, the stratum corneum softening agent of the second invention is also expected to have the effect of improving skin wrinkles by softening the stratum corneum.

[0061] 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 invention is different from the skin softening effect of some specific moisturizing agents.

[0062] 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, and as a result, the softening effect of the stratum corneum can be maintained.However, not all moisturizing agents with moisturizing effect can necessarily exhibit the stratum corneum softening effect as described in the above-mentioned Patent Document 1.

[0063] <Polymer (1) of the Second Invention> The stratum corneum softener of the second invention contains polymer (I) as an active ingredient or consists of polymer (I). Note that polymer (I) of the second invention is the same as the above-mentioned "polymer (I) of the first invention," so a detailed description thereof will be omitted here. Note that in the above description of "polymer (I) of the first invention," the part relating to "the first invention" should be read as "the second invention" as appropriate.

[0064] In the second invention, the stratum corneum softener of the second invention may contain the polymer (I) of the second invention as an active ingredient, or may consist of the polymer (I) of the second invention. Therefore, when the stratum corneum softener of the second invention contains the polymer (I) of the second invention as an active ingredient, the content of the polymer (I) of the second 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 amount of the stratum corneum softener.

[0065] Cosmetic Composition The second invention also provides a cosmetic composition comprising the stratum corneum softening agent of the second invention.

[0066] 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% by mass, 0.1 to 50% by mass, or 0.1 to 20% by mass, or even 0.1 to 10% by mass, relative to the entire 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] [First Invention] <<Synthesis Examples 1 and 2>> In the following Synthesis Examples 1 and 2, polymers having structures represented by the following formula (3) were synthesized: In the formula (3), the brackets [ ] represent a random copolymer.

[0072] <Synthesis example 1> Synthesis example 1: R １ = H, R ２ = H, R ３ =CH ３ , R ４ =CH ３Polymer 1 having m=2.0 and n=6.0 Polymer 1 was obtained by the following synthesis method.

[0073] 128 g of methanol and 6.4 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen. The catalyst was then completely dissolved at 80°C with stirring. Next, a mixture of 592 g of glycidol and 1,392 g of propylene oxide was added dropwise using a dropping device at 95°C over 20 hours, followed by stirring for 5 hours. The reaction composition was removed from the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at 100°C under a reduced pressure of -0.095 MPa (50 mmHg) for 1 hour to remove contained water. After further treatment, filtration was carried out to remove the salt produced, yielding 2,000 g of Polymer 1 of Synthesis Example 1.

[0074] Various physical property values ​​of the obtained polymer 1 were determined below.

[0075] (Number Average Molecular Weight) The number average molecular weight of the obtained polymer 1 was calculated by gel permeation chromatography (GPC). A SHODEX (registered trademark) GPC101 GPC dedicated system was used as the system, a SHODEX RI-71s differential refractometer, a SHODEX KF-G guard column, and three HODEX KF804L columns were installed in series. The column temperature was 40°C, and tetrahydrofuran was used as the developing solvent at a flow rate of 1 ml / min. 0.1 ml of a 0.1 wt % tetrahydrofuran solution of the obtained reaction product was injected, and a chromatogram expressed as refractive index intensity and elution time was obtained using a BORWIN GPC calculation program. The number average molecular weight was calculated from this chromatogram using polyethylene glycol as the standard, and was found to be approximately 530.

[0076] (Weight Average Molecular Weight) The weight average molecular weight of the obtained polymer 1 was determined by GPC calculation in the same manner as above, and was found to be about 859.

[0077] (Polydispersity) From the results of the number average molecular weight and weight average molecular weight obtained above, the polydispersity Mw / Mn of Polymer 1 was 1.62.

[0078] (IOB Value) The IOB value of the obtained polymer 1 was determined as follows and was found to be 1.1.

[0079] More specifically, in polymer 1, the organic value was calculated using 20 carbon atoms and -10 iso-branching. The inorganic value was calculated using 100 hydroxyl groups and 20 ether bonds. Methanol moiety: (1 carbon atom, 1 hydroxyl group) x 1 Organic value: 20 Inorganic value: 100 Glycidol moiety: (3 carbon atoms, 1 iso-branching, 1 hydroxyl group, 1 ether bond) x 2 Organic value: (60-10) x 2 = 100 Inorganic value: (100 + 20) x 2 = 240 Propylene oxide moiety: (3 carbon atoms, 1 iso-branching, 1 ether bond) x 6 Organic value: (60-10) x 6 = 300 Inorganic value: 20 x 6 = 120 The total organic value is 420, and the total inorganic value is 460, so the IOB value is 1.09.

[0080] (Cloud Point) A 5 wt % aqueous solution of the obtained polymer 1 was prepared, heated to 85° C., and then cooled. The temperature at which the solution became transparent was 74° C. Therefore, the cloud point of polymer 1 was found to be 74° C.

[0081] (Hydroxyl Value) The hydroxyl value of the obtained polymer 1 was 294 when measured according to the measurement method of JIS K-1557-1.

[0082] (Solubility in Water) The solubility of the obtained polymer 1 in water was determined in the same manner as in the "compatibility evaluation" method described below, and was found to be 50% by mass or more.

[0083] (Solubility in Olive Oil) The solubility of the obtained polymer 1 in olive oil was determined as follows. That is, polymer 1 was mixed with olive oil to a concentration of 1.0 wt %, and the appearance was checked. If it was homogeneous, it was rated as "Good." In this case, the solubility of polymer 1 in olive oil was 1.0 mass %.

[0084] The various physical property values ​​of Polymer 1 measured above are shown in Table 1-1 below.

[0085] <Synthesis example 2> Synthesis example 2: R １ =H and CH３ , R ２ =H and CH ３ , R ３ =CH ３ , R ４ =CH ３ Polymer 2 having m=2.0 and n=6.0 Polymer 2 was obtained by the following synthesis method.

[0086] 128 g of methanol and 6.4 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen. The catalyst was then completely dissolved at 80°C while stirring. Next, a mixture of 592 g of glycidol and 1,392 g of propylene oxide was added dropwise at 95°C over 20 hours using a dropping device, followed by stirring for 2 hours. Next, 244 g of potassium hydroxide was charged, and the system was replaced with dry nitrogen. After that, 200 g of methyl chloride was added under pressure at a temperature of 80 to 130°C and reacted for 5 hours. The reaction composition was then removed from the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at a reduced pressure of -0.095 MPa (50 mmHg) and 100°C for 1 hour to remove contained water. After further treatment, filtration was performed to remove the salt produced, and 1,820 g of polymer 2 was obtained. The hydroxyl value of the purified sample taken before the reaction with methyl chloride was 125, indicating that R ２ and R ３ The ratio of methyl groups to hydrogen atoms (CH ３ / H) was found to be 0.57, which means that the hydroxyl group blocking rate of Polymer 2 was 57%.

[0087] As in the case of Polymer 1 described above, various physical property values ​​were determined for the obtained Polymer 2, and the results are shown in Table 1-1 below.

[0088]

[0089] <Compatibility Evaluation> Polymers 1 and 2 synthesized above were mixed with water and various oils at a certain concentration, stirred, and then left to stand for one day, after which their compatibility was examined by visual observation. The results are shown in Table 1-2 below. In Table 1-2, "◯" indicates "compatible" and "×" indicates "insoluble."

[0090]

[0091] 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 polymers 1 and 2 obtained above were prepared, respectively, and the soft focus effect was evaluated. In Comparative Example 1-1, 100% water was used.

[0092] (Evaluation of Soft Focus Effect) The haze value (cloudiness value) was measured using a haze meter manufactured by Murakami Color Research Institute.

[0093] 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, and the haze value was measured again 24 hours later, and the haze values ​​before and after application were compared. The results are shown in Table 1-3.

[0094]

[0095] As is clear from the results in Table 1-3, the aqueous solutions of Examples 1-1 and 1-2 all exhibited higher haze values ​​than those of Comparative Example 1-1.

[0096] That is, it was found that the aqueous solutions of Examples 1-1 and 1-2 containing Polymer 1 and 2, respectively, had a soft focus effect. In other words, it was suggested that Polymer 1 and 2 could each be used as a soft focus agent.

[0097] Examples 1-3 and 1-4 and Comparative Example 1-2 Cosmetic compositions of Examples 1-3 and 1-4 and Comparative Example 1-2 were prepared based on the formulations in Table 1-4. Each of the obtained compositions was applied to a doctor blade (glass plate, film thickness 0.075 mm), and the haze was measured after 24 hours using a haze meter manufactured by Murakami Color Research Institute. The haze of the doctor blade used was also measured as Reference 1. The obtained results are shown in Figure 1.

[0098]

[0099] As is clear from the results in FIG. 1, the compositions of Examples 1-3 and 1-4 containing Polymers 1 and 2, respectively, had significantly higher soft focus effects than the compositions of Comparative Example 1-2 and Reference 1.

[0100] <Evaluation of Soft Focus Effect Using Beaulax Pore Model> Each of the cosmetic compositions of Examples 1-3 and 1-4 and Comparative Examples 1-2 was applied at 2 μL / cm ２ The soft focus effect was evaluated using a Beaulax pore model. The results are shown in Figure 2.

[0101] As is clear from the results in FIG. 2, in terms of the visibility of pores, Example 1-3 made pores the least noticeable, i.e., had the greatest soft focus effect, followed by Example 1-4 and then Comparative Example 1-2.

[0102] [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 polymer 1 and polymer 2 were as shown in the above-mentioned Table 1-1 and Table 1-2.

[0103] 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 polymers 1 and 2 obtained above were prepared, respectively, and the stratum corneum softening effect was evaluated. In Comparative Example 2-1, 100% water was used.

[0104] The stratum corneum softening effect was evaluated as follows.

[0105] <Evaluation of stratum corneum softening effect> The stratum corneum softening effect was evaluated based on the storage modulus (E') of the stratum corneum. A lower storage modulus indicates a softer stratum corneum, i.e., a higher stratum corneum softening effect.

[0106] More specifically, a horizontal-drive dynamic viscoelasticity measuring device, DVA-220 (manufactured by IT Measurement & Control Co., Ltd.), was used. Both ends of a human stratum corneum specimen prepared by trypsin treatment were held horizontally by two clamps installed in the measuring section of the device. The measuring section was configured as a temperature and humidity variable 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. In other words, a smaller E' value indicates a softer stratum corneum. The E' of the stratum corneum treated with each sample was measured to evaluate the effect of each sample on E'.

[0107] 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 FIG.

[0108] As is clear from the results in FIG. 3, it was found that the storage modulus values ​​were significantly lower in Examples 2-1 and 2-2, which used Polymers 1 and 2, respectively, compared to Comparative Example 2-1.

[0109] In other words, these results suggest that both Polymer 1 and Polymer 2 have a significantly high effect of softening the stratum corneum.

Claims

1. A soft focus agent for skin, comprising a polymer (I) having a structure represented by the following formula (1) as an active ingredient, or consisting of the polymer (I): In the formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50, the number average molecular weight of the polymer (I) is 10,000 or less, and the IOB value of the polymer (I) is 0.4 to 1.

8.

2. In the formula (1), A is represented by the following formula (2): In the formula (2), R ４ The soft focus agent according to claim 1 , wherein: is an alkyl group having 1 or 2 carbon atoms.

3. The soft focus agent according to claim 1, wherein the polymer (I) is a random copolymer or a block copolymer.

4. In the formula (1), m is 2 or more, and R １ The soft focus agent according to claim 1 , wherein at least a portion of the groups are methyl groups.

5. In the formula (1), R ２ and R ３ 2. The soft focus agent according to claim 1, wherein at least one of the following is a methyl group.

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

7. A stratum corneum softening agent for skin, comprising a polymer (I) having a structure represented by the following formula (1) as an active ingredient, or consisting essentially of the polymer (I): In the formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50, the number average molecular weight of the polymer (I) is 10,000 or less, and the IOB value of the polymer (I) is 0.4 to 1.

8.

8. In the formula (1), A is represented by the following formula (2): In the formula (2), R ４ The stratum corneum softening agent according to claim 7 , wherein: is an alkyl group having 1 or 2 carbon atoms.

9. The stratum corneum softening agent according to claim 7, wherein the polymer (I) is a random copolymer or a block copolymer.

10. In the formula (1), m is 2 or more, and R １ The stratum corneum softening agent according to claim 7, wherein at least a portion of the groups are methyl groups.

11. In the formula (1), R ２ and R ３ The stratum corneum softening agent according to claim 7 , wherein at least one of the above is a methyl group.

12. A cosmetic composition comprising the stratum corneum softening agent according to any one of claims 7 to 11.

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