Cosmetic composition

Abstract

A cosmetic composition according to the present invention contains a polymer compound having coumarin or a derivative thereof bonded to at least one terminal of a skeleton polymer. The fluidity of the cosmetic composition is reversibly changeable from a first state to a second state by being irradiated with light of a first wavelength, and from the second state to the first state by being irradiated with light of a second wavelength different from the first wavelength.

Description

Cosmetic composition

[0001] The present invention relates to a cosmetic composition.

[0002]

[0003] Conventionally, materials having reversible photoresponsiveness, i.e., the property of reversibly changing their state in response to an external stimulus, have been known. For example, Patent Document 1 describes a polymer compound having coumarin or a derivative thereof bound to at least one end of a backbone polymer, in which the fluidity of the polymer compound can be reversibly changed from a first state to a second state by irradiation with light of a first wavelength, and from the second state to the first state by irradiation with light of a second wavelength different from the first wavelength.

[0003] International Publication No. 2023 / 120191

[0004] Patent Document 1 cites a use of a polymer compound having coumarin or a derivative thereof bound to at least one end of a backbone polymer as a material for a 3D printer, but has not considered providing a cosmetic composition having reversible photoresponsiveness using the polymer compound.

[0005] An object of one aspect of the present invention is to provide a cosmetic composition having reversible photoresponsiveness, using a polymer compound in which coumarin or a derivative thereof is bound to at least one end of a backbone polymer.

[0006] One aspect of the present invention for solving the above-mentioned problems is a cosmetic composition containing a polymer compound in which coumarin or a derivative thereof is bonded to at least one end of a backbone polymer, wherein the fluidity of the cosmetic composition is reversibly changeable from a first state to a second state by irradiating it with light of a first wavelength, and from the second state to the first state by irradiating it with light of a second wavelength different from the first wavelength.

[0007] According to one aspect of the present invention, a cosmetic composition having reversible photoresponsiveness can be provided by using a polymer compound in which coumarin or a derivative thereof is bound to at least one end of a backbone polymer.

[0008] 1 is a graph showing the change in viscoelasticity over time of the composition of Example 1-1. FIG. 2 is a graph showing the change in viscoelasticity over time of the composition of Example 1-2. FIG. 3 is a graph showing the change in viscoelasticity over time of the composition of Example 1-3. FIG. 4 is a graph showing the change in viscoelasticity over time of the composition of Example 1-4. FIG. 5 is a graph showing the change in viscoelasticity over time of the composition of Example 1-5. FIG. 6 is a graph showing the change in viscoelasticity over time of the compositions of Examples 2-1 and 2-2. FIG. 7 is a graph showing the change in viscoelasticity over time when the composition of Example 2-2 is alternately irradiated with light of different wavelengths.

[0009] One embodiment of the present invention is a cosmetic composition comprising a polymer compound having coumarin or a derivative thereof bound to at least one end of a backbone polymer, wherein the fluidity is reversibly changeable from a first state to a second state upon irradiation with light of a first wavelength, and from the second state to the first state upon irradiation with light of a second wavelength different from the first wavelength.

[0010] The present inventors prepared various compositions by combining a polymer compound in which coumarin or a derivative thereof is bonded to at least one end of the backbone polymer with other components such as a solvent, and investigated the photoresponsiveness of the compositions. As a result, they found that a cosmetic composition containing a polymer compound in which coumarin or a derivative thereof is bonded to at least one end of the backbone polymer was obtained, and that the cosmetic composition itself also exhibited reversible photoresponsiveness.

[0011] <Definitions, etc.> In this specification, the term "cosmetic composition" includes cosmetics, quasi-drugs, and personal care products (daily hygiene products). These may be collectively referred to as cosmetics, etc. Furthermore, the term "cosmetic composition" also includes bases used in preparing the above-mentioned cosmetics, etc. In other words, the cosmetic composition according to the present embodiment may be provided as a final product itself, or may be provided as a raw material for preparing a final product. Examples of cosmetics, etc. include skin care products or basic cosmetics such as lotions, emulsions, and serums; makeup cosmetics such as makeup fixers, lipsticks, lip glosses, foundations, blushes, eye shadows, and nail top coats; and hair styling cosmetics such as hairsprays and hair waxes. Examples of personal care products (daily hygiene products) include sunscreens, body creams, body lotions, hair conditioners, and hand creams.

[0012] In this specification, "photoresponsive" refers to a change in properties due to irradiation with light of a specific wavelength, and includes at least a change in fluidity. Note that photoresponsiveness may also include a change in properties such as color due to irradiation with light of a specific wavelength, in addition to a change in fluidity.

[0013] Furthermore, in this specification, "fluidity" may refer to a property that can be measured as a rheological property such as viscosity, elasticity, or viscoelasticity, or a property that can be evaluated by a sensory evaluation of the feel, such as smoothness, softness, or absence of creaking, when touched by a person. When measuring rheological properties, an instrument such as a rheometer can be used. Changes in rheological properties may be measurable as changes in elastic modulus, such as storage modulus G' (Pa) and loss modulus G" (Pa), viscosity, shear rate (shear strength), and thixotropy index. Furthermore, rheological properties may refer to changes in properties that can be visually observed by causing a substance to flow, i.e., by changing the force (including gravity) applied to the composition.

[0014] The term "reversible" refers to the fact that the fluidity can change from a first state to a second state once, and then change from the second state back to the first state again. This change may be at least one round trip between the first state and the second state, and preferably two or more round trips. This reversible change may be, for example, at least one change from the first state to the second state by irradiation with light of a first wavelength, and then one change from the second state to the first state by irradiation with light of a second wavelength. Alternatively, at least one change from the second state to the first state by irradiation with light of a second wavelength, and then one change from the first state to the second state by irradiation with light of the first wavelength.

[0015] Furthermore, the two different states of fluidity, the first and second states, are not particularly limited as long as they are distinguishable from one another. For example, if the first state is a high-fluidity state with higher fluidity and the second state is a low-fluidity state with lower fluidity, they may be distinguishable from one another by the magnitude of an indicator representing fluidity, such as a predetermined value of a measurable rheological property or a predetermined sensory evaluation value. For example, the first state of fluidity may be a liquid state and the second state of fluidity may be a solid state, or the first state of fluidity may be a sol state and the second state of fluidity may be a gel state.

[0016] <Polymer Compound> The polymer compound used in this embodiment has coumarin or a derivative thereof bonded to at least one end of a backbone polymer constituting the main chain, and includes, for example, those described in International Publication No. 2023 / 120191. The fluidity of the polymer compound changes to a first state when irradiated with light of a first wavelength, and changes to a second state when irradiated with light of a second wavelength different from the first wavelength. This change in fluidity of the polymer compound is due to the molecular structure of the polymer compound itself and involves the formation and cleavage of intermolecular bonds, specifically covalent bonds. For example, by irradiating a crosslinkable polymer compound in an uncrosslinked state with light of the first wavelength, the crosslinkable polymer compounds bond to each other to form a crosslinked polymer compound crosslinked product (also simply referred to as a crosslinked product). Irradiating the crosslinked polymer compound with light of the second wavelength cleaves the bonds within the crosslinked polymer compound, forming a crosslinked polymer compound. The formation and cleavage of such bonds between molecules is achieved by the formation and cleavage of bonds between coumarin or a derivative thereof bonded to the end of the backbone polymer.

[0017] In this specification, unless otherwise specified, the term "polymer compound" includes a crosslinkable polymer compound and / or a crosslinked polymer compound obtained by crosslinking a crosslinkable polymer compound. The ratio of the crosslinkable polymer compound to the crosslinked polymer compound in the cosmetic composition may vary depending on the light irradiation conditions, such as the wavelength of light, the intensity of light, and the irradiation time.

[0018] The backbone polymer constituting the polymer compound is not particularly limited, but it is preferable that the backbone polymer alone (before the introduction of coumarin or a derivative thereof) has high fluidity at room temperature, and is preferably in a liquid or sol state.

[0019] Examples of the backbone polymer include polysiloxane-based polymers, polyacrylate-based polymers, polymethacrylate-based polymers, polystyrene-based polymers, polyethylene-based polymers, polyamide-based polymers, polyester-based polymers, and polyurethane-based polymers. Of these, polysiloxane-based polymers are preferred. Examples of polysiloxane-based polymers include polydimethylsiloxane (PDMS), polymethylphenylsiloxane, and polymethylhydrogensiloxane, of which polydimethylsiloxane (PDMS) is preferred. Note that one or a combination of two or more of the above polymers may be used as the backbone polymer.

[0020] The number average molecular weight of the backbone polymer may be preferably 500 or more and 100,000 or less, more preferably 1,000 or more and 50,000 or less. The backbone polymer may also have a glass transition temperature of preferably -150°C or more and 25°C or less, more preferably -120°C or more and 0°C or less.

[0021] Furthermore, the skeletal polymer preferably has a branched structure, and more preferably has a structure in which multiple branched chains (arms) extend from a central core. The central core preferably contains a carbon atom or a benzene ring. In particular, a benzene ring as the central core is preferred because it stabilizes the structure of the skeletal polymer, and therefore the structure of the polymer compound, thereby enabling a more reliable change in fluidity between the first state and the second state. Furthermore, the number of branched chains attached to one central core (the number of arms extending from the central core) is preferably 2 to 8 (i.e., the skeletal polymer has a 2- to 8-branched structure), more preferably 2 to 5 (i.e., the skeletal polymer has a 2- to 5-branched structure), or more preferably 3 to 6 (i.e., the skeletal polymer has a 3- to 6-branched structure). It is even more preferred that the number of branched chains attached to the central core in the skeletal polymer is 3 (i.e., the skeletal polymer has a 3-branched structure).

[0022] The backbone polymer portion in the polymer compound according to this embodiment can have various structures, for example, a structure in which a polysiloxane structure is bonded to a central core such as a hydrocarbon group or a siloxane structure. The structure of the backbone polymer portion can be represented by formula (a-1).

[0023] In formula (a-1), Z is the central nucleus. Z may be a hydrocarbon group having a valence of n1 or a siloxane structure having a valence of n1. Each PS1 is independently a polysiloxane structure. n1 is 1 or more and 6 or less. # indicates the bonding position to a partial structure containing coumarin or a derivative thereof.

[0024] PS1 may be a chain group having one end bonded to Z and the other end bonded to coumarin or a coumarin derivative. The number of siloxane repeating units constituting the polysiloxane structure contained in PS1 may be 1 or more and 150 or less. The siloxane repeating units constituting the polysiloxane structure contained in PS1 are not particularly limited, but examples thereof include the following:

[0025]

[0026] PS1 may contain one type of polysiloxane repeating unit alone or a combination of two or more types.

[0027] PS1 may further contain a hydrocarbon chain. ２ - represents an oxy (-O-) group, an ester (-CO-O-) group, or -SiR ２ - (wherein R ２ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms).

[0028] When Z is a hydrocarbon group having a valence of n1, at least one —CH ２ - is an oxy (-O-) group, an ester (-CO-O-) group, or -SiR ２ - (where R ２are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms), and at least one hydrogen of the hydrocarbon group is —SiR ３、 or halogen (wherein R ３ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms. The number of carbon atoms contained in Z may be 1 to 20. More specifically, Z is an aromatic hydrocarbon group or an aliphatic hydrocarbon group, preferably an aromatic hydrocarbon group, and particularly preferably a benzene ring. Specific examples of the structure of the backbone polymer moiety when Z is a hydrocarbon group having a valence of n1 are shown below.

[0029] In particular, when Z, which forms the central core, is a benzene ring, the structure of the backbone polymer, and therefore the structure of the polymer compound according to this embodiment, is stabilized, thereby enabling a more reliable change in flow characteristics between the first state and the second state, which is preferable. Furthermore, the number of branched chains bonded to one central core (the number of arms extending from the central core) is preferably 2 to 10, more preferably 2 to 8, even more preferably 2 to 5, or even 3 to 6. It is even more preferable that the number of branched chains bonded to the central core in the backbone polymer is 3 (i.e., the backbone polymer has a three-branched structure).

[0030] Furthermore, the backbone polymer is preferably a polydimethylsiloxane having a three-branched structure with a benzene ring as the central nucleus, more specifically, a polydimethylsiloxane represented by the formula (1):

[0031] More preferably, the polydimethylsiloxane is a three-armed star polydimethylsiloxane (PDMS) represented by formula (1), in which n is 1 to 150, and all three branched chains have the same structure. Note that the polydimethylsiloxane having hydrosilane ends at the branched chains as described above is sometimes referred to as a hydrosilane-terminated three-armed star polydimethylsiloxane.

[0032] In another embodiment, when Z is a siloxane residue having a valence of n1, that is, when Z is a siloxane residue having n1 bonds, the siloxane residue may be a residue of silicic acid containing one Si, a linear siloxane, a cyclic siloxane, or a cage siloxane. Specific examples of when Z is a siloxane residue are shown below.

[0033]

[0034] In the above formula, R ４ are each independently a halogen atom, a nitro group, a hydroxy group, a phenyl group, or an alkyl group (the alkyl group preferably has from 1 to 3 carbon atoms, and may be substituted with a halogen atom, a nitro group, or a hydroxy group).

[0035] The polymer compound in this embodiment has coumarin or a derivative thereof bound to at least one end of the above-mentioned backbone polymer, and has a group derived from coumarin or a derivative thereof (hereinafter also referred to as a coumarin moiety). While it is sufficient for coumarin or a derivative thereof to be bound to at least one end of the backbone polymer, it is preferable for coumarin or a derivative thereof to be bound to all ends of the backbone polymer, since this increases the number of crosslinking points between molecules of the crosslinkable polymer compound. Furthermore, by binding coumarin or a derivative thereof to the end of the backbone polymer rather than as a side chain, it is possible to prevent the coumarin moieties from aggregating and causing phase separation, etc.

[0036] When the backbone polymer has a branched structure, coumarin or a derivative thereof is bonded to at least one end of the branched chain of the backbone polymer. Coumarin or a derivative thereof may be bonded to preferably 50% or more, more preferably 60% or more, and even more preferably 80% or more of the branched chains of the backbone polymer. It is also preferable that coumarin or a derivative thereof is bonded to all of the ends of the branched chains of the backbone polymer.

[0037] The coumarin derivative is not particularly limited as long as it does not interfere with the reversible change in the flow properties of the polymer compound upon irradiation with light of different wavelengths as described above in this embodiment. The coumarin derivative may be, for example, a coumarin into which a substituent has been introduced. In this case, one to three hydrogen atoms in one coumarin moiety may be substituted with a substituent. The substituent may be, for example, one or more groups selected from the group consisting of a halogen atom, a nitro group, a hydroxy group, and an alkyl group (the alkyl group preferably has one to three carbon atoms and may be substituted with a halogen atom, a nitro group, or a hydroxy group). Therefore, the polymer compound in this embodiment may be, in other words, a polymer compound having a substituted or unsubstituted coumarin group (coumaryl group) at the end of a backbone polymer.

[0038] More specifically, the coumarin derivative can be represented by the following formula (a-2).

[0039] In formula (a-2), R ａ are each independently a halogen atom, a nitro group, a hydroxy group, a phenyl group, or an alkyl group (the alkyl group preferably has 1 to 3 carbon atoms and may be substituted with a halogen atom, a nitro group, or a hydroxy group). ａ is a group in which any H in coumarin is substituted, and the position and number of the substituted H are not particularly limited. ａ When R is a hydroxy group or contains a hydroxy group, it is preferable from the viewpoint of reactivity that the hydroxy group is further bonded to another substituent. The substituent is not limited as long as it is a commonly used one. Examples of the substituent include a benzyl group, a silyl group, an acetyl group, and a trityl group. ａ But methylene (-CH ２ -), at least one of them is dimethylsilyl (-Si(CH3) ２ It may be replaced by -), oxy (-O-), or carbonyl (-C=O-).

[0040] Specific examples of coumarin derivatives include the following compounds.

[0041]

[0042] An example of the partial structure containing a coumarin derivative that is bonded to the above-mentioned backbone polymer portion is a structure represented by the following formula (a-3).

[0043] In formula (a-3), * indicates the bonding position to # in formula (a-1). L may be a single bond or a hydrocarbon chain. When L is a hydrocarbon chain, —CH ２ - may be replaced with an oxy (-O-) group or an ester (-CO-O-) group, and at least one hydrogen in the hydrocarbon chain is replaced with -SiR ３、 or halogen (wherein R ３ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, and the number of carbon atoms contained in L is 1 to 20. ａ is R in formula (a-2) ａ that is, each independently represents a halogen atom, a nitro group, a hydroxy group, a phenyl group, or an alkyl group (the alkyl group preferably has 1 to 3 carbon atoms, and may be substituted with a halogen atom, a nitro group, or a hydroxy group).

[0044] Examples of polymer compounds include those represented by formula (2):

[0045] [wherein R each independently represents hydrogen or an alkyl group, and n, m, and p each independently represent an integer of 1 or more and 150 or less]. Note that the compound of the above formula is an uncrosslinked compound, i.e., a crosslinkable polymer compound, but the polymer compound includes the compound of the above formula, a crosslinked product obtained by crosslinking the compound of the above formula, or both.

[0046] In formula (2), preferably 50% or less of R in one branched chain are hydrogen, more preferably 10% or less, and even more preferably all of R are alkyl groups. Furthermore, when R is an alkyl group, it is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, more preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and even more preferably a linear alkyl group having 1 to 3 carbon atoms. Furthermore, it is preferable that n, m, and p are the same, and it is even more preferable that the three branched chains branching from the central benzene ring have the same structure. Note that the above-mentioned compound having coumarin bonded to the end of the branched chain is sometimes called a terminal coumarin-type three-arm star polydimethylsiloxane.

[0047] The number average molecular weight of the crosslinkable polymer compound (uncrosslinked polymer compound) may be preferably 500 or more and 100,000 or less, more preferably 1,000 or more and 50,000 or less. When compared under the same irradiation conditions (even when the first wavelength and the second wavelength are the same), the tendency of the change in viscoelasticity may differ depending on the number average molecular weight of the crosslinkable polymer compound. Therefore, the viscoelasticity of the polymer compound can be controlled by changing the molecular weight.

[0048] <State Change of Polymer Compounds by Irradiation with Light> The following provides a more detailed explanation of the structural change of polymer compounds by irradiation with light of different wavelengths. In this explanation, a three-arm star-shaped polydimethylsiloxane (PDMS) having a coumarin group at the end of each branched chain is used as an example. In formula (3), the upper row shows the uncrosslinked compound in the first state, i.e., the crosslinkable polymer compound, and the lower row shows the compound in the second state, in which the coumarin moieties are bonded to each other and crosslinked between molecules, i.e., the crosslinked polymer compound. In formula (3), the first state is a high-fluidity state with high fluidity, and the second state is a low-fluidity state with low fluidity.

[0049]

[0050] In the above formula, n is an integer of 1 or more and 150 or less, and the three branched chains may have the same structure. As shown in the above formula, irradiation with light of the first wavelength crosslinks molecules of the crosslinkable polymer compound to form a network structure, thereby causing a change from a first state with high fluidity to a second state with low fluidity. Furthermore, irradiation with light of the second wavelength cleaves the crosslinks, causing a change from the second state with low fluidity to the first state with high fluidity. Both the crosslinking reaction from the first state to the second state and the crosslink cleavage reaction from the second state to the first state can be carried out under conditions conventional in the art. A reaction-accelerating agent can be used in both the reaction from the first state to the second state and the reaction from the second state to the first state.

[0051] The light irradiated to change the state of the polymer compound is preferably ultraviolet light, both at a first wavelength and a second wavelength different from the first wavelength. Here, the first wavelength may be in the range of 300 nm to 390 nm, preferably 350 nm to 380 nm, and more preferably 360 nm to 370 nm. The second wavelength may be in the range of 200 nm to 290 nm, preferably 230 nm to 270 nm, and more preferably 250 nm to 270 nm. Furthermore, it is preferable that the first wavelength be 365 nm and the second wavelength be 254 nm. Thus, in this embodiment, the first wavelength for causing a change from a high fluidity state to a low fluidity state is greater than the second wavelength.

[0052] Furthermore, once the polymer compound of this embodiment is irradiated with light, it can maintain the state of flow characteristics after the change caused by the irradiation even after the light irradiation is stopped. That is, if the polymer compound changes from the first state to the second state by irradiation with light of the first wavelength, the flow characteristics of the second state can be maintained even after the irradiation with light of the first wavelength is stopped, as long as there is no stimulus to cause a change to the second state, such as irradiation with light of the second wavelength. Furthermore, if the polymer compound changes from the second state to the first state by irradiation with light of the second wavelength, the flow characteristics of the first state can be maintained even after the irradiation with light of the second wavelength is stopped, as long as there is no stimulus to cause a change to the first state, such as irradiation with light of the first wavelength. Specifically, after crosslinks between molecules are formed by irradiation with light of the first wavelength, the formed crosslinks are maintained even after the irradiation is stopped. However, if the crosslinks between molecules are cleaved by irradiation with light of the second wavelength, the cleaved crosslinks remain cleaved even after the irradiation is stopped.

[0053] <Cosmetic Composition> The cosmetic composition according to this embodiment is a composition containing the above-described polymer compound in which coumarin or a derivative thereof is bonded to at least one end of the backbone polymer, and another component. While the photoresponsiveness of the polymer compound has been described above, the photoresponsiveness of the polymer compound is reflected in the cosmetic composition according to this embodiment. In other words, the cosmetic composition itself is reversibly changeable from a first state to a second state when irradiated with light of a first wavelength, and from the second state to the first state when irradiated with light of a second wavelength different from the first wavelength.

[0054] The other component to be combined with the cosmetic composition is not particularly limited as long as it is a component that can be used in cosmetic applications. Since cosmetic compositions are typically applied to human skin, the other component to be combined is preferably a component that is easy to apply (has fluidity that allows for easy application by conventional methods). Furthermore, the other component is preferably a component that, when combined with an uncrosslinked polymer compound, can maintain the entire cosmetic composition in a liquid or sol state. Furthermore, the other component is preferably a solvent that can dissolve and / or disperse the crosslinkable polymer compound. The solvent may be an aqueous solvent and / or an oily solvent. However, since oily solvents easily dissolve the above-mentioned polymer compounds, it is preferable that the cosmetic composition contains at least an oily solvent, since this allows the polymer compound to be homogeneously present in the cosmetic composition or in the oil phase of the cosmetic composition.

[0055] Cosmetic compositions can be provided in various forms depending on the type of other component(s) combined. For example, if a cosmetic composition contains an oily solvent as a separate component, the cosmetic composition can be provided as an oil-based composition. An oil-based composition is a composition that contains substantially no aqueous components or no aqueous components at all, and therefore the separate component is mainly an oily solvent. On the other hand, if a cosmetic composition contains an oily solvent and an aqueous solvent as separate components, the cosmetic composition can be provided as an emulsion-based composition. The emulsion-based composition may be an oil-in-water type or a water-in-oil type. When the cosmetic composition is an emulsion-based composition, it is preferable that a component with emulsifying properties, such as a surfactant, be added.

[0056] The cosmetic composition may be a homogeneous composition in which the polymer compound is dissolved and / or dispersed throughout the composition, or a phase-separated composition in which the polymer compound or a phase containing the polymer compound is visually recognized as being phase-separated. A phase-separated composition may be homogenized by stirring or the like before application. Therefore, when this embodiment is an emulsion-based composition, the emulsion-based composition may be a homogeneous composition or a phase-separated composition.

[0057] In the cosmetic composition, the polymer compound and the other component may be blended in any ratio; that is, the content of the polymer compound in the cosmetic composition may be any amount. The content of the polymer compound having a backbone polymer bonded to at least one end thereof is preferably 0.1% by mass or more and 80% by mass or less, more preferably 0.5% by mass or more and 70% by mass or less, and even more preferably 1% by mass or more and 60% by mass or less, relative to the total amount of the cosmetic composition. By setting the content of the polymer compound to 0.1% by mass or more, the photoresponsiveness of the cosmetic composition can be more significantly exhibited. For example, when the storage modulus G' (Pa) or the loss modulus G" (Pa) is compared between a high fluidity state (first state) and a low fluidity state (second state), the difference becomes more significant. Furthermore, by setting the content of the photoresponsive compound to 80% by mass or less, the ease of handling as a cosmetic composition can be improved.

[0058] When a cosmetic composition contains an oily solvent, the oily solvent is not particularly limited, except for oily solvents commonly used as components of cosmetic compositions that may interfere with the photoresponsiveness of the cosmetic composition by, for example, absorbing irradiated light. However, when the cosmetic composition is an oil-based homogeneous composition, it is preferable to contain a low-molecular-weight, non-polar solvent from the viewpoint of being able to well dissolve a polymeric compound having coumarin or a derivative thereof bonded to at least one end of the backbone polymer. Note that the term "low-molecular-weight" in this specification does not necessarily have the general meaning, but may vary depending on the solvent, and may refer to the molecular weight of the same solvent type (e.g., silicone oils, hydrocarbon oils). Preferably, the low-molecular-weight solvent is a volatile solvent.

[0059] Examples of low-molecular-weight nonpolar solvents include one or more of silicone oil and hydrocarbon oil. The silicone oil is preferably a volatile silicone oil. The silicone oil may be a linear or branched polysiloxane, or a cyclic siloxane, but a linear polysiloxane or a cyclic siloxane is preferred because it can better dissolve the above-mentioned polymer compound. In this specification, a linear polysiloxane refers to a structure in which a hydrogen atom or a methyl group is bonded to a main skeleton that is a siloxane bond (-Si-O-Si-).

[0060] Specific examples of silicone oils include polydimethylsiloxane (PDMS, dimethicone), polymethylhydrosiloxane (PMHS), cyclomethicone, etc. Among these, polydimethylsiloxane (PDMS, dimethicone) is preferred. In addition, when the low-molecular nonpolar solvent is silicone oil, the kinematic viscosity (mm ２ The molecular weight (molecular weight / s or cs) is not particularly limited and may be preferably 0.1 to 100, more preferably 0.5 to 50, at 25° C. The number average molecular weight of the silicone oil may be preferably 100 to 2,000, more preferably 200 to 1,000.

[0061] Furthermore, the hydrocarbon oil is preferably a saturated aliphatic hydrocarbon. Furthermore, a volatile hydrocarbon is preferable. The number of carbon atoms in the hydrocarbon oil used as the oil-based solvent may be preferably 5 to 30, more preferably 10 to 20. The hydrocarbon oil may be a straight-chain hydrocarbon or a branched hydrocarbon. However, even if it is a straight-chain hydrocarbon, the group constituting the branched chain preferably has one carbon atom (a methyl group). Specific examples of hydrocarbon oils include isododecane, isohexadecane, hydrogenated polyisobutene, and olefin oligomers (α-olefin oligomers). The molecular weight of the hydrocarbon oil may be preferably 50 to 500, more preferably 100 to 300.

[0062] The low molecular weight nonpolar solvents may be used alone or in combination of two or more thereof, for example, a combination of multiple silicone oils, a combination of multiple hydrocarbon oils, or a combination of a silicone oil and a hydrocarbon oil.

[0063] Furthermore, a low molecular weight nonpolar solvent may be combined with a solvent that is not a low molecular weight nonpolar solvent, and mixed with a polar solvent, such as a polar oil. The polar oil to be combined with the low molecular weight nonpolar solvent may be, for example, a polar silicone oil, a polar hydrocarbon oil, an ester oil, or the like. The ester oil may be, for example, a monohydric alcohol fatty acid ester or a polyhydric alcohol fatty acid ester, specifically, cetyl ethylhexanoate, pentaerythrityl tetraethylhexanoate, or the like.

[0064] In addition, it is preferable that the oily solvent has the same or similar structure as the backbone polymer of the photoresponsive compound, since this increases the solubility of the photoresponsive compound in the oily solvent. For example, if the backbone polymer of the photoresponsive compound is polydimethylsiloxane (PDMS), it is preferable to use polydimethylsiloxane (PDMS) or a silicone oil having polydimethylsiloxane (PDMS) as the main backbone as the oily solvent.

[0065] When the cosmetic composition of the present embodiment contains an oily solvent, the content of the polymer compound having coumarin or a derivative thereof bonded to at least one end of a backbone polymer may be preferably 50 parts by mass or more and 200 parts by mass or less, more preferably 60 parts by mass or more and 150 parts by mass or less, and even more preferably 75 parts by mass or more and 125 parts by mass or less, based on 100 parts by mass, regardless of the form of the composition (i.e., oil-based composition, emulsion-based composition, etc.).

[0066] The content of the low molecular weight nonpolar solvent in the oily solvent may be preferably 20% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more, based on the total amount of the oily solvent. It is also preferable that the oily solvent consists of a low molecular weight nonpolar solvent or essentially consists of a low molecular weight nonpolar solvent. The expression "essentially consisting of" a predetermined component means that the predetermined component is contained in an amount of 98% by mass or more, preferably 99% by mass or more, and more preferably 99.5% by mass or more.

[0067] Furthermore, the content of the silicone oil in the oily solvent may be preferably 20% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more, based on the total amount of the oily solvent. Furthermore, it is preferable that the oily solvent consists of silicone oil or essentially consists of silicone oil.

[0068] When the cosmetic composition contains an aqueous solvent, the aqueous solvent may be purified water, ion-exchanged water, tap water, water-soluble alcohol, etc. Examples of water-soluble alcohols include lower alcohols, polyhydric alcohols, polyhydric alcohol polymers, alcohol alkyl ethers, alcohol ether esters, glycerin monoalkyl ethers, sugar alcohols, and derivatives thereof.

[0069] Furthermore, the cosmetic composition according to the present embodiment may contain other components besides the oily solvent and the aqueous solvent, as appropriate, in amounts that do not inhibit the photoresponsiveness of the cosmetic composition, depending on the form of the cosmetic composition portion and the type and function of the cosmetic, etc. Examples of other components besides the oily solvent and the aqueous solvent include emulsifiers (including surfactants), surface-treated or untreated inorganic powders (including UV scattering agents), resin particles, solid oil components, preservatives, thickeners, moisturizers, film-forming aids, etc.

[0070] When the cosmetic composition is an emulsion-based composition, it is preferable for it to contain a surfactant as an emulsifier. In this case, the surfactant used is not particularly limited as long as it is one used in the field of cosmetics, etc., but a nonionic surfactant is preferable. Examples of nonionic surfactants that can be used include ester oils and their derivatives. Specific examples include sorbitan fatty acid esters such as sorbitan sesquiisostearate, sorbitan sesquioleate, sorbitan isostearate, and sorbitan palmitate; polyethylene glycol fatty acid esters such as PEG-8 diisostearate and PEG-10 diisostearate; and polyglycerin fatty acid esters such as polyglyceryl-2 diisostearate and polyglyceryl-2 triisostearate. Furthermore, when the backbone polymer of the photoresponsive compound is polydimethylsiloxane (PDMS, dimethicone) or a derivative thereof, and / or the oily solvent is polydimethylsiloxane (PDMS, dimethicone) or a derivative thereof, silicone-based surfactants are also preferable because they exhibit particularly high emulsifying properties. The surfactants can be used alone or in combination of two kinds.

[0071] Specific Use Examples As described above, the cosmetic composition according to the present embodiment exhibits a change in fluidity upon irradiation with light, and therefore the cosmetic composition can be suitably used, for example, as a makeup fixer. A makeup fixer is a cosmetic product that is applied or sprayed onto the face after makeup application to form a thin film on the surface of the makeup, thereby maintaining the makeup in the state it was in immediately after application. In this case, the cosmetic composition according to the present embodiment is stored in a light-blocking container in a highly fluid state (uncrosslinked state). At the time of use, the highly fluid cosmetic composition is removed from the container and applied or sprayed to form a film. The applied cosmetic composition is then exposed to sunlight, for example, outdoors. Here, sunlight typically contains many components with a wavelength of 300 nm or more and 390 nm or less, which is the preferred range of the first wavelength, i.e., contains many components that reduce the fluidity of the cosmetic composition. Therefore, exposing the film to outdoor sunlight facilitates the crosslinking reaction of the polymer compounds contained in the cosmetic composition, reducing the fluidity of the cosmetic composition and hardening the film, ensuring that it is securely adhered to the makeup.

[0042] Then, even if the user moves from outdoors to indoors and the exposure to ultraviolet light substantially ceases, the fluidity of the cosmetic composition is maintained, and the effect of maintaining the makeup is thus sustained. Furthermore, when it is desired to remove makeup, the makeup fixer coating can be brought into a highly fluid state by irradiating the user with light having a wavelength of 200 nm or more and 290 nm or less, which is a preferred second wavelength range, and the makeup can be easily removed together with the makeup fixer.

[0072] As described above, the cosmetic composition according to the present embodiment does not simply form a film of the cosmetic composition on the skin, but rather the film can be cured by irradiation with light, which effectively prevents moisture from scattering from the face and allows the composition to be used as a moisturizing cosmetic.

[0073] The cosmetic composition according to the present embodiment can be irradiated with light at a temperature of 0° C. or higher and 100° C. or lower, and is preferably irradiated at room temperature (5° C. or higher and 35° C. or lower). The intensity of the irradiated light is 0.2 mW / cm. ２ 40mW / cm or more ２This range of light intensity also includes the intensity of ultraviolet light from the sun outdoors.

[0074] <Synthesis of Polymer Compound> A polymer compound having a coumarin group at its terminal was synthesized as follows.

[0075] Trifunctional silanol (I ３ ) (300 mg), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (209 mg), and tetrahydrofuran (THF) (27 mL) were mixed, and a THF solution (36 mL) of hexamethylcyclotrisiloxane (D3) (30 g) was added and stirred at 25°C. After 4 hours, pyridine (14.5 mL) and chlorodimethylsilane (6.54 mL) were added, in that order, and the mixture was stirred for an additional 17 hours. The reaction mixture was poured into excess water / hexane, and the hexane layer was washed with water, dried over sodium sulfate, and concentrated. The resulting oily crude product was washed with methanol and acetone, and chloroform was added to form a homogeneous solution. The volatile components were then distilled off under reduced pressure to yield a colorless, oily hydrosilane-terminated three-arm star polydimethylsiloxane (hydrosilane-terminated three-arm star PDMS). The yield was 20.7 g.

[0076] Furthermore, a coumarin moiety was introduced into the end of the branched chain of the hydrosilane-terminated three-arm star-shaped PDMS as follows.

[0077]

[0078] The above hydrosilane-terminated three-arm star PDMS (18.0 g), 7-allylcoumarin (1.66 g), Karstedt's catalyst (35 μL), and THF (25 mL) were mixed and stirred under reflux for 7 hours. The reaction mixture was concentrated and washed with methanol and acetone, and the volatile components were distilled off under reduced pressure to obtain 9.9 g of the oily coumarin-terminated three-arm star PDMS (hereinafter referred to as PDMS-coumarin) shown in the formula above. GPC analysis revealed that the number-average molecular weight Mn(RI) of the above PDMS-coumarin was 39,200 (D = 2.14).

[0079] <Experiment I> 1.0 g of the obtained polymer compound (PDMS-coumarin) was mixed with the same mass of each of the oily solvents shown in Table 1 at 25°C to prepare compositions of Examples 1-1 to 1-5.

[0080] *1: KF-96L-1.5CS: Manufactured by Shin-Etsu Chemical Co., Ltd. *2: KF-96A-6CS: Manufactured by Shin-Etsu Chemical Co., Ltd.

[0081] The viscoelasticity of each composition was measured using a rotational rheometer (MCR-102, manufactured by Anton Paar). Specifically, a sample was applied to the surface of the glass lower plate of the rotational rheometer to a thickness of 0.1 mm, and a parallel plate (diameter 12 mm) was placed on it and rotated at a frequency of 1 Hz. After 120 seconds had elapsed from the start of rotation, a wavelength of 365 nm (150 mW / cm) was applied from the underside of the lower plate. ２ ) for 120 minutes, and the storage modulus G' (Pa) and loss modulus G" (Pa) were measured over time. Graphs of the measurement results are shown in FIGS. 1 to 5.

[0082] The change in viscoelasticity of the composition of each example was evaluated as follows. The evaluations are shown in Table 1. ◯: The change in viscoelasticity due to light irradiation was confirmed both in the measurement data and with the naked eye. △: The change in viscoelasticity due to light irradiation was not confirmed with the naked eye, but was confirmed in the measurement data. ×: The change in viscoelasticity due to light irradiation was not confirmed at all in the measurement data or with the naked eye.

[0083] As shown in FIGS. 1 to 5, it was found that the composition obtained by mixing PDMS-coumarin with an oily solvent such as hydrocarbon oil, ester oil, or silicone oil can change state upon irradiation with light.

[0084] <Experiment 2> Using the above PDMS-coumarin, cosmetic compositions were prepared according to the formulations shown in Table 2. Both the compositions of Example 2-1 and Example 2-2 were prepared as makeup fixers to be used in the final stage of makeup application, and Example 2-1 is an example.

[0085] *3: KF-7312K: manufactured by Shin-Etsu Chemical Co., Ltd.

[0086] The viscoelasticity of the compositions of Examples 2-1 and 2-2 was measured using a rotational rheometer (MCR-102, manufactured by Anton Paar). Specifically, assuming the drying state of the volatile components after application, each composition was dried under reduced pressure at 40°C overnight. A sample was applied to the surface of the glass lower plate of the rotational rheometer to a thickness of 0.1 mm. A parallel plate (diameter 12 mm) was then placed on the plate and rotated at a frequency of 1 Hz. After 120 seconds had elapsed since the start of rotation, a 365 nm (150 mW / cm) wavelength light was applied from the underside of the lower plate. ２ ) for 120 minutes, and the storage modulus G' (Pa) and loss modulus G" (Pa) were measured over time. The graph of the measurement results is shown in FIG.

[0087] As shown in FIG. 6, it was found that the composition of Example 2-1 containing PDMS-coumarin underwent a significant change in viscoelasticity upon light irradiation. On the other hand, the composition of Example 2-2 not containing PDMS-coumarin showed no change in viscoelasticity upon light irradiation. Furthermore, when Examples 2-1 and 2-2 were compared, it was found that the viscoelasticity of the compositions, i.e., the storage modulus G' and the loss modulus G", were both roughly the same initially (before light irradiation), but that a significant difference arose after light irradiation, as shown in FIG. 6.

[0088] Furthermore, for the composition of Example 2-1, the wavelength was 365 nm (150 mW / cm ２ ) ultraviolet light and wavelength 254 nm (17 mW / cm ２ The storage modulus G' (Pa) and loss modulus G" (Pa) were measured over time by alternately irradiating the specimen with ultraviolet light of 365 nm wavelength (150 mW / cm) from the bottom of the lower plate. The measurements were performed using the same rotational rheometer as above, and the operating conditions of the apparatus were also the same. The ultraviolet light was irradiated from the bottom of the lower plate with ultraviolet light of 365 nm wavelength (150 mW / cm) from the bottom of the lower plate, starting 120 seconds after the start of rotation. ２ After 300 seconds of irradiation with ultraviolet light of wavelength 254 nm (17 mW / cm), the irradiation was stopped and 300 seconds of no irradiation were allowed. ２ ) was started, and then irradiation was stopped after 300 seconds, and then 300 seconds passed without irradiation, and this cycle was repeated six times. The graph of the measurement results is shown in FIG.

[0089] As shown in Figure 7, the composition of Example 2-1 containing PDMS-coumarin exhibited a reversible change in state, in which its viscoelasticity increased when irradiated with light of a specific wavelength, and decreased when irradiated with light of a different wavelength from the specific wavelength. Thus, it was found that PDMS-coumarin exhibits reversible photoresponsiveness even in the form of a composition prepared by mixing with a solvent.

[0090] Although the present invention has been described above based on specific embodiments and examples, these embodiments and examples are presented only as examples, and the present invention is not limited to the above embodiments and examples. Various changes, modifications, substitutions, deletions, additions, combinations, etc. are possible within the scope of the disclosure of the present invention.

[0091] This application claims priority based on Japanese Patent Application No. 2024-074430, filed May 1, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A cosmetic composition containing a polymeric compound in which coumarin or a derivative thereof is bonded to at least one end of a backbone polymer, wherein the fluidity of the cosmetic composition is reversibly changeable from a first state to a second state when irradiated with light of a first wavelength, and from the second state to the first state when irradiated with light of a second wavelength different from the first wavelength.

2. The cosmetic composition according to claim 1, which is an oil-based composition further containing an oily solvent.

3. The cosmetic composition according to claim 1, which is an emulsion composition containing an oily solvent and an aqueous solvent.

4. The cosmetic composition according to claim 2 or 3, wherein the oily solvent comprises a non-polar solvent.

5. The cosmetic composition according to claim 4, wherein the non-polar solvent is one or more of a silicone oil and a hydrocarbon oil.

6. The cosmetic composition according to claim 2 or 3, wherein the content of the polymer compound is 0.1% by mass or more and 80.0% by mass or less relative to the total amount of the polymer compound and the oily solvent.

7. The cosmetic composition according to claim 1 or 2, wherein the first wavelength is 300 nm or more and 390 nm or less, and the second wavelength is 200 nm or more and 290 nm or less.

8. The cosmetic composition according to claim 1 or 2, wherein the backbone polymer is polysiloxane.

9. The cosmetic composition according to claim 1 or 2, wherein the backbone polymer has a number average molecular weight of 1,000 or more and 100,000 or less.

10. The cosmetic composition according to claim 1 or 2, wherein the polymer compound comprises a backbone polymer moiety represented by formula (a-1) and a moiety containing an unsubstituted coumarin group or a coumarin derivative represented by formula (a-3) bonded together. [In formula (a-1), Z represents a hydrocarbon group having 1 to 20 carbon atoms and a valence of n1, or a siloxane structure having a valence of n1, and each PS1 independently represents a polysiloxane structure and may further include a hydrocarbon chain, and at least one —CH ２ - is an oxy (-O-) group, an ester (-CO-O-) group, or -SiR ２ -, and R ２ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, n1 is 1 to 6, and # indicates the bonding position to * in formula (a-3). [In formula (a-3), * indicates the bonding position to # in formula (a-1), L is a single bond or a hydrocarbon chain having 1 to 20 carbon atoms, and when L is the hydrocarbon chain, at least one —CH ２ - may be replaced with an oxy (-O-) group or an ester (-CO-O-) group, and at least one hydrogen in the hydrocarbon chain is replaced with -SiR ３、 or halogen, R ３ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms; R ａ are each independently a halogen atom, a nitro group, a hydroxy group, a phenyl group, a benzyloxyl group, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, a linear alkoxy group having 1 to 6 carbon atoms, a branched alkoxy group having 3 to 6 carbon atoms, or a cyclic alkoxy group having 3 to 6 carbon atoms, and the alkyl group or alkoxy group may be substituted with a halogen atom, a nitro group, or a hydroxy group; R ａ But methylene (-CH ２ -), at least one of them is dimethylsilyl (-Si(CH3) ２ -), oxy (-O-), or carbonyl (-C=O-).

11. Z in the formula (a-1) is an aromatic hydrocarbon group having 20 or less carbon atoms and a valence of n1, and at least one —CH ２ - is an oxy (-O-) group, an ester (-CO-O-) group, or -SiR ２ -, and at least one hydrogen in the hydrocarbon group may be replaced by -SiR ３、 or halogen, R ２ and R ３ The cosmetic composition according to claim 10, wherein each of the groups independently represents hydrogen or an alkyl group having 1 to 3 carbon atoms.

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