Cosmetic composition

Abstract

A cosmetic composition containing a high-molecular compound having coumarin or a derivative thereof bound to at least one end of a backbone high-molecule, the flowability of the cosmetic composition being capable of changing from a first state to a second state by irradiation of light of a first wavelength, and being capable of reversibly changing from the second state to the first state by irradiation of light of a second wavelength different from the first wavelength.

Description

Technical Field

[0001] This invention relates to a cosmetic composition. Background Technology

[0002] Traditionally, materials with reversible photoresponsiveness are known, meaning that their state can be reversibly changed by external stimuli. For example, Patent Document 1 describes a polymeric compound in which at least one end of a skeletal polymer is bound with coumarin or a derivative thereof. The fluidity of this polymeric compound can be changed from a first state to a second state by irradiation with light of a first wavelength, and can be reversibly changed from the second state to the first state by irradiation with light of a second wavelength different from the first wavelength.

[0003] Existing technical documents Patent documents Patent Document 1: International Publication No. 2023 / 120191 Summary of the Invention The technical problem that the invention aims to solve Patent Document 1 describes the use of a polymeric compound, in which at least one end of a skeletal polymer is bound to coumarin or a derivative thereof, as a material for 3D printers. However, no discussion is made regarding the use of the aforementioned polymeric compound to provide cosmetic compositions with reversible light responsiveness.

[0004] One aspect of the present invention aims to provide a cosmetic composition that uses a polymeric compound with at least one end of a backbone polymer bound to a coumarin or a derivative thereof, and has reversible photoresponsiveness.

[0005] Technical solutions to solve technical problems One aspect of the present invention for solving the above problems is a cosmetic composition containing a polymeric compound in which at least one end of a backbone polymer is bound with a coumarin or a derivative thereof. The fluidity of the cosmetic composition can be changed from a first state to a second state by irradiation with light of a first wavelength, and can be reversibly changed from the second state to the first state by irradiation with light of a second wavelength different from the first wavelength.

[0006] The effects of the invention According to one aspect of the present invention, a polymeric compound having coumarin or a derivative thereof attached to at least one end of a backbone polymer can provide a cosmetic composition having reversible light responsiveness. Attached Figure Description

[0007]

【 Figure 1 The graph shows the change in viscoelasticity of the composition of Example 1-1 over time.

[0008]

【 Figure 2The graph shows the change in viscoelasticity of the compositions in Examples 1-2 over time.

[0009]

【 Figure 3 The graph shows the change in viscoelasticity of the compositions in Examples 1-3 over time.

[0010]

【 Figure 4 The graph shows the change in viscoelasticity of the compositions in Examples 1-4 over time.

[0011]

【 Figure 5 The graph shows the change in viscoelasticity of the compositions in Examples 1-5 over time.

[0012]

【 Figure 6 The graph shows the change in viscoelasticity of the compositions of Examples 2-1 and 2-2 over time.

[0013]

【 Figure 7 The graph shows the change in viscoelasticity of the composition in Example 2-2 over time when it is alternately irradiated with light of different wavelengths. Detailed Implementation

[0014] One embodiment of the present invention is a cosmetic composition containing a polymeric compound with at least one end of a skeletal polymer having a coumarin or a derivative thereof attached thereto, and its fluidity being able to change from a first state to a second state by irradiation with light of a first wavelength, and being able to reversibly change from the second state to the first state by irradiation with light of a second wavelength different from the first wavelength.

[0015] The inventors prepared various compositions by combining polymeric compounds with at least one end of a skeletal polymer bonded to coumarin or its derivatives with solvents and other components, and investigated their photoresponsiveness. The results showed that cosmetic compositions containing polymeric compounds with at least one end of a skeletal polymer bonded to coumarin or its derivatives were obtained, and these cosmetic compositions themselves exhibited reversible photoresponsiveness.

[0016] <Definitions, etc.> The term "cosmetic composition" in this specification includes cosmetics, quasi-medical products (quasi-drugs), and personal care products (daily hygiene products). These are sometimes collectively referred to as cosmetics, etc. Furthermore, the "cosmetic composition" also includes a base agent used to prepare the aforementioned cosmetics, etc. That is, the cosmetic composition of this embodiment can be provided as the final product itself or as a raw material used to prepare the final product. Examples of cosmetics, etc., include: skin care products or basic cosmetics such as lotions, emulsions, and serums; color cosmetics such as setting sprays, lipsticks, lip glosses, foundations, blushes, eyeshadows, and nail polish; and hair care cosmetics such as hairspray and hair wax. Furthermore, examples of personal care products (daily hygiene products) include: sunscreens, body lotions, body washes, hair conditioners, and hand creams.

[0017] In this specification, "photoresponsiveness" refers to a property that changes when exposed to light of a specific wavelength, including at least a change in fluidity. Furthermore, photoresponsiveness, in addition to changes in fluidity, sometimes also includes changes in properties such as color when exposed to light of a specific wavelength.

[0018] Furthermore, the term "flowability" in this specification can refer to properties that can be measured as rheological characteristics such as viscosity, elasticity, and viscoelasticity, or properties that can be evaluated through tactile sensory evaluations such as smoothness, softness, and lack of abrasion when touched by a human. When measuring rheological properties, instruments such as rheometers can be used. Changes in rheological properties can be measured as changes in elastic modulus such as storage modulus G' (Pa), loss modulus G'' (Pa), viscosity, shear rate (shear strength), and thixotropic index. In addition, rheological properties can also be changes in properties that can be visually observed by causing the substance to flow, i.e., by changing the forces (including gravity) applied to the composition.

[0019] The change is "reversible" because after the fluidity changes from a first state to a second state, it can change back from the second state to the first state. This change only needs to be a change that repeats at least once between the first and second states, preferably more than twice. Such a reversible change is, for example, sufficient to satisfy the following conditions: after the fluidity changes from the first state to the second state by irradiating light of a first wavelength, it then changes back from the second state to the first state by irradiating light of a second wavelength; or, after the fluidity changes from the second state to the first state by irradiating light of a second wavelength, it then changes back from the first state to the second state by irradiating light of a first wavelength.

[0020] Furthermore, the two distinct states of fluidity, the first and second states, are not particularly limited as long as they are distinguishable. For example, when the first state is a high-flow state with relatively high fluidity and the second state is a low-flow state with relatively low fluidity, the distinction can be made by using an indicator representing fluidity (such as a specified value of measurable rheological properties, a specified sensory evaluation value, etc.) as the boundary. For instance, the first state of fluidity can be liquid and the second state can be solid, or the first state of fluidity can be sol and the second state can be gel.

[0021] <Polymer Compounds> The polymer used in this embodiment is a compound in which coumarin or its derivatives are bonded to at least one end of the backbone polymer constituting the main chain, such as the compound described in International Publication No. 2023 / 120191. When this polymer is irradiated with light of a first wavelength, its fluidity changes to a first state; when irradiated with light of a second wavelength different from the first wavelength, its fluidity changes to a second state. This change in the polymer's fluidity is caused by the polymer's molecular structure itself and is accompanied by changes in the formation and breaking of intermolecular bonds (specifically, covalent bonds). For example, when a cross-linked polymer in an uncrosslinked state is irradiated with light of a first wavelength, the cross-linked polymers bond together to form a cross-linked polymer compound (also simply called a cross-linked compound) in a cross-linked state. When the cross-linked polymer compound is irradiated with light of a second wavelength, the bonds within the cross-linked polymer compound break, forming a cross-linked polymer compound. This formation and breaking of intermolecular bonds is obtained through the formation and breaking of bonds between coumarin or its derivatives bonded to the ends of the backbone polymer.

[0022] In addition, unless otherwise stated in this specification, "polymer compound" includes cross-linked polymer compounds and / or polymer cross-linked products formed by cross-linking cross-linked polymer compounds. The ratio of cross-linked polymer compounds to polymer cross-linked products in a cosmetic composition may vary depending on the light irradiation conditions (e.g., wavelength, intensity, duration of irradiation, etc.).

[0023] There are no particular limitations on the backbone polymer constituting the polymer compound, but it is preferred that the backbone polymer itself (in the state before the introduction of coumarin or its derivatives) has high fluidity at room temperature, preferably in a liquid or sol state.

[0024] Examples of backbone polymers include polysiloxane polymers, polyacrylate polymers, polymethacrylate polymers, polystyrene polymers, polyethylene polymers, polyamide polymers, polyester polymers, and polyurethane polymers. Polysiloxane polymers are preferred. Examples of polysiloxane polymers include polydimethylsiloxane (PDMS), polymethylphenylsiloxane, and polymethylhydrosiloxane, with polydimethylsiloxane (PDMS) being preferred. Furthermore, one or more of the above polymers can be used as the backbone polymer.

[0025] The number average molecular weight of the backbone polymer is preferably 500 to 100,000, more preferably 1,000 to 50,000. Furthermore, the glass transition temperature of the backbone polymer is preferably -150°C to 25°C, more preferably -120°C to 0°C.

[0026] Furthermore, the backbone polymer preferably has a branched structure, and more preferably a structure in which multiple branches (arms) extend from the central core. The portion forming the central core preferably contains carbon atoms or a benzene ring. In particular, when the central core portion is a benzene ring, the structure of the backbone polymer and even the structure of the polymer compound are more stable, thereby ensuring a more reliable change in fluidity between the first and second states, which is therefore preferred. In addition, the number of branches (the number of arms extending from the central core) bonded to the aforementioned central core is preferably 2 to 8 (i.e., the backbone polymer has 2 to 8 branched structures), more preferably 2 to 5 (i.e., the backbone polymer has 2 to 5 branched structures), or 3 to 6 (i.e., the backbone polymer has 3 to 6 branched structures). It is more preferred when the number of branches bonded to the central core in the backbone polymer is 3 (i.e., the backbone polymer has 3 branched structures).

[0027] The backbone polymer portion of the polymer compound involved in this embodiment can take various structures, such as having a hydrocarbon group, a siloxane structure, or the like as a central core, with the polysiloxane structure bonded to the central core. The structure of the backbone polymer portion can be represented by formula (a-1).

[0028]

Chemistry 1

[0029] PS1 can be a chain-like group with one end bonded to Z and the other end bonded to coumarin or a coumarin derivative. The number of repeating siloxane units constituting the polysiloxane structure contained in PS1 can be more than 1 and less than 150. Furthermore, while there are no particular limitations on the repeating siloxane units constituting the polysiloxane structure contained in PS1, the following structures are examples.

[0030]

Chemistry 2

[0031] PS1 may also contain a hydrocarbon chain. The -CH2- in the hydrocarbon chain may be replaced by an oxygen (-O-) group, an ester (-CO-O-) group or -SiR2- (here, R2 is independently hydrogen or an alkyl group having 1 to 3 carbon atoms).

[0032] When Z is a hydrocarbon group with a valence of n1, at least one -CH2- group in the hydrocarbon group can be substituted by an oxygen (-O-) group, an ester (-CO-O-) group, or -SiR2- (here, R2 is independently hydrogen or an alkyl group with 1 to 3 carbon atoms), and at least one hydrogen in the hydrocarbon group can be substituted by -SiR3 or a halogen (here, R3 is independently hydrogen or an alkyl group with 1 to 3 carbon atoms). The number of carbon atoms contained in Z can be 1 to 20. Z is more specifically 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 skeletal polymer portion when Z is a hydrocarbon group with a valence of n1 are given below.

[0033]

Transformation 3

[0034] Furthermore, the backbone polymer is preferably a polydimethylsiloxane with a three-branched structure having a benzene ring as the central core, and more specifically, preferably a polymer of formula (1).

Chemistry 4

[0035] Alternatively, when Z is a siloxane residue with a valence of n1, i.e., when Z is a siloxane residue with n1 bonds, the siloxane residue can be a residue of silicic acid containing one Si, a chain siloxane, a cyclic siloxane, or a cage-like siloxane. Specific examples of Z being a siloxane residue are given below.

[0036]

Transformation 5

Transformation 6

[0037] In this embodiment, the polymer compound has a coumarin or a derivative thereof attached to at least one end of the aforementioned backbone polymer, and has a group derived from the coumarin or its derivative (hereinafter also referred to as the coumarin moiety). It is acceptable for the coumarin or its derivative to be attached to only at least one end of the backbone polymer, but if it is attached to all ends of the backbone polymer, the number of crosslinking points between crosslinking polymer molecules can be increased, which is therefore preferred. Furthermore, since the coumarin or its derivative is attached to the ends rather than as a side chain of the backbone polymer, aggregation of the coumarin moiety and phase separation can be prevented.

[0038] When the backbone polymer has a branched structure, coumarins or their derivatives are bound to at least one end of the backbone polymer branch. Preferably, coumarins or their derivatives are bound to at least 50%, more preferably at least 60%, and even more preferably at least 80% of the backbone polymer branch. Furthermore, it is preferred that coumarins or their derivatives are bound to all ends of the backbone polymer branch.

[0039] Furthermore, the coumarin derivative is not particularly limited as long as it does not impede the reversible change in the flow properties of the polymer compound caused by irradiation with different wavelengths of light as described in this embodiment. For example, the coumarin derivative can be a compound in which substituents are introduced into the coumarin. In this case, one to three hydrogen atoms in a coumarin moiety can be replaced by a substituent. Substituents can be, for example, one or more groups selected from the group consisting of halogen atoms, nitro groups, hydroxyl groups, and alkyl groups (alkyl groups preferably have one to three carbon atoms and can be replaced by halogen atoms, nitro groups, or hydroxyl groups). Therefore, in other words, the polymer compound in this embodiment can be a polymer compound having a substituted or unsubstituted coumarin group (coumaryl) at the end of the skeletal polymer.

[0040] Coumarin derivatives can be more specifically represented by the following formula (a-2).

[0041]

Transformation 7

[0042] The following compounds are examples of coumarin derivatives.

[0043]

Transformation 8

[0044]

Chemistry 9

[0045] Examples of polymeric compounds can be exemplified by compounds represented by formula (2).

[0046]

Chemistry 10

[0047] In formula (2), it is preferred that 50% or less of the R in one branch is hydrogen, more preferably 10% or less, and even more preferably all R are alkyl. Furthermore, when R is alkyl, it is preferably a straight-chain or branched alkyl with 1 to 20 carbon atoms, more preferably a straight-chain or branched alkyl with 1 to 5 carbon atoms, and even more preferably a straight-chain alkyl with 1 to 3 carbon atoms. Additionally, n, m, and p are preferably the same, and it is even more preferable that the three branches branching from the benzene ring as the central core have the same structure. Furthermore, as described above, compounds with coumarin attached to the ends of the branches are sometimes referred to as terminal coumarin-type three-armed star-shaped polydimethylsiloxanes.

[0048] The number-average molecular weight of the cross-linked polymer (the uncross-linked polymer) is preferably 500 to 100,000, more preferably 1,000 to 50,000. When compared under the same irradiation conditions (even if the first and second wavelengths are the same), the viscoelasticity changes may differ depending on the number-average molecular weight of the cross-linked polymer. Therefore, the viscoelasticity of the polymer can be controlled by changing its molecular weight.

[0049] <State changes of polymers caused by light irradiation> The structural changes of polymer compounds caused by irradiation with light of different wavelengths are explained in more detail below. In this explanation, a three-armed star-shaped polydimethylsiloxane (PDMS) with coumarin groups at the ends of each branch chain is used as an example. In formula (3), the upper part represents the uncrosslinked compound in the first state, i.e., the crosslinked polymer compound; the lower part represents the compound in the second state, i.e., the state in which the coumarin portions of the molecules are crosslinked, i.e., the crosslinked polymer compound. In formula (3), the first state is the high-flow state with high fluidity, and the second state is the low-flow state with low fluidity.

[0050]

Chemistry 11

[0051] The light used to irradiate and change the state of the polymer compound, whether it is light of a first wavelength or light of a second wavelength different from the first wavelength, is preferably ultraviolet light. Here, the range of the first wavelength can be 300 nm to 390 nm, preferably 350 nm to 380 nm, and more preferably 360 nm to 370 nm. The range of the second wavelength can be 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 is 365 nm and the second wavelength is 254 nm. As described above, in this embodiment, the first wavelength used to initiate the change from a high flow state to a low flow state is greater than the second wavelength.

[0052] Furthermore, the polymer compound in this embodiment, once irradiated with light, can maintain its flow characteristics after the irradiation has changed, even after the irradiation stops. That is, if irradiation with light of the first wavelength changes it from a first state to a second state, then even if the irradiation with the first wavelength stops, as long as there is no irradiation with light of the second wavelength or other stimuli that cause a change to the second state, the flow characteristics of the second state can be maintained. Conversely, if irradiation with light of the second wavelength changes it from a second state to a first state, then even if the irradiation with light of the second wavelength stops, as long as there is no irradiation with light of the first wavelength or other stimuli that cause a change to the first state, the flow characteristics of the first state can be maintained. Specifically, after irradiation with light of the first wavelength causes cross-linking between molecules, the formed cross-linking can be maintained even after irradiation stops; and after irradiation with light of the second wavelength causes the cross-linking between molecules to break, the broken cross-linking will remain broken even after irradiation stops.

[0053] <Cosmetic Compositions> The cosmetic composition of this embodiment is a composition containing the aforementioned polymeric compound, wherein at least one end of the backbone polymer is bound with coumarin or a derivative thereof, and other ingredients. The photoresponsiveness of the polymeric compound has been described above, and the cosmetic composition of this embodiment reflects this photoresponsiveness. That is, the cosmetic composition itself can change from a first state to a second state by irradiation with light of a first wavelength, and can reversibly change from the second state to the first state by irradiation with light of a second wavelength different from the first wavelength.

[0054] Other ingredients combined with the cosmetic composition are not particularly limited, as long as they are ingredients suitable for cosmetic use. Since cosmetic compositions are typically applied to human skin, the other ingredients are preferably those with good spreadability (flowability that allows for easy application using conventional methods). Furthermore, these other ingredients are preferably those capable of combining with uncrosslinked polymers to maintain the entire cosmetic composition in a liquid or sol state. Further, these other ingredients are preferably solvents capable of dissolving and / or dispersing crosslinked polymers. The solvent can be an aqueous solvent and / or an oil-based solvent. However, since oil-based solvents readily dissolve the aforementioned polymers, it is preferred that the cosmetic composition contains at least an oil-based solvent, allowing the polymers to be uniformly 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 types of other ingredients they contain. For example, when a cosmetic composition contains an oil-based solvent as one of its other ingredients, it can be provided as an oil-based composition. Since oil-based compositions are compositions that are substantially free of or completely free of aqueous components, the other ingredients are primarily oil-based solvents. On the other hand, when a cosmetic composition contains both oil-based and aqueous solvents as other ingredients, it can be provided as an emulsified composition. Emulsified compositions can be oil-in-water or water-in-oil. When a cosmetic composition is an emulsified composition, it is preferable to add ingredients with emulsifying properties, such as surfactants.

[0056] Furthermore, the cosmetic composition can be a homogeneous composition in which a polymeric compound is dissolved and / or dispersed throughout the composition, or a phase-separated composition in which the polymeric compound is visibly identifiable or where the phase containing the polymeric compound undergoes phase separation. Phase-separated compositions can be homogenized by stirring or the like before application. Therefore, when this embodiment is an emulsified composition, the emulsified composition can be either a homogeneous composition or a phase-separated composition.

[0057] In cosmetic compositions, polymeric compounds can be mixed with other ingredients in any proportion, meaning the content of polymeric compounds in the cosmetic composition can be any amount. Relative to the total amount of the cosmetic composition, the content of polymeric compounds with coumarin or its derivatives bound to at least one end of the backbone polymer 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. By keeping the content of polymeric compounds at 0.1% by mass or more, the photoresponsiveness of the cosmetic composition can be more significantly exhibited. For example, when comparing the storage modulus G' (Pa) or loss modulus G'' (Pa) in a high-flow state (first state) and a low-flow state (second state), the difference is more pronounced. Furthermore, by keeping the content of the photoresponsive compound at 80% by mass or less, the ease of use as a cosmetic can be improved.

[0058] When a cosmetic composition contains an oil-based solvent, the oil-based solvent is one commonly used as an ingredient in cosmetic compositions, as long as it does not absorb light and thus hinder the photoresponsiveness of the cosmetic composition; there are no particular limitations. However, when preparing a cosmetic composition into an oil-based homogeneous composition, from the viewpoint of being able to dissolve well in polymers with at least one end of a skeletal polymer bonded to coumarin or its derivative, a low-molecular-weight and non-polar solvent is preferred. Furthermore, the term "low-molecular-weight" in this specification does not necessarily have a general meaning, but varies depending on the type of solvent, and can refer to the molecular weight comparison between solvents of the same type (e.g., between silicone oils, between hydrocarbon oils). The low-molecular-weight solvent is preferably a volatile solvent.

[0059] One or more low-molecular-weight nonpolar solvents, such as silicone oils and hydrocarbon oils, can be used. Volatile silicone oils are preferred. Furthermore, the silicone oil can be a linear or branched polysiloxane, or a cyclic siloxane. Using linear or cyclic polysiloxanes is preferred because they better dissolve the aforementioned polymeric compounds. Additionally, in this specification, a linear polysiloxane refers to a structure in which hydrogen atoms or methyl groups are bonded to the main framework of siloxane bonds (-Si-O-Si-).

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

[0061] Furthermore, the hydrocarbon oil is preferably a saturated aliphatic hydrocarbon. It is also preferably a volatile hydrocarbon. The hydrocarbon oil used as an oily solvent preferably has 5 to 30 carbon atoms, more preferably 10 to 20. The hydrocarbon oil can be a straight-chain hydrocarbon or a branched hydrocarbon. However, straight-chain hydrocarbons are preferred, or even if it is a branched hydrocarbon, the group constituting the branch chain has 1 carbon atom (i.e., methyl). Specific examples of hydrocarbon oils include isododecane, isohexadecane, hydrogenated polyisobutylene, olefin oligomers (α-olefin oligomers), etc. Furthermore, the molecular weight of the hydrocarbon oil is preferably 50 to 500, more preferably 100 to 300.

[0062] The aforementioned low-molecular-weight nonpolar solvents can be used alone or in combination of two or more. For example, they can be used in combination with multiple silicone oils, multiple hydrocarbon oils, or silicone oils and hydrocarbon oils.

[0063] Furthermore, low-molecular-weight nonpolar solvents can be combined with solvents that are not low-molecular-weight nonpolar solvents, or they can be mixed with polar solvents (such as polar oils). Polar oils combined with low-molecular-weight nonpolar solvents can be, for example, polar silicone oils, polar hydrocarbon oils, ester oils, etc. Ester oils can be, for example, monohydric alcohol fatty acid esters or polyhydric alcohol fatty acid esters, specifically, cetyl ethylhexanoate, pentaerythritol tetraethylhexanoate, etc.

[0064] Furthermore, if the oil-based solvent has a structure that is the same as or similar to the backbone polymer structure of the photoresponsive compound, it can improve the solubility of the photoresponsive compound in the oil-based solvent, and is therefore preferred. For example, if the backbone polymer of the photoresponsive compound is polydimethylsiloxane (PDMS), then PDMS is preferably used as the oil-based solvent, or a silicone oil with PDMS as the main backbone is used.

[0065] When the cosmetic composition in this embodiment contains an oily solvent, regardless of the form of the composition (i.e., the form of an oil-based composition, an emulsion-based composition, etc.), the content of a polymeric compound in which coumarin or its derivatives are attached to at least one end of the backbone polymer is 100 parts by mass, preferably 50 parts by mass or more and 200 parts by mass, more preferably 60 parts by mass or more and 150 parts by mass, and even more preferably 75 parts by mass or more and 125 parts by mass.

[0066] Furthermore, the content of low-molecular-weight nonpolar solvents in the oily solvent is preferably 20% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more, relative to the total amount of oily solvent. Additionally, the oily solvent is preferably composed of or substantially composed of low-molecular-weight nonpolar solvents. Furthermore, "substantially composed of specific components" in the oily solvent means containing 98% by mass or more, preferably 99% by mass or more, and more preferably 99.5% by mass or more of a specific component.

[0067] Furthermore, the content of silicone oil in the oily solvent, relative to the total amount of the oily solvent, is preferably 20% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more. In addition, the oily solvent is preferably composed of silicone oil or substantially composed of silicone oil.

[0068] When a cosmetic composition contains an aqueous solvent, the aqueous solvent can be purified water, deionized water, tap water, water-soluble alcohol, etc. Examples of water-soluble alcohols include lower alcohols, polyols, polyol polymers, alkyl alcohol ethers, ether esters, monoalkyl glycerol ethers, sugar alcohols and their derivatives.

[0069] Furthermore, in the cosmetic composition of this embodiment, other components besides oil-based and water-based solvents may be appropriately included in an amount that does not impede the photosensitivity of the cosmetic composition, depending on the form of the cosmetic composition and the type and function of the cosmetic, etc. Examples of other components besides oil-based and water-based solvents include emulsifiers (including surfactants), surface-treated or untreated inorganic powders (including UV scattering agents), resin particles, solid oil-based components, preservatives, thickeners, humectants, film-forming aids, etc.

[0070] When the cosmetic composition is an emulsifying composition, it is preferable to include a surfactant as an emulsifier. In this case, the surfactant used is not particularly limited as long as it is used in cosmetics and other fields, but a nonionic surfactant is preferred. Examples of nonionic surfactants 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 polyglycerol fatty acid esters such as polyglycerol-2 diisostearate and polyglycerol-2 triisostearate. Furthermore, when the backbone polymer of the photoresponsive compound is polydimethylsiloxane (PDMS, dimethyl silicone oil) or its derivatives, and / or the oily solvent is polydimethylsiloxane (PDMS, dimethyl silicone oil) or its derivatives, silicone surfactants are also preferred because they can exhibit particularly high emulsifying properties. One or more surfactants may be used in combination.

[0071] <Specific usage examples> As described above, the cosmetic composition of this embodiment exhibits a change in fluidity upon light irradiation, thus making it suitable for use, for example, as a setting liquid. A setting liquid is a cosmetic product applied or sprayed onto the face after makeup application, forming a thin film on the makeup surface to maintain the makeup in its final state. In this case, the cosmetic composition of this embodiment is contained in a light-proof container in a highly fluid state (uncrosslinked state). When used, the highly fluid cosmetic composition is taken from the container and applied or sprayed to form a film. Then, for example, the applied cosmetic composition is exposed to sunlight outdoors. Here, sunlight typically contains a large amount of components within a preferred first wavelength range (i.e., wavelengths between 300 nm and 390 nm), in other words, it contains a large amount of components that reduce the fluidity of the cosmetic composition. Therefore, by exposing the film to sunlight outdoors, the crosslinking reaction of the polymer compounds contained in the cosmetic composition can be easily promoted, the fluidity of the cosmetic composition decreases, the film solidifies, and it reliably adheres to the makeup surface. Afterward, even when moving from outdoors to indoors, the fluidity of the cosmetic composition remains unchanged even without substantial ultraviolet radiation, thus maintaining the makeup's effectiveness. In addition, when you want to remove makeup, for example by irradiating light within the preferred range of a second wavelength, i.e., wavelengths between 200 nm and 290 nm, the film of the setting liquid can be made to be in a highly fluid state, so that makeup can be easily removed along with the setting liquid.

[0072] In this way, the cosmetic composition of this embodiment not only forms a cosmetic composition film on the skin, but also allows the film to be cured by light irradiation. Therefore, it can effectively prevent the loss of facial moisture and can also be used as a moisturizing cosmetic.

[0073] Furthermore, the light irradiation of the cosmetic composition of this embodiment can be carried out under conditions of 0°C to 100°C, preferably at room temperature (5°C to 35°C), and the light intensity is preferably 0.2 mW / cm². 2 Above 40mW / cm 2 The following is a range of light intensity. This range also covers the intensity of normal outdoor solar ultraviolet radiation.

[0074] Example <Synthesis of Polymers> The following synthesized polymeric compounds with coumarin groups at the ends.

[0075]

Chemistry 12

[0076] Furthermore, as described below, the coumarin moiety was introduced into the branch ends of the terminal hydrosilane-type three-armed star-shaped PDMS.

[0077]

Chemistry 13

[0078] <Experiment I> The above-mentioned polymer compound (PDMS-coumarin) was mixed with an equal mass of the oily solvents shown in Table 1 at 25°C to prepare the compositions of Examples 1-1 to 1-5.

[0079] Table 1 1: KF-96L-1.5CS: Manufactured by Shin-Etsu Chemical Industry Co., Ltd. 2: KF-96A-6CS: Manufactured by Shin-Etsu Chemical Industry Co., Ltd. The viscoelasticity of each composition was measured using a rotational rheometer (Anton Paar, MCR-102). Specifically, a sample was coated to a thickness of 0.1 mm on the surface of the glass lower plate of the rotational rheometer. A parallel plate (12 mm in diameter) was placed and rotated at a frequency of 1 Hz. Starting 120 seconds after the start of rotation, the sample was irradiated from below the lower plate with a wavelength of 365 nm (150 mW / cm²). 2 The energy storage modulus G' (Pa) and loss modulus G'' (Pa) were measured over time after 120 minutes of exposure to ultraviolet light. The measurement results are shown in the graph below. Figures 1-5 As shown.

[0080] In addition, the changes in viscoelasticity of each composition were evaluated as follows. The evaluation results are shown in Table 1.

[0081] ○: The viscoelastic changes caused by light irradiation can be confirmed by both measurement data and visual observation.

[0082] △: The viscoelastic changes caused by light irradiation cannot be detected by the naked eye, but can be confirmed by measurement data.

[0083] ×: The viscoelastic changes caused by light irradiation cannot be confirmed by either measurement data or visual observation.

[0084] like Figures 1 to 5 As shown, it can be seen that a composition made by mixing PDMS-coumarin with an oily solvent such as hydrocarbon oil, ester oil or silicone oil can be altered by light irradiation.

[0085] <Experiment 2> Cosmetic compositions were prepared using the PDMS-coumarin described above, according to the formulations shown in Table 2. The compositions of Examples 2-1 and 2-2 were both prepared as setting solutions for use in the final stage of makeup application, with Example 2-1 being an example.

[0086] Table 2 3: KF-7312K: Manufactured by Shin-Etsu Chemical Industry Co., Ltd. The viscoelasticity of the compositions of Examples 2-1 and 2-2 was measured using a rotational rheometer (Anton Paar, MCR-102). Specifically, assuming the volatile components were dry after coating, each composition, after being dried under reduced pressure overnight at 40°C, was coated with a sample to a thickness of 0.1 mm on the glass lower plate surface of the aforementioned rotational rheometer. A parallel plate (12 mm in diameter) was placed and rotated at a frequency of 1 Hz. Starting 120 seconds after the start of rotation, the samples were irradiated from below the lower plate with a wavelength of 365 nm (150 mW / cm²).2 The energy storage modulus G' (Pa) and loss modulus G'' (Pa) were measured over time after 120 minutes of exposure to ultraviolet light. The measurement results are shown in the graph below. Figure 6 As shown.

[0087] like Figure 6 As shown, the viscoelasticity of the composition in Example 2-1 containing PDMS-coumarin changed significantly due to light irradiation. On the other hand, no change in viscoelasticity due to light irradiation was observed in the composition of Example 2-2, which does not contain PDMS-coumarin. Furthermore, comparing Example 2-1 and Example 2-2, it can be seen that the viscoelasticity (i.e., storage modulus G' and loss modulus G'') of the compositions was approximately the same initially (before light irradiation), but as... Figure 6 As shown, significant differences were observed after light exposure.

[0088] Furthermore, for the composition of Example 2-1, alternating irradiation at a wavelength of 365 nm (150 mW / cm²) 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 using ultraviolet light. The same rotary rheometer as described above was used for the measurements, and the instrument operating conditions were identical. The ultraviolet irradiation procedure was as follows: starting 120 seconds after the start of rotation, the instrument was irradiated from below the lower plate with a wavelength of 365 nm (150 mW / cm²). 2 After 300 seconds of exposure to ultraviolet light, the exposure stops. After 300 seconds of no exposure, irradiation begins again with a wavelength of 254 nm (17 mW / cm). 2 The device was exposed to ultraviolet light for 300 seconds, then stopped. After 300 seconds without exposure, this cycle was repeated six times. The measurement results are shown in the graph below. Figure 7 As shown.

[0089] like Figure 7 As shown, the composition of Example 2-1 containing PDMS-coumarin exhibits a reversible state change: viscoelasticity increases upon irradiation with light of a specific wavelength, while viscoelasticity decreases upon irradiation with light of other wavelengths different from the aforementioned specific wavelength. This demonstrates that PDMS-coumarin exhibits reversible photoresponsiveness even in the form of a composition prepared by mixing with a solvent.

[0090] The present invention has been described above based on specific embodiments and examples. However, these embodiments and examples are given only as examples, and the present invention is not limited to the above embodiments and examples. Within the scope of the present invention, various changes, modifications, substitutions, deletions, additions, and combinations can be made.

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

Claims

1. A cosmetic composition comprising a polymeric compound having a coumarin or a derivative thereof bound to at least one end of a backbone polymer. The fluidity of the cosmetic composition can be reversibly changed as follows: from a first state to a second state by irradiating with light of a first wavelength, and from the second state to the first state by irradiating with light of a second wavelength different from the first wavelength.

2. The cosmetic composition according to claim 1 is an oil-based composition that further contains an oily solvent.

3. The cosmetic composition according to claim 1 is an emulsified 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 nonpolar solvent.

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

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

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

10. The cosmetic composition according to claim 1 or 2, wherein the polymeric compound is formed by combining a skeletal polymeric moiety represented by formula (a-1) with a moiety comprising a non-substituted coumarin group or a coumarin derivative represented by formula (a-3), In equation (a-1), Z is a hydrocarbon group with 1 to 20 carbon atoms and a valence of n1, or a siloxane structure with a valence of n1. PS1 is an independent polysiloxane structure and may also contain a hydrocarbon chain, in which at least one -CH2- group may be replaced by an oxygen (-O-) group, an ester (-CO-О-) group, or -SiR2-, and R2 is independently hydrogen or an alkyl group having 1 to 3 carbon atoms. n1 is between 1 and 6. # indicates the relationship with equation (a-3) The location of the union, In equation (a-3), This indicates the position where the # symbol is combined with equation (a-1). L is a single bond or a hydrocarbon chain with 1 to 20 carbon atoms. When L is the hydrocarbon chain, at least one -CH2- group in the hydrocarbon chain can be replaced by an oxygen (-O-) group or an ester (-CO-O-) group, and at least one hydrogen atom in the hydrocarbon chain can be replaced by -SiR3 or a halogen, where each R3 is independently a hydrogen atom or an alkyl group with 1 to 3 carbon atoms. R a Each of the following groups is independently a halogen atom, a nitro group, a hydroxyl group, a phenyl group, a benzyloxy group, a straight-chain alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, a straight-chain 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, wherein the alkyl or alkoxy group may be substituted with a halogen atom, a nitro group, or a hydroxyl group. R a When methylene (-CH2-) is included, at least one of them may be substituted by dimethylsilyl (-Si(CH3)2-), oxygen (-O-) or carbonyl (-C=O-).

11. The cosmetic composition according to claim 10, wherein Z in formula (a-1) is an aromatic hydrocarbon group with 20 or fewer carbon atoms and a valence of n1. At least one -CH2- in the hydrocarbon group may be replaced by an oxygen (-O-) group, an ester (-CO-О-) group or -SiR2-, and at least one hydrogen in the hydrocarbon group may be replaced by -SiR3 or a halogen, wherein R2 and R3 are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms.

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