Polymer compound

Abstract

The present invention provides a novel photoresponsive compound and a composition containing the same. The compound has a partial structure in which styrylpyrene or a derivative thereof is bonded to at least one end of a backbone polymer. A composition according to the present invention contains the aforementioned compound and an oily solvent.

Description

polymer compound

[0001] The present invention relates to a polymer compound.

[0002] Materials whose state can be reversibly changed in response to an external stimulus are known. For example, Patent Document 1 describes a photoresponsive polymer whose bonds are cleaved by a light stimulus, allowing it to reversibly change from a solid state to a liquid state. However, in the case of the compound described in Patent Document 1, the cleaved bonds are reformed when the application of the light stimulus is stopped. Therefore, the compound cannot be used in an environment without the light stimulus in the state after the change caused by the light stimulus. Patent Document 2 discloses a reversibly changeable material that changes state when a light stimulus is applied, maintains the changed state even after the application of the light stimulus is stopped, and can recover to its original state when a different stimulus is applied. Specifically, this material is a polymer compound characterized by a partial structure in which coumarin or a derivative thereof is bonded to at least one end of the backbone polymer, and its fluidity is reduced by irradiation with light having a wavelength of approximately 365 nm, and the fluidity of the reduced-fluid compound is increased by irradiation with light having a wavelength of approximately 254 nm. Although such materials can be used in a variety of applications, for example, when natural light is used as the light to be irradiated, since natural light contains relatively little ultraviolet light, in order to improve the responsiveness to light stimuli, a material that is highly responsive to light with wavelengths in the visible light region, which is relatively abundant in natural light, is desired. Furthermore, because ultraviolet light is harmful to the human body and from the viewpoint of the cost of irradiation equipment, materials that are responsive to light with wavelengths longer than ultraviolet light are preferred.

[0003] JP 2017-149793 A International Patent Publication No. 2023 / 120191

[0004] According to the present invention, the following inventions are provided: [1] A compound characterized by having a partial structure in which styrylpyrene or a derivative thereof is bonded to at least one end of a main chain or a side chain of a backbone polymer containing a polysiloxane structure. [2] The compound according to [1], which is reversibly changeable 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. [3] The compound according to [2], in which (i) by irradiating the compound with light of the first wavelength, an unsaturated double bond contained in a partial structure in which styrylpyrene or a derivative thereof is bonded is cleaved, forming a structure containing a cyclized adduct between the partial structures in which two styrylpyrenes or derivatives thereof are bonded, thereby transitioning to the second state; or (ii) by irradiating the compound with light of the second wavelength, the structure containing the cyclized adduct is cleaved, separating into two partial structures in which styrylpyrene or a derivative thereof is bonded, thereby transitioning to the first state. [4] The compound according to [2] or [3], wherein the fluidity in the first state is higher than the fluidity in the second state. [5] The partial structure to which the styrylpyrene or a derivative thereof is bonded is represented by the formula (a): (Wherein, L is a hydrocarbon chain, and —CH ２ - is an oxy (-O-) group, an ester (-CO-O-) group, or -SiR ２ -, and the hydrogens of the hydrocarbon chain may be replaced by -SiR ３ or halogen (wherein R is independently hydrogen or an alkyl group having 1 to 3 carbon atoms), the number of carbon atoms contained in L is 1 to 20, and R ａ２ are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a hydroxyl group, na2 is 0 to 4, and R ａ３ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms; R ａ４are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a hydroxyl group, na4 is 0 to 10, and * indicates a bonding position to a backbone polymer. [6] The compound according to any one of [1] to [4], wherein the partial structure to which the styrylpyrene or a derivative thereof is bonded is represented by formula (a-1) or (a-2): (In the formula, R ａ１ [7] The compound according to any one of [1] to [5], wherein the backbone polymer is represented by formula (b-1): Z-(PS1) ｎ１ -# (b-1) (wherein Z is a hydrocarbon group having a valence of n1, and each PS1 is independently a polysiloxane structure, and -SiR ｂ ２ O- (where R ｂ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms) is -(CR ｂ ' ２ ) ｎｂ’ - (where R ｂ’ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and nb' represents a group having 1 to 5 carbon atoms), n1 represents a group having 1 to 10, and # represents a bonding position to an end group of a polysiloxane structure or to a partial structure to which the styrylpyrene or a derivative thereof is bonded. [8] The polymer compound according to any one of [1] to [6], wherein the backbone polymer is represented by formula (b-2): PS2-# ｎ２ (b-2) (wherein, PS2 is a polysiloxane structure having a valence of n2, and —SiR ｂ ２ O- (where R ｂ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms) is -(CR ｂ ' ２ ) ｎｂ’ - (where R ｂ’each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and nb' represents a group having 1 to 5 carbon atoms), n2 represents a group having 1 to 10 carbon atoms, and # represents a bonding position to an end group of the polysiloxane structure or to a partial structure to which the styrylpyrene or a derivative thereof is bonded. [9] The polymer compound according to any one of [1] to [7], wherein the backbone polymer containing the polysiloxane structure is represented by formula (b-1-1) or (b-1-2): (In the formula, R ｂ１ are each independently a hydrogen atom, an alkyl group, a halogen-substituted alkyl group, an alkenyl group, a halogen-substituted alkenyl group, an aryl group, or a halogen-substituted aryl group; nb1 is each independently 1 to 150; R ｂ’ each independently represents hydrogen or an alkyl group having 1 to 3 carbon atoms, nb' represents 1 to 5, and # represents a bonding position to the partial structure to which the styrylpyrene or a derivative thereof is bonded.

[10] The polymer compound according to any one of [1] to [9], wherein the backbone polymer has a glass transition temperature of −130° C. or higher and 0° C. or lower.

[11] The polymer compound according to any one of [1] to

[10] , wherein the backbone polymer has a number average molecular weight of 1,000 or higher and 100,000 or lower.

[12] The polymer compound according to any one of [1] to

[11] , wherein the first wavelength is 400 to 500 nm or higher and the second wavelength is 380 nm or lower.

[13] A composition comprising the compound according to any one of [1] to

[12] and an oily solvent.

[14] The composition according to

[13] , wherein the oily solvent comprises a silicone oil, a hydrocarbon oil, or a mixture thereof.

[0005] According to the present invention, it is possible to provide a reversibly changeable material whose state, for example, fluidity, changes upon application of a light stimulus, can be maintained even after the application of the light stimulus is stopped, and can be reversibly restored to its original state upon application of light stimulus with a different wavelength. Moreover, the light used for the state change and restoration in the present invention is light that is relatively abundant in natural light.

[0006] 1 is a graph showing the results of viscoelasticity evaluation in Example 2. FIG. 2 is a graph showing the results of viscoelasticity evaluation in Example 4. FIG. 3 is a graph showing the results of viscoelasticity evaluation in Example 5. FIG. 4 is a graph showing the results of viscoelasticity evaluation in Example 6. Specific Description of the Invention

[0007] <Change in Flow Properties> One aspect of the present invention is a compound characterized by having a partial structure in which styrylpyrene or a derivative thereof is bonded to at least one end of a main chain or a side chain of a backbone polymer containing a polysiloxane structure. The polymer compound has photoresponsiveness, in which the flow properties can be reversibly changed between a first state and a second state in response to a light stimulus. More specifically, the flow properties of the polymer compound according to this aspect can be changed from the first state to the second state by irradiation with light of a first wavelength, and can be at least partially restored from the second state to the first state by irradiation with light of a second wavelength different from the first wavelength. Note that in this aspect, for convenience, a state in which the flow properties are relatively high will be referred to as the first state, and a state in which the flow properties are relatively low will be referred to as the second state.

[0008] As used herein, a change in flow properties (or a change in fluidity) refers to a change in a physical property related to the viscosity, elasticity, or viscoelasticity of a compound, and more specifically, may be a change in one or more physical properties such as elastic modulus such as storage modulus G' (Pa) and loss modulus G" (Pa), viscosity, shear rate (shear strength), thixotropy index, and other rheological properties. Furthermore, a change in flow properties may be a change from one of the three states of a substance to another. Thus, for example, it may be a change between a solid or gel-like state and a liquid or sol-like state. As used herein, a change between a first state and a second state is not simply due to a change in crystallinity or the like, but is due to a change in the molecular structure itself, and includes changes accompanied by the formation or cleavage of covalent bonds.

[0009] The change may be, for example, such that the difference in storage modulus G' between the first state with high fluidity and the second state with low fluidity is preferably 300 Pa or more and 10,000 Pa or less. Also, the difference in loss modulus G" between the first state with high fluidity and the second state with low fluidity may be 300 Pa or more and 100,000 Pa or less.

[0010] The light irradiated to change the state of the polymer compound is preferably visible light, both for the light of the first wavelength and for the light of the second wavelength different from the first wavelength. Here, the first wavelength range is preferably 400 to 500 nm, more preferably 410 to 480 nm, and even more preferably 420 to 460 nm. The second wavelength range is preferably 380 nm or less, more preferably 300 to 360 nm, and even more preferably 320 to 340 nm. Furthermore, it is particularly preferred that the first wavelength is 436 nm and the second wavelength is 330 nm.

[0011] In this embodiment, it is preferable that irradiation with light of the first wavelength causes formation of a structure containing a cyclized adduct between partial structures in which styrylpyrene or a derivative thereof contained in the polymer compound is bonded, thereby further polymerizing the polymer compound, thereby reducing the fluidity of the polymer compound, and irradiation with light of the second wavelength causes cleavage of the partial structure containing the cyclized adduct.

[0012] Furthermore, once the polymer compound according to this embodiment is irradiated with light, the state after the change due to the irradiation, such as flow characteristics, can be maintained even after the light irradiation is stopped. That is, if a compound in a first state is changed from the first state to a second state by irradiating it with light of a first wavelength, the second state will be maintained even after the irradiation of light of the first wavelength is stopped, unless a special stimulus, such as irradiation with light of a second wavelength, is applied. Also, if a compound in a second state is changed from the second state to the first state by irradiating it with light of a second wavelength, the second state will be maintained even after the irradiation of light of the second wavelength is stopped, unless a special stimulus, such as irradiation with light of the first wavelength, is applied. Considering such a state change in terms of a structural change of the compound, the polymer compound according to this embodiment forms a structure containing a cyclized adduct between partial structures contained in the polymer compound by irradiating it with light of the first wavelength, and the formed structure is maintained even after the irradiation is stopped. Then, by irradiating the compound that formed the structure with light of the second wavelength, the structure containing the cyclized adduct is cleaved, and the cleaved structure remains cleaved even after the irradiation is stopped. Therefore, for example, by alternately irradiating the polymer compound of this embodiment with light of the first wavelength and light of the second wavelength, the polymer compound can repeatedly change reversibly between the first state and the second state.

[0013] The change in flow characteristics due to light irradiation may occur in a system in which a polymer compound is mixed with another component such as a dispersion solvent, or in a system in which no other component is mixed with the polymer compound. In this embodiment, the flow characteristics of the polymer compound can be reversibly changed by irradiating the polymer compound with light, even in a system that does not contain a solvent, so that the polymer compound can be used for various purposes without having to consider evaporation of the solvent during use.

[0014] <Structure of Polymer Compound> The polymer compound according to this embodiment has a partial structure in which styrylpyrene or a derivative thereof is bonded to at least one end of the main chain or side chain of a skeleton polymer containing a polysiloxane structure. The skeleton polymer containing a polysiloxane structure is not particularly limited as long as it can form a polymer compound whose flow properties can be reversibly changed between a first state and a second state upon irradiation with light of different wavelengths as described above, when it has a partial structure in which styrylpyrene or a derivative thereof is bonded. However, it is preferable that the skeleton polymer has high flowability at room temperature and is preferably in a liquid or sol state.

[0015] The backbone polymer can have a variety of structures, for example, a structure in which a hydrocarbon group or the like is used as a central core to which a polysiloxane structure is bonded. Such a structure can be represented by formula (b-1): Z-(PS1) ｎ１ -# (b-1) (wherein Z is a hydrocarbon group having a valence of n1, each PS1 is independently a polysiloxane structure, n1 is 1 to 6, and # represents the bonding position to the terminal group of the polysiloxane structure or the partial structure to which the styrylpyrene or a derivative thereof is bonded).

[0016] Z is, for example, an aromatic hydrocarbon group or an aliphatic hydrocarbon group, preferably an aromatic hydrocarbon, and particularly preferably a benzene ring. It is particularly preferable that Z, which serves as the central core, is a benzene ring, since this stabilizes the structure of the backbone polymer, and ultimately the structure of the polymer compound according to this embodiment, thereby enabling a more reliable change in flow characteristics 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 1 to 10, more preferably 2 to 8, and even more preferably 2 to 5 or less, or 3 to 6. It is even more preferable that the number of branched chains attached to the central core in the backbone polymer is 3 (i.e., the backbone polymer has a tri-branched structure).

[0017] In formula (b-1), PS1 is a polysiloxane structure. The polysiloxane structure preferably has the structure: -(SiR ０２ -O) ｎ０ - R contained in the structure ０ are each independently preferably a hydrogen atom, an alkyl group, a halogen-substituted alkyl group, an alkenyl group, a halogen-substituted alkenyl group, an aryl group, or a halogen-substituted aryl group. Furthermore, n0 is preferably about 3 to 160. ０ is, for example, hydrogen, a methyl group, an ethyl group, a vinyl group, or a phenyl group.

[0018] Examples of repeating units constituting the polysiloxane structure include the following.

[0019] Typically, the backbone polymer preferably contains polydimethylsiloxane (PDMS). Note that, as the backbone polymer, one or a combination of two or more types of polymers having different structures may be used.

[0020] 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 following formula: [wherein nb1 is 1 or more and 150 or less, nb' is 1 or more and 5 or less, and all three branched chains have the same structure]. Note that a PDMS in which the ends of the branched chains are formed with hydrosilanes as described above is sometimes called a hydrosilane-terminated three-armed star polydimethylsiloxane.

[0021] The backbone polymer may not have a central core. Such a structure can be represented by formula (b-2): PS2-# ｎ２ (b-2) (wherein, PS2 is a polysiloxane structure having a valence of n2, n2 is 1 to 10, and # indicates the bonding position to the terminal group of the polysiloxane structure or the partial structure to which the styrylpyrene or its derivative is bonded.)

[0022] In such a structure, n2 terminal hydrogen atoms or terminal alkyl groups at any position of the polysiloxane serve as bonding sites to the partial structure to which styrylpyrene or a derivative thereof is bonded. ０ -(SiR ０ ２ -O) ｎ０ -R ０ (R ０ is defined as above), n2 R ０ The above formula shows that the polysiloxane is linear, but the polysiloxane itself may have a branched structure. Such a backbone polymer containing a polysiloxane structure is represented by formula (b-1-1) or (b-1-2): (In the formula, R ｂ１ are each independently a hydrogen atom, an alkyl group, a halogen-substituted alkyl group, an alkenyl group, a halogen-substituted alkenyl group, an aryl group, or a halogen-substituted aryl group; nb1 is each independently 1 to 150; R ｂ’ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, nb' is 1 to 5, and # indicates the bonding position to the partial structure to which the styrylpyrene or a derivative thereof is bonded.

[0023] The number average molecular weight of the backbone polymer may be preferably 150 or more and 100,000 or less, more preferably 1,000 or more and 50,000 or less. The backbone polymer also preferably has a glass transition temperature of −150° C. or more and 25° C. or less, more preferably −120° C. or more and 0° C. or less.

[0024] The polymer compound according to this embodiment has a partial structure in which styrylpyrene or a derivative thereof is bonded to at least one end of the above-described backbone polymer, and has a group derived from styrylpyrene or a derivative thereof (styrylpyrene moiety). In the present invention, the partial structure in which styrylpyrene or a derivative thereof is bonded is based on a structure in which a styryl group is bonded to a pyrene backbone, and can contain any substituent as long as the effects of the present invention are not impaired. Such a partial structure in which styrylpyrene or a derivative thereof is bonded is, for example, represented by formula (a). Here, L is a hydrocarbon chain, which may be linear or branched, or may contain a cyclic structure, but is preferably linear. ２ - is an oxy (-O-) group, an ester (-CO-O-) group, or -SiR ２ In particular, it is preferable that L contains an ester (—CO—O—) group, and that this ester group is directly bonded to the benzene nucleus in formula (a). In addition, hydrogen atoms in the hydrocarbon chain may be replaced by —SiR ３ Each R is independently hydrogen or an alkyl group having 1 to 3 carbon atoms. The number of carbon atoms contained in L is 1 to 20, preferably 2 to 10. ａ２ are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a hydroxyl group, and preferably an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 8 carbon atoms. na2 is 0 to 4, and preferably 0 to 2. When na2 is 0, this structure is R ａ２ means that it does not contain R ａ３ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, and are preferably hydrogen or a methyl group. ａ３ The unsaturated double bond to which R is bonded may have a cis or trans geometric isomer, but either is acceptable in the present invention. ａ４are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a hydroxyl group, and preferably an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 8 carbon atoms. na4 is 0 to 10, and preferably 0 to 4. When na4 is 0, this structure is R ａ４ In addition, * indicates the bonding position to the backbone polymer.

[0025] The partial structure to which such styrylpyrene or a derivative thereof is bonded is preferably represented by formula (a-1) or (a-2). In the formula, R ａ１ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, preferably hydrogen; and na1 is 2 to 8, preferably 2 to 4.

[0026] In this embodiment, irradiation with light of a first wavelength cleaves an aliphatic unsaturated bond contained in a partial structure to which one styrylpyrene or a derivative thereof is bonded, forming a structure containing a cyclized adduct with an aliphatic unsaturated bond contained in the structure of the styrylpyrene or derivative thereof in another partial structure, thereby changing from a first state to a second state and changing the flow characteristics. Irradiating the compound in the second state with light of the second wavelength cleaves the structure containing the cyclized adduct, changing from the second state to the first state and restoring the flow characteristics. While styrylpyrene or a derivative thereof may be bonded to at least one end of the backbone polymer, bonding to multiple ends of the backbone polymer is preferable because it increases the number of bonding points between the polymer compounds and enables further polymerization. Furthermore, bonding styrylpyrene or a derivative thereof to the end of the backbone polymer rather than as a side chain can prevent the styrylpyrene moieties from aggregating and causing phase separation.

[0027] In the polymer compound according to this embodiment, the partial structure to which styrylpyrene or a derivative thereof is bonded is bonded to at least one end of the branched chain of the backbone polymer. The partial structure to which styrylpyrene or a derivative thereof is bonded 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 the partial structure to which styrylpyrene or a derivative thereof is bonded is bonded to all of the ends of the branched chains of the backbone polymer.

[0028] The styrylpyrene derivative is not particularly limited as long as it does not prevent the reversible change in flow properties of the polymer compound upon irradiation with light of different wavelengths as described above in this embodiment, and may be a styrylpyrene into which a substituent has been introduced, etc. In other words, the polymer compound according to this embodiment may be a polymer compound having a substituted or unsubstituted styrylpyrene group (styrylpyrenyl group) at the end of a backbone polymer.

[0029] The polymer compound according to this embodiment having a partial structure in which styrylpyrene or a derivative thereof is bonded to the terminal thereof includes, for example, the polymer compound of the following formula (I): [R ｂ１ each independently represents hydrogen, an alkyl group, a halogen-substituted alkyl group, an alkenyl group, a halogen-substituted alkenyl group, an aryl group, or a halogen-substituted aryl group; L ｂ is an oxy (—O—) group or an ester (—CO—O—) group, nb1 is independently an integer of 1 to 150, and nb2 is independently an integer of 2 to 8. In the above formula, R ｂ１ may be hydrogen atoms, and R ｂ１ All of R may be hydrogen. ｂ１ 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 alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. ｂ１ is preferably methyl. ｂ１When nb1 is an alkenyl group, it may be a vinyl group, and when nb1 is an aryl group, it may be a phenyl group. It is preferable that each nb1 is the same, and it is even more preferable that the three branched chains branching from the central benzene ring have the same structure. As described above, a compound in which styrenepyrene is bonded to the end of a branched chain is sometimes called a styrenepyrene-terminated three-armed star polydimethylsiloxane.

[0030] <Change in polymer compound structure due to light stimulation> Next, the change in polymer compound structure due to irradiation with light of different wavelengths will be described in more detail. The following formula illustrates the change in structure of a three-arm star-shaped polydimethylsiloxane (PDMS) having a styrylpyrene group at the end of each branched chain. The upper row shows a first state in which partial structures in which styrylpyrene is bonded between molecular chains are not bonded, and the lower row shows a second state in which partial structures in which styrylpyrene is bonded between molecular chains to form a cycloadduct. In this embodiment, the first state is a high-fluidity state with high fluidity, and the second state is a low-fluidity state with low fluidity.

[0031] In the above formula, nb1 is an integer of 1 to 150, and the three branched chains may have the same structure. As shown in the above formula, irradiation with light of a first wavelength can change the first state, which has high fluidity, to the second state, and irradiation with light of a second wavelength can change the second state, which has low fluidity, to the first state. Both the bonding reaction from the first state to the second state and the bond cleavage reaction from the second state to the first state can be carried out under conditions conventional in the art, for example, by light irradiation using a spectral light source. Here, a chemical agent may be used to promote the reaction. Furthermore, in the second state, each carbon atom of the cyclobutane ring at the bond between the two molecules becomes an asymmetric carbon, which can result in multiple isomeric structures, but any structure is acceptable in the present invention.

[0032] In addition, when polymer compounds have different number-average molecular weights, even when irradiated with light of the same wavelength and the same amount of energy, the changes in their state, such as their flow properties, may not be the same. Therefore, it is possible to control the fluctuations in the properties of the compound by changing the molecular weight.

[0033] The present embodiment also relates to a method for using a polymer compound, and the method may include irradiating a polymer compound having a partial structure in which styrylpyrene or a derivative thereof is bonded to at least one end of a backbone polymer with light of a first wavelength to reversibly change the flow characteristics of the polymer compound from a first state to a second state; stopping the irradiation of light of the first wavelength to maintain the second state; and irradiating light of a second wavelength different from the first wavelength to reversibly change the flow characteristics of the polymer compound from the second state to the first state.

[0034] <Composition> The composition according to the present invention comprises the above-described polymer compound and an oily solvent. The oily solvent is not particularly limited, except for those that interfere with the photoresponsiveness of the composition by, for example, absorbing irradiated light.

[0035] Preferably, the oil-based solvent comprises a silicone oil, a hydrocarbon oil, or a mixture thereof. The silicone oil is preferably a volatile silicone oil. The silicone oil may be a linear or branched polysiloxane, or a cyclic siloxane, but linear polysiloxanes or cyclic siloxanes tend to have high solubility for the polymer compounds described above, and are therefore preferred. In this specification, linear polysiloxane refers to a structure in which a main skeleton has a siloxane bond (-Si-O-Si-) and a hydrogen atom or a methyl group is bonded to a silicon atom.

[0036] Specific examples of silicone oils include polydimethylsiloxane (PDMS, dimethicone), polymethylhydrosiloxane (PMHS), cyclomethicone, diphenyldimethicone, phenyltrimethicone, diphenylsiloxyphenyltrimethicone, etc. Among these, phenyl-modified silicone oils such as diphenylsiloxyphenyltrimethicone are preferred. In addition, when the oily solvent is silicone oil, the kinematic viscosity (mm ２The 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.

[0037] The hydrocarbon oil is preferably a saturated aliphatic hydrocarbon. Also, a volatile hydrocarbon is preferable. The hydrocarbon oil used as an oil-based solvent preferably has 5 to 30 carbon atoms, more preferably 10 to 20 carbon atoms. The hydrocarbon oil may be a straight-chain hydrocarbon or a branched hydrocarbon. However, a straight-chain hydrocarbon is preferable, and in the case of a branched hydrocarbon, the group constituting the branched chain bonded to the main chain preferably has 1 carbon atom (a methyl group). Specific examples of hydrocarbon oils include isododecane, isohexadecane, hydrogenated polyisobutene, and olefin oligomer (α-olefin oligomer). The molecular weight of the hydrocarbon oil is preferably 50 to 500, more preferably 100 to 300.

[0038] The oily 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.

[0039] Furthermore, silicone oil or hydrocarbon oil may be combined with other solvents as long as the effect of the present invention is not impaired.Solvents that can be combined with silicone oil or hydrocarbon oil may be, for example, ester oil, ether oil, higher fatty acid, higher alcohol, fats and oils, wax, etc.Ester oil may be, for example, monohydric alcohol fatty acid ester or polyhydric alcohol fatty acid ester, specifically, cetyl ethylhexanoate, pentaerythrityl tetraethylhexanoate, etc.In this case, it is preferable that the content of silicone oil or hydrocarbon oil is 50% or more based on the total mass of the solvent.

[0040] The oily solvent preferably has the same or similar structure as the backbone polymer of the photoresponsive compound, since this tends to increase 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.

[0041] The composition according to the present invention can be used as a cosmetic, an adhesive, a DDS material, an electronic material, etc. When the composition according to the present invention is used as a cosmetic, it can be made into a nail polish, a makeup fixer, a sunscreen, a makeup base, a foundation, etc.

[0042] <Uses, etc.> According to this embodiment, the state of a polymer compound, such as its flow properties, can be changed, for example, between a solid and a liquid, or between a gel and a sol, by light stimulation without relying on heating or the like. Therefore, this embodiment can be suitably used in environments where heating is undesirable. Furthermore, in this embodiment, by irradiating only a partial region of the entire volume of a prepared polymer compound with ultraviolet light of a predetermined wavelength, it is possible to change the properties, such as the flow properties, of only that partial region.

[0043] Furthermore, in the polymer compound of this embodiment, once the flow characteristics have changed, the changed flow characteristics can be maintained even in an environment without light stimulation, even without continuous application of light stimulation, in other words, without continuous light irradiation. Therefore, since the changed state can be maintained even in an environment where light irradiation cannot be continued, the polymer compound can be suitably used, for example, as a material for 3D printers.

[0044] <Synthesis of Polymer Compound> A polymer compound having a styrylpyrene group at its terminal was synthesized as follows.

[0045] (Example 1) A solution of trifunctional silanol (I3) (300 mg), N-cyclohexyl-N'-phenylurea (654 mg) in tetrahydrofuran (THF) (18 mL), a solution of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (208.8 mg) in THF (9 mL), and a solution of hexamethylcyclotrisiloxane (D3) (30.0 g) in THF (36 mL) were dried overnight over 4A molecular sieves. These were mixed at 25°C and stirred for 50 minutes. After stirring, a solution of benzoic acid (3.66 g) in THF (9 mL) was added and stirred for 4 hours. The reaction mixture was distilled to remove volatile components under reduced pressure, and the resulting oily crude product was washed with acetone. The volatile components were then distilled off under reduced pressure. The resulting oily crude product was then dissolved in THF (50 mL). Pyridine (14.5 mL) and chlorodimethylsilane (6.54 mL) were added in that order, and the mixture was stirred for 15.5 hours. The reaction mixture was distilled to remove volatile components under reduced pressure. Excess water / hexane was then poured into the mixture. The hexane layer was washed with water, dried over sodium sulfate, and concentrated. The resulting oily crude product was washed with acetone, and chloroform was added to form a homogeneous solution. The volatile components were then distilled off under reduced pressure to obtain a colorless, oily hydrosilane-terminated three-arm star polydimethylsiloxane (hydrosilane-terminated three-arm star PDMS). The yield was 19.8 g. GPC analysis revealed that the number average molecular weight Mn (RI) of the resulting compound was 16,100 (D = 1.13).

[0046] Furthermore, a styrylpyrene moiety was introduced into the end of the branched chain of the hydrosilane-terminated three-arm star-shaped PDMS as follows.

[0047] The above hydrosilane-terminated three-arm star PDMS (800 mg), 1-(5-hexenyloxystyryl)pyrene (150 mg), Ir catalyst (100 μL), and dichloromethane (DCM) (2 mL) were mixed and stirred at room temperature for 1.5 hours. The reaction mixture was concentrated and washed with methanol and acetone, and the volatile components were distilled off under reduced pressure to obtain 640 mg of oily styrylpyrene-terminated three-arm star PDMS represented by the above formula. GPC measurement revealed that the number-average molecular weight Mn(RI) of the resulting compound was 18,100 (D=1.23). The Ir catalyst was chloro(1,5-cyclooctadiene)iridium(I) (dimer) ([IrCl(cod)] ２ ) (25.0 mg) was dissolved in 1,5-cyclooctadiene (91.0 μL) and dichloromethane (1 mL).

[0048] Example 2 Using the same synthesis method as in Example 1, but adjusting the reaction conditions, a styrylpyrene-terminated three-armed star PDMS was prepared by introducing 1-(4-allyloxystyryl)pyrene as a styrylpyrene derivative into hydrosilane-terminated three-armed star PDMS with a number-average molecular weight Mn(RI) of 28,300 (D=1.40). The resulting PDMS was shown in the following formula:

[0049] Example 3: Using the same synthetic method as in Example 1 and adjusting the reaction conditions, a styrylpyrene-terminated three-armed star PDMS was prepared by introducing 1-(5-hexenyl ester styryl)pyrene as a styrylpyrene derivative into hydrosilane-terminated three-armed star PDMS with a number-average molecular weight Mn(RI) of 14,300 (D=1.12). The resulting compound had a number-average molecular weight Mn(RI) of 16,200 (D=1.20).

[0050] <Preparation of Compositions> Compositions containing a polymer compound and an oily solvent in Examples 4 to 6 were prepared as follows.

[0051] Example 4 The sample (50 mg) of Example 1 was added to silicone oil: KF-56A (117 mg, diphenylsiloxyphenyl trimethicone, manufactured by Shin-Etsu Chemical Co., Ltd.) and mixed to prepare a 30% by mass composition.

[0052] Example 5 The sample (50 mg) of Example 3 was added to silicone oil: KF-56A (117 mg) and mixed at 70° C. to prepare a 30% by mass composition.

[0053] Example 6 The sample (50 mg) of Example 3 was added to silicone oil: KF-96A-6T (117 mg, dimethicone, manufactured by Shin-Etsu Chemical Co., Ltd.) and mixed at 70° C. to prepare a 30% by mass composition.

[0054] <Evaluation of viscoelastic change> The sample of Example 2 was alternately irradiated with light of a wavelength of 436 nm (set intensity 80) and light of a wavelength of 330 nm (set intensity 80) using a filtered spectrum from a xenon light source (MAX-350, manufactured by Asahi Spectroscopy Co., Ltd.), and the storage modulus G' (Pa) and loss modulus G" (Pa) were measured over time. A rotational rheometer (MCR-102, manufactured by Anton Paar) was used for the measurement. The sample was applied to the surface of a glass lower plate to a thickness of 0.10 mm, and a parallel plate (diameter 12 mm) was placed on top and rotated at a frequency of 1 Hz.

[0055] Furthermore, the light irradiation was stopped when convergence of the change in viscoelasticity was observed, and then irradiation of light of a different wavelength was started and similarly stopped when convergence of the change in viscoelasticity was observed. More specifically, no light irradiation was performed from 0 to 60 seconds, light irradiation with a wavelength of 436 nm was performed from 60 to 3660 seconds, light irradiation with a wavelength of 330 nm was performed from 3660 to 4260 seconds, light irradiation with a wavelength of 436 nm was performed from 4260 to 4860 seconds, light irradiation with a wavelength of 330 nm was performed from 4860 to 5460 seconds, light irradiation with a wavelength of 436 nm was performed from 5460 to 6060 seconds, and light irradiation with a wavelength of 330 nm was performed from 6060 to 6660 seconds.

[0056] The evaluation results of Example 2 are shown in Figure 1. As shown in Figure 1, the viscoelasticity of all the styrylpyrene-terminated three-arm star-shaped PDMSs with different molecular weights repeatedly and reversibly changed when they were alternately irradiated with light of different wavelengths.

[0057] The compositions of Examples 4 to 6 were also evaluated for changes in viscoelasticity.

[0058] The results are shown in Figures 2 to 4. In all of these cases, when light of different wavelengths was alternately irradiated, the viscoelasticity repeatedly and reversibly changed.

[0059] Although the present invention has been described above based on specific embodiments and examples, these embodiments and examples are presented merely 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.

Claims

1. A compound characterized by having a partial structure in which styrylpyrene or a derivative thereof is bonded to at least one end of the main chain or side chain of a backbone polymer containing a polysiloxane structure.

2. The compound of claim 1, wherein the compound is reversibly changeable 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.

3. The compound according to claim 2, wherein: (i) by irradiating the compound with light of the first wavelength, an unsaturated double bond contained in a partial structure to which styrylpyrene or a derivative thereof is bonded is cleaved, forming a structure containing a cyclized adduct between the partial structures to which two styrylpyrenes or derivatives thereof are bonded, thereby entering the second state; and (ii) by irradiating the compound with light of the second wavelength, the structure containing the cyclized adduct is cleaved, separating into the partial structures to which two styrylpyrenes or derivatives thereof are bonded, thereby entering the first state.

4. The compound of claim 2, wherein the fluidity in said first state is greater than the fluidity in said second state.

5. The partial structure to which the styrylpyrene or its derivative is bonded is represented by the formula (a): (Wherein, L is a hydrocarbon chain, and —CH ２ - is an oxy (-O-) group, an ester (-CO-O-) group, or -SiR ２ -, and the hydrogens of the hydrocarbon chain may be replaced by -SiR ３ or halogen (wherein R is independently hydrogen or an alkyl group having 1 to 3 carbon atoms), the number of carbon atoms contained in L is 1 to 20, and R ａ２ are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a hydroxyl group, na2 is 0 to 4, and R ａ３ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms; R ａ４ are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a hydroxyl group; na4 is an integer of 0 to 10; and * indicates a bonding position to the backbone polymer.

6. The partial structure to which the styrylpyrene or its derivative is bonded is represented by formula (a-1) or (a-2): (In the formula, R ａ１ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and na1 is an integer of 2 to 8.

7. The backbone polymer is represented by the formula (b-1): Z-(PS1) ｎ１ -# (b-1) (wherein Z is a hydrocarbon group having a valence of n1, and each PS1 is independently a polysiloxane structure, and -SiR ｂ ２ O- (where R ｂ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms) is -(CR ｂ ' ２ ) ｎｂ’ - (where R ｂ’ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and nb' represents a group having 1 to 5 carbon atoms; n1 represents a group having 1 to 6 carbon atoms; and # represents a bonding position to an end group of a polysiloxane structure or to a partial structure to which the styrylpyrene or a derivative thereof is bonded.

8. The backbone polymer is represented by formula (b-2): PS2-# ｎ２ (b-2) (wherein, PS2 is a polysiloxane structure having a valence of n2, and —SiR ｂ ２ O- (where R ｂ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms) is -(CR ｂ ' ２ ) ｎｂ’ - (where R ｂ’ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and nb' represents a group having 1 to 5 carbon atoms; n2 represents a group having 1 to 10 carbon atoms; and # represents a bonding position to an end group of a polysiloxane structure or to a partial structure to which the styrylpyrene or a derivative thereof is bonded.

9. The backbone polymer containing a polysiloxane structure is represented by formula (b-1-1) or (b-1-2): (In the formula, R ｂ１ are each independently a hydrogen atom, an alkyl group, a halogen-substituted alkyl group, an alkenyl group, a halogen-substituted alkenyl group, an aryl group, or a halogen-substituted aryl group; nb1 is each independently 1 to 150; R ｂ’ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, nb' is 1 to 5, and # indicates the bonding position to the partial structure to which the styrylpyrene or a derivative thereof is bonded.

10. The compound according to claim 1, wherein the backbone polymer has a glass transition temperature of -130°C or higher and 0°C or lower.

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

12. The compound according to claim 1, wherein the first wavelength is 400 to 500 nm or more and the second wavelength is 380 nm or less.

13. A composition comprising a compound according to any one of claims 1 to 12 and an oily solvent.

14. The composition of claim 13, wherein the oily solvent comprises a silicone oil, a hydrocarbon oil, or a mixture thereof.

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