Film, electret material, vibration-type power generation element, and film production method

Abstract

The present invention provides: a film in which the amount of power generation that can be obtained when said film is applied, as an electret material, to a vibration-type power generation element is large, and which has excellent thermal stability of charges; an electret material using said film; a vibration-type power generation element; and a film production method. A film according to the present invention has the absolute value of the surface charge density being 0.5 mC / m2 or more, and the ratio of the elastic modulus at 150°C to the elastic modulus at 25°C being 0.6 or more.

Description

Film, electret material, vibration-type power generation element, and method for manufacturing film

[0001] The present invention relates to a film, an electret material, a vibration-type power generating element, and a method for manufacturing the film.

[0002] An electret material is a material that maintains semi-permanent electric polarization inside even when there is no external electric field, thereby forming an external electric field (exerting an electric force). More specifically, an electret material refers to a material in which a portion of a conventionally electrically impermeable polymeric material or inorganic material is semi-permanently polarized (macroscopically, electrostatically charged or retains an electric charge) by thermally or electrically treating the material. For example, Patent Document 1 discloses an electret material containing a thermoplastic resin.

[0003] JP 2016-039275 A

[0004] On the other hand, for a film applicable to an electret material, it is desirable that the amount of electricity generated is large when it is applied as an electret material to a vibration-type power generating element. Furthermore, it is also desirable for the film to have excellent thermal stability of charge. Excellent thermal stability of charge means that the film maintains a charged state even when heated (in other words, maintains an electrically polarized state). The present inventors investigated the properties of the material described in Patent Document 1 and found that it was not possible to achieve both the above-mentioned amount of electricity generated and the above-mentioned thermal stability of charge.

[0005] In view of the above circumstances, an object of the present invention is to provide a film that can generate a large amount of electricity when used as an electret material in a vibration-type power generating element and that also has excellent thermal stability of charge. Another object of the present invention is to provide an electret material, a vibration-type power generating element, and a method for manufacturing the film.

[0006] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration.

[0007] (1) The absolute value of the surface charge density is 0.5 mC / m ２or more, and the ratio of the elastic modulus at 150°C to the elastic modulus at 25°C is 0.6 or more. (2) The film according to (1), wherein the film contains an organic compound, and the content of the organic compound is 50 mass% or more with respect to the total mass of the film. (3) The film according to (1) or (2), wherein the film contains a cured product of a polymerizable liquid crystal compound. (4) The film according to (3), wherein the polymerizable liquid crystal compound has a plurality of aromatic ring groups selected from the group consisting of groups represented by formulas (Ar-1) to (Ar-5) described below. (5) The film according to (4), wherein the polymerizable liquid crystal compound is a compound represented by formula (1) described below. (6) The film according to any one of (1) to (5), wherein the relative dielectric constant is less than 10 at any wavelength in a measurement frequency range of 1 to 500 Hz. (7) An electret material comprising the film according to any one of (1) to (6). (8) A vibration type power generating element comprising the electret material according to (7). (9) A method for producing a film, comprising: Step 1 of applying an electric field to a polymerizable liquid crystal compound; and Step 2 of curing the polymerizable liquid crystal compound to obtain the film according to any one of (1) to (6).

[0008] According to the present invention, it is possible to provide a film that can generate a large amount of electricity when applied as an electret material to a vibration-type power generating element and that has excellent thermal stability of charge. Furthermore, according to the present invention, it is possible to provide an electret material, a vibration-type power generating element, and a method for manufacturing the film.

[0009] Fig. 1 is a diagram for explaining step 1. Fig. 2 is a diagram for explaining step 1. Fig. 3 is a diagram conceptually showing an example of a vibration type power generating element of the present invention. Fig. 4 is a diagram conceptually showing an example in which a counter electrode in a vibration type power generating element of the present invention is vibrated. Fig. 5 is a diagram conceptually showing another example of the vibration type power generating element of the present invention.

[0010] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in this specification, each component may be used alone or in combination of two or more substances corresponding to the component. Here, when two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified. The bonding direction of divalent groups expressed in this specification is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by "X-Y-Z," Y may be -CO-O- or -O-CO-. In other words, the compound may be "X-CO-O-Z" or "X-O-CO-Z."

[0011] In this specification, examples of the substituent include the substituents described below in Substituent Group A. In this specification, the phrase "optionally having a substituent" includes not only an embodiment in which no substituent is present, but also an embodiment in which one or more substituents are present. <Substituent Group A> Examples of the substituent include halogen atoms (for example, fluorine atoms, chlorine atoms, and bromine atoms, preferably chlorine atoms or fluorine atoms, more preferably fluorine atoms); alkyl groups (preferably linear, branched, or cyclic alkyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as linear alkyl groups having 1 to 6 carbon atoms (for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl), branched alkyl groups having 3 to 6 carbon atoms (for example, isopropyl, isobutyl, tert-butyl, sec-butyl, neopentyl, isohexyl, and 3-methylpentyl), and cyclic alkyl groups having 3 to 12 carbon atoms (for example, cyclopropyl, cyclopentyl, cyclohexyl, 1-norbornyl, and 1-adamantyl)); alkenyl groups (preferably alkenyl groups having 2 to 48 carbon atoms, more preferably 2 to 18 carbon atoms, such as vinyl, allyl, 1-butenyl, and 2-butenyl); alkynyl groups (preferably alkynyl groups having 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, such as ethynyl, 1-propynyl, propargyl, 1-butynyl, and 2-butynyl); aryl groups (preferably aryl groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, such as phenyl, oligoaryl groups (naphthyl, anthryl), phenanthrenyl, fluorenyl, pyrenyl, triphenylenyl, and biphenyl); heteroaryl groups (preferably heterocyclic groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as a 2-thienyl group, a 4-pyridyl group, a 2-furyl group, a 2-pyrimidinyl group, a 1-pyridyl group, a 2-benzothiazolyl group, a 1-imidazolyl group, a 1-pyrazolyl group, and a benzotriazol-1-yl group);arylalkyl groups (preferably arylalkyl groups having 7 to 15 carbon atoms, for example, benzyl, phenethyl, methylbenzyl, phenylpropyl, 1-methylphenylethyl, phenylbutyl, 2-methylphenylpropyl, tetrahydronaphthyl, naphthylmethyl, naphthylethyl, indenyl, fluorenyl, anthracenylmethyl (anthrylmethyl), and phenanthrenylmethyl (phenanthrylmethyl) groups); silyl groups (preferably silyl groups having 3 to 38 carbon atoms, more preferably 3 to 18 carbon atoms, for example, trimethylsilyl, triethylsilyl, tributylsilyl, t-butyldimethylsilyl, and t-hexyldimethylsilyl); hydroxy groups; cyano groups; nitro groups; morpholino groups; Alkoxy groups (preferably alkoxy groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as methoxy, ethoxy, 1-butoxy, 2-butoxy, isopropoxy, t-butoxy, dodecyloxy, and cycloalkyloxy groups (such as cyclopentyloxy and cyclohexyloxy)); aryloxy groups (preferably aryloxy groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, such as phenoxy and 1-naphthoxy); alkenyloxy groups (preferably alkenyloxy groups having 2 to 6 carbon atoms, such as vinyloxy, 1-propenyloxy, 2-n-propenyloxy (allyloxy), 1-n-butenyloxy, and prenyloxy); heterocyclic oxy groups (preferably heterocyclic oxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as 1-phenyltetrazole-5-oxy and 2-tetrahydropyranyloxy groups); silyloxy groups (preferably silyloxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as trimethylsilyloxy, t-butyldimethylsilyloxy and diphenylmethylsilyloxy groups); acyloxy groups (preferably acyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, such as acetoxy, pivaloyloxy, benzoyloxy, dodecanoyloxy, acryloyloxy and methacryloyloxy groups);hydroxyalkyleneoxy groups (preferably hydroxyalkyleneoxy groups having 2 to 10 carbon atoms, such as a hydroxyethyleneoxy group); alkoxycarbonyloxy groups (preferably alkoxycarbonyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, such as an ethoxycarbonyloxy group, a t-butoxycarbonyloxy group, and a cycloalkyloxycarbonyloxy group (such as a cyclohexyloxycarbonyloxy group)); aryloxycarbonyloxy groups (preferably aryloxycarbonyloxy groups having 7 to 32 carbon atoms, more preferably 7 to 24 carbon atoms, such as a phenoxycarbonyloxy group); carbamoyloxy groups (preferably carbamoyloxy groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as an N,N-dimethylcarbamoyloxy group, an N-butylcarbamoyloxy group, an N-phenylcarbamoyloxy group, and an N-ethyl-N-phenylcarbamoyloxy group); sulfamoyloxy groups (preferably sulfamoyloxy groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, such as N,N-diethylsulfamoyloxy groups and N-propylsulfamoyloxy groups); alkylsulfonyloxy groups (preferably alkylsulfonyloxy groups having 1 to 38 carbon atoms, more preferably 1 to 24 carbon atoms, such as methylsulfonyloxy groups, hexadecylsulfonyloxy groups and cyclohexylsulfonyloxy groups); arylsulfonyloxy groups (preferably arylsulfonyloxy groups having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, such as phenylsulfonyloxy groups); acyl groups (preferably acyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as formyl groups, acetyl groups, acryloyl groups, methacryloyl groups, pivaloyl groups, benzoyl groups, tetradecanoyl groups and cyclohexanoyl groups); an alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, an octadecyloxycarbonyl group, a cyclohexyloxycarbonyl group, and a 2,6-di-tert-butyl-4-methylcyclohexyloxycarbonyl group);an aryloxycarbonyl group (preferably an aryloxycarbonyl group having 7 to 32 carbon atoms, more preferably an aryloxycarbonyl group having 7 to 24 carbon atoms, for example, a phenoxycarbonyl group); a carbamoyl group (preferably a carbamoyl group having 1 to 48 carbon atoms, more preferably a carbamoyl group having 1 to 24 carbon atoms, for example, a carbamoyl group, N,N-diethylcarbamoyl group, N-ethyl-N-octylcarbamoyl group, N,N-dibutylcarbamoyl group, N-propylcarbamoyl group, N-phenylcarbamoyl group, N-methyl-N-phenylcarbamoyl group, and N,N-dicyclohexylcarbamoyl group); an amino group (preferably an amino group having 32 or less carbon atoms, more preferably an amino group having 24 or less carbon atoms, for example, amino, methylamino, N,N-dibutylamino, tetradecylamino, 2-ethylhexylamino, and cyclohexylamino group); anilino group (preferably an anilino group having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, for example, an anilino group and an N-methylanilino group); heterocyclic amino group (preferably a heterocyclic amino group having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, for example, a 4-pyridylamino group); carbonamido group (preferably a carbonamido group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, an acetamido group, a benzamido group, a tetradecanamido group, a pivaloylamido group and a cyclohexanamido group); ureido group (preferably a ureido group having 1 to 32 carbon atoms, more preferably a ureido group having 1 to 24 carbon atoms, for example, a ureido group, an N,N-dimethylureido group and an N-phenylureido group); imido group (preferably an imido group having 36 or less carbon atoms, more preferably 24 or less carbon atoms, for example, an N-succinimido group and an N-phthalimido group); an alkoxycarbonylamino group (preferably an alkoxycarbonylamino group having 2 to 48 carbon atoms, more preferably an alkoxycarbonylamino group having 2 to 24 carbon atoms, for example, a methoxycarbonylamino group, an ethoxycarbonylamino group, a t-butoxycarbonylamino group, an octadecyloxycarbonylamino group, and a cyclohexyloxycarbonylamino group); an aryloxycarbonylamino group (preferably an aryloxycarbonylamino group having 7 to 32 carbon atoms, more preferably an aryloxycarbonylamino group having 7 to 24 carbon atoms, for example, a phenoxycarbonylamino group);sulfonamido groups (preferably sulfonamido groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as methanesulfonamido groups, butanesulfonamido groups, benzenesulfonamido groups, hexadecanesulfonamido groups, and cyclohexanesulfonamido groups); sulfamoylamino groups (preferably sulfamoylamino groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as N,N-dipropylsulfamoylamino groups and N-ethyl-N-dodecylsulfamoylamino groups); azo groups (preferably azo groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, such as phenylazo groups and 3-pyrazolylazo groups); alkylthio groups (preferably alkylthio groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as methylthio groups, ethylthio groups, octylthio groups, and cyclohexylthio groups); an arylthio group (preferably an arylthio group having 6 to 48 carbon atoms, more preferably an arylthio group having 6 to 24 carbon atoms, for example, a phenylthio group); a heterocyclic thio group (preferably a heterocyclic thio group having 1 to 32 carbon atoms, more preferably a heterocyclic thio group having 1 to 18 carbon atoms, for example, a 2-benzothiazolylthio group, a 2-pyridylthio group, and a 1-phenyltetrazolylthio group); an alkylsulfinyl group (preferably an alkylsulfinyl group having 1 to 32 carbon atoms, more preferably an alkylsulfinyl group having 1 to 24 carbon atoms, for example, a dodecanesulfinyl group); an arylsulfinyl group (preferably an arylsulfinyl group having 6 to 32 carbon atoms, more preferably an arylsulfinyl group having 6 to 24 carbon atoms, for example, a phenylsulfinyl group); alkylsulfonyl groups (preferably alkylsulfonyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfonyl group, isopropylsulfonyl group, 2-ethylhexylsulfonyl group, hexadecylsulfonyl group, octylsulfonyl group, and cyclohexylsulfonyl group); arylsulfonyl groups (preferably arylsulfonyl groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, phenylsulfonyl group, and 1-naphthylsulfonyl group);sulfamoyl groups (preferably sulfamoyl groups having 32 or less carbon atoms, more preferably 24 or less carbon atoms, for example, a sulfamoyl group, an N,N-dipropylsulfamoyl group, an N-ethyl-N-dodecylsulfamoyl group, an N-ethyl-N-phenylsulfamoyl group, an N-cyclohexylsulfamoyl group, and an N-(2-ethylhexyl)sulfamoyl group); phosphonyl groups (preferably phosphonyl groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a phenoxyphosphonyl group, an octyloxyphosphonyl group, and a phenylphosphonyl group); phosphinoylamino groups (preferably phosphinoylamino groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a diethoxyphosphinoylamino group and a dioctyloxyphosphinoylamino group); an epoxy group; —NHCOCH; ３ ;-SO ２ NHC ２ H ４ OCH ３ ;-NHSO ２ CH ３ ; alkylcarbonyloxy group; etc., and two or more of these may be combined. These substituents may be further substituted with other substituents. Furthermore, when there are two or more substituents, they may be the same or different. Furthermore, if possible, they may be bonded to each other to form a ring.

[0012] The film of the present invention is characterized by having a surface charge density equal to or greater than a predetermined value and a ratio of elastic moduli at 25°C and 150°C equal to or greater than a predetermined value. First, because the surface charge density is large, when the film of the present invention is applied to a vibration-type power generation element, the amount of power generated is large. Furthermore, the elastic modulus ratio being equal to or greater than a predetermined value means that the elastic modulus of the film is unlikely to decrease even under high-temperature conditions, and a film with such characteristics is unlikely to soften even under high-temperature conditions. In such a film, the constraints on the charge in the film are unlikely to be released even under high-temperature conditions, resulting in easier charge retention and excellent thermal stability of the charge.

[0013] The film of the present invention (hereinafter also referred to simply as "the present film") has an absolute value of the surface charge density of 0.5 mC / m ２ The ratio of the elastic modulus at 150° C. to the elastic modulus at 25° C. is 0.6 or more. The film will be described in detail below.

[0014] The absolute value of the surface charge density of this film is 0.5 mC / m ２ This film has the advantage of being 1.0 mC / m in that it can generate more electricity when used as an electret material in a vibration-type power generating element. ２ More than 2.0 mC / m is preferable. ２ More preferably, 3.0 mC / m or more ２ The upper limit of the absolute value of the surface charge density of the present film is not particularly limited, but is preferably 10.0 mC / m ２ In most cases, it is less than 5.0 mC / m ２ The following cases are more common: The surface charge density of the film is measured using a Monroe Electronics surface potentiometer Model 244A manufactured by Kansai Electronics Co., Ltd., under atmospheric conditions of 25°C and 45% RH (relative humidity). The absolute value of the obtained value is taken as the absolute value of the surface charge density of the film of the present invention.

[0015] In this film, the ratio of the elastic modulus at 150°C to the elastic modulus at 25°C (elastic modulus at 150°C / elastic modulus at 25°C) is 0.6 or more, and is preferably 0.7 or more, more preferably 0.8 or more, and even more preferably 0.9 or more, in terms of better thermal stability of charge. The upper limit of the ratio of the elastic modulus at 150°C to the elastic modulus at 25°C of this film is not particularly limited, but is often 5.0 or less, more often 3.0 or less, and even more often 1.0 or less. The elastic modulus is measured as the indentation elastic modulus using a nanoindentation method. More specifically, the indentation modulus is measured using a microhardness tester (product name "DUH-W201" manufactured by Shimadzu Corporation) at 25°C and 150°C by applying a load to the film with a Vickers indenter at a loading rate of 0.28 mN / sec, holding a maximum load of 10 mN for 10 seconds, and then unloading at a loading rate of 0.28 mN / sec. The modulus is measured at three points on the side of the film at 5 μm intervals in the thickness direction, and the average of the measured values ​​is used as the modulus of elasticity for each film. Next, the ratio of the modulus of elasticity at 150°C to the modulus of elasticity at 25°C is calculated from the measured values.

[0016] The present film preferably has a dielectric constant of less than 10 at any wavelength between 1 and 500 Hz, since it provides at least one of the following effects when applied as an electret material to a vibration-type power generating element: a higher amount of power generated; and superior thermal stability of charge (hereinafter, simply referred to as "superior effects of the present invention"). In particular, the dielectric constant is preferably 5 or less, more preferably 2 or less. While the lower limit is not particularly limited, it is often greater than 0. Furthermore, the dielectric constant is preferably measured at a measurement frequency of 1 Hz. The dielectric constant is measured by a resonance perturbation method at a predetermined measurement frequency. A cavity resonator (CP531, manufactured by Kanto Electronics Application Development Co., Ltd.) with a predetermined measurement frequency is connected to a network analyzer (E8363B, manufactured by Agilent Technology Corporation), and the present film is inserted into the cavity resonator. The dielectric constant is measured from the change in resonance frequency before and after insertion for 96 hours in an environment of 25°C and 60% RH.

[0017] The thickness of the present film is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 50 μm, in terms of achieving better effects of the present invention. The thickness of the present film is a value obtained by measuring the thickness at 10 positions on the present film and calculating the arithmetic average of the measured values.

[0018] The composition of the present film is not particularly limited, but it preferably contains an organic compound, since the effects of the present invention are more excellent. The content of the organic compound in the present film is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the present film, since the effects of the present invention are more excellent. The upper limit of the content of the organic compound is not particularly limited, but it can be 100% by mass, based on the total mass of the film.

[0019] In order to obtain more excellent effects of the present invention, it is preferable that the present film contains a cured product of a polymerizable liquid crystal compound. In order to obtain more excellent effects of the present invention, the content of the cured product of the polymerizable liquid crystal compound in the present film is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the present film. The upper limit of the content of the cured product of the polymerizable liquid crystal compound is not particularly limited, but may be 100% by mass based on the total mass of the film.

[0020] A polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable group. Here, a liquid crystal compound refers to a compound that exhibits a liquid crystal state under specific temperature conditions. The specific temperature conditions vary depending on the type of liquid crystal compound, and are not particularly limited. In other words, a liquid crystal compound can also be said to be a compound having a temperature range in which it exhibits a liquid crystal state.

[0021] The number of polymerizable groups possessed by the polymerizable liquid crystal compound is not particularly limited, but is preferably 2 or more, and more preferably 2 to 4, in terms of achieving superior effects of the present invention. The polymerizable group is not particularly limited, but a radically polymerizable group or a cationically polymerizable group is preferred. As the radically polymerizable group, known radically polymerizable groups can be used, and an acryloyloxy group or a methacryloyloxy group is preferred. As the cationically polymerizable group, known cationically polymerizable groups can be used, and specific examples include an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester group, and a vinyloxy group. Among these, an alicyclic ether group or a vinyloxy group is preferred, and an epoxy group, an oxetanyl group, or a vinyloxy group is more preferred. Particularly preferred examples of the polymerizable group include polymerizable groups represented by any of the following formulas (P-1) to (P-20). Me represents a methyl group.

[0022]

[0023] The polymerizable liquid crystal compound is not particularly limited, but in terms of providing superior effects of the present invention, it preferably has a plurality of aromatic ring groups (hereinafter also simply referred to as "specific aromatic ring groups") selected from the group consisting of groups represented by formulas (Ar-1) to (Ar-5). The number of specific aromatic ring groups that the polymerizable liquid crystal compound has may be a plurality (2 or more), and in terms of providing superior effects of the present invention, it is preferably 2 to 8, more preferably 2 to 5, and even more preferably 2 to 3.

[0024]

[0025] In the above formulae (Ar-1) to (Ar-5), * represents a bonding position, that is, a bonding position to a portion other than the aromatic ring group contained in the polymerizable liquid crystal compound.

[0026] In addition, in the above formula (Ar-1), Q １ represents N or CH, and Q ２ is -S-, -O-, or -N(R ６ )-, R ６ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Y １represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, and -CH ２ One or more of - may be substituted with -O-, -S- or -NH-.

[0027] Here, R ６ Specific examples of the alkyl group having 1 to 6 carbon atoms represented by one embodiment of the formula (1) include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group.

[0028] Y １ Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms represented by one embodiment of the formula (1) include aryl groups such as a phenyl group, a 2,6-diethylphenyl group, and a naphthyl group. １ Examples of the aromatic heterocyclic group having 3 to 12 carbon atoms represented by one embodiment of the formula (1) include heteroaryl groups such as a thienyl group, a thiazolyl group, a furyl group, and a pyridyl group, as well as groups formed by removing one hydrogen atom from an indole ring, a benzofuran ring, a benzothiophene ring, a benzimidazole ring, a benzothiazole ring, and a benzoxazole ring. １ The aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y is preferably a group obtained by removing one hydrogen atom from a benzofuran ring or a benzothiazole ring. １ Examples of the alicyclic hydrocarbon group having 6 to 20 carbon atoms represented by one embodiment of the formula (1) include a cyclohexyl group, a cyclopentyl group, a norbornyl group, and an adamantyl group. １ Examples of the substituent that may be possessed by the group include the substituents described in the above-mentioned substituent group A, and among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0029] In addition, in the above formulas (Ar-1) to (Ar-5), Z １ , Z ２ and Z３ each independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a monovalent aromatic heterocyclic group having 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, -OR ７ , -NR ８ R ９ , -SR １０ , -COOR １１ , or -COR １２ represents R ７ ~R １２ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Z １ and Z ２ may be bonded to each other to form an aromatic ring.

[0030] As the monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alkyl group having 1 to 15 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, specifically, a methyl group, an ethyl group, an isopropyl group, a tert-pentyl group (1,1-dimethylpropyl group), a tert-butyl group, or a 1,1-dimethyl-3,3-dimethylbutyl group is further preferable, and a methyl group, an ethyl group, or a tert-butyl group is particularly preferable. Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, methylcyclohexyl, and ethylcyclohexyl groups; monocyclic unsaturated hydrocarbon groups such as cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclodecenyl, cyclopentadienyl, cyclohexadienyl, cyclooctadienyl, and cyclodecadiene; bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, tricyclo[5.2.1.0]heptyl, bicyclo[5.2.1.0]octyl, and tricyclo[5.2.1.0]diene; ２，６ ]decyl group, tricyclo[3.3.1.1 ３，７ ]decyl group, tetracyclo[6.2.1.1 ３，６ .0 ２，７] dodecyl group, and polycyclic saturated hydrocarbon groups such as adamantyl group; etc. Specific examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include phenyl group, 2,6-diethylphenyl group, naphthyl group, and biphenyl group, with aryl groups having 6 to 12 carbon atoms (particularly phenyl group) being preferred. Specific examples of monovalent aromatic heterocyclic groups having 6 to 20 carbon atoms include 4-pyridyl group, 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, and 2-benzothiazolyl group. Examples of halogen atoms include fluorine atom, chlorine atom, bromine atom, and iodine atom, with fluorine atom, chlorine atom, or bromine atom being preferred. On the other hand, R ７ ~R １２ Specific examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group.

[0031] Z １ and Z ２ As described above, may be bonded to each other to form an aromatic ring. For example, Z １ and Z ２ Examples of the structure in which Q are bonded to each other to form an aromatic ring include a group represented by the following formula (Ar-1a): In the following formula (Ar-1a), * represents the bonding position, and Q １ , Q ２ and Y １ The examples of the group include those similar to those explained in the above formula (Ar-1).

[0032]

[0033] In addition, in the above formulas (Ar-2) and (Ar-3), A ３ and A ４ are each independently —O—, —N(R １３ represents a group selected from the group consisting of —, —S—, and —CO—; R １３ represents a hydrogen atom or a substituent. １３Examples of the substituent represented by one embodiment of the formula (1) include the substituents described in the above-mentioned Substituent Group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0034] In the formula (Ar-2), X represents a nonmetallic atom of Groups 14 to 16. However, the nonmetallic atom may have a hydrogen atom or a substituent bonded thereto. Examples of the nonmetallic atom of Groups 14 to 16 represented by X include an oxygen atom, a sulfur atom, a hydrogen atom, or a nitrogen atom bonded to a substituent [=N-R Ｎ１ , R Ｎ１ represents a hydrogen atom or a substituent.], a carbon atom to which a hydrogen atom or a substituent is bonded [═C(R Ｃ１ ) ２ , R Ｃ１ represents a hydrogen atom or a substituent.] Examples of the substituent include the substituents described in the above-mentioned substituent group A, and among them, an alkyl group, an alkoxy group, an alkyl-substituted alkoxy group, an aryl group (for example, a phenyl group, a naphthyl group, etc.), a cyano group, an amino group, a nitro group, an alkylcarbonyl group, a sulfo group, or a hydroxy group is preferred.

[0035] In addition, in the above formula (Ar-3), D ５ and D ６ each independently represents a single bond, or —CO—, —O—, —S—, —C(═S)—, or —CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof, R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms.

[0036] Here, D ５ and D ６ Examples of the divalent linking group in one embodiment include -CO-, -O-, -CO-O-, -C(=S)O-, and -CR １ R ２ -, -CR １ R ２-CR １ R ２ -, -O-CR １ R ２ -, -CR １ R ２ -O-CR １ R ２ -, -CO-O-CR １ R ２ -, -O-CO-CR １ R ２ -, -CR １ R ２ -O-CO-CR １ R ２ -, -CR １ R ２ -CO-O-CR １ R ２ -, -NR ５ -CR １ R ２ -, and -CO-NR ５ - and so on. １ , R ２ and R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. Among these, any of —CO—, —O—, and —CO—O— is preferred.

[0037] In addition, in the above formula (Ar-3), SP ３ and SP ４ each independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that —CH ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. Examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0038] Examples of divalent aliphatic hydrocarbon groups having 1 to 20 carbon atoms include linear or branched alkylene groups having 1 to 20 carbon atoms, linear or branched alkenylene groups having 1 to 20 carbon atoms, and linear or branched alkynylene groups having 1 to 20 carbon atoms. As the linear or branched alkylene group having 1 to 20 carbon atoms, an alkylene group having 1 to 12 carbon atoms is preferred, and an alkylene group having 1 to 10 carbon atoms is more preferred, such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group. As the linear or branched alkenylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 10 carbon atoms is preferred, and an alkenylene group having 2 to 4 carbon atoms is more preferred, such as an ethenylene group. As the linear or branched alkynylene group having 1 to 20 carbon atoms, an alkynylene group having 2 to 10 carbon atoms is preferable, and an alkynylene group having 2 to 4 carbon atoms is more preferable, and an ethynylene group is exemplified. ３ and SP ４ As described above, represents —CH , which constitutes an aliphatic hydrocarbon group. ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-, and examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A. Among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0039] In addition, in the above formula (Ar-3), L ３ and L ４ each independently represents a monovalent organic group. ３ and L ４Examples of the monovalent organic group represented by the formula (I) include an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, a cyano group, and a carboxy group. The alkyl group may be linear, branched, or cyclic, but is preferably linear. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20, and even more preferably 1 to 10. The aryl group may be monocyclic or polycyclic, but is preferably monocyclic. The aryl group preferably has 6 to 25 carbon atoms, more preferably 6 to 10. The heteroaryl group may be monocyclic or polycyclic. The number of heteroatoms constituting the heteroaryl group is preferably 1 to 3. The heteroatom constituting the heteroaryl group is preferably a nitrogen atom, a sulfur atom, or an oxygen atom. The heteroaryl group preferably has 6 to 18 carbon atoms, more preferably 6 to 12. The alkyl group, aryl group, and heteroaryl group may be unsubstituted or may have a substituent. Examples of the substituent include those described in the above-mentioned substituent group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable. In addition, the monovalent organic group may be a polymerizable group. Examples of the polymerizable group include the groups exemplified as the polymerizable group possessed by the polymerizable liquid crystal compound.

[0040] In the above formulas (Ar-4) to (Ar-5), Ax represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles. In the above formulas (Ar-4) to (Ar-5), Ay represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, or an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles. Here, the aromatic rings in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring. In addition, Q ３ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may have a substituent. Examples of Ax and Ay include those described in paragraphs

[0039] to

[0095] of WO 2014 / 010325.３ The alkyl group having 1 to 20 carbon atoms represented by is preferably an alkyl group having 1 to 6 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. Examples of the substituent include the substituents described in the above-mentioned substituent group A. Among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred.

[0041] In order to obtain a more excellent effect of the present invention, the polymerizable liquid crystal compound is preferably a compound represented by the following formula (1).

[0042]

[0043] Here, in formula (1), D １ , D ２ , D ３ and D ４ each independently represents a single bond, or —CO—, —O—, —S—, —C(═S)—, or —CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof, R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. １ A Ｇ or SP Ｇ Represents. A １ , A ２ and A Ｇ each independently represents an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, or a divalent alicyclic hydrocarbon group which may have a substituent, provided that -CH ２ One or more of - may be substituted with -O-, -S- or -NH-. １ , SP ２ and SP Ｇeach independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that —CH ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. L １ and L ２ each independently represents a monovalent organic group; １ and L ２ At least one of Ar represents a polymerizable group. １ and Ar ２ When at least one of the following is an aromatic ring group represented by the following formula (Ar-3), L １ and L ２ and L in the following formula (Ar-3): ３ and L ４ At least one of the groups represented by m represents a polymerizable group. m represents an integer of 0 to 2. When m is 2, a plurality of G １ may be the same or different, and a plurality of D １ may be the same or different. l and n each independently represent 0 or an integer of 1 or more. When l is an integer of 2 or more, a plurality of A １ may be the same or different, and a plurality of D ３ may be the same or different. When n is an integer of 2 or more, a plurality of D ４ may be the same or different, and a plurality of A ２ may be the same or different, and p represents an integer of 1 or more. １ and Ar ２ each independently represents an aromatic ring group selected from the group consisting of groups represented by formulae (Ar-1) to (Ar-5).

[0044] In the above formula (1), D １ , D ２ , D ３ and D ４ Examples of the divalent linking group represented by one embodiment of the formula (I) include -CO-, -O-, -CO-O-, -C(=S)O-, and -CR １ R ２ -, -CR１ R ２ -CR １ R ２ -, -O-CR １ R ２ -, -CR １ R ２ -O-CR １ R ２ -, -CO-O-CR １ R ２ -, -O-CO-CR １ R ２ -, -CR １ R ２ -O-CO-CR １ R ２ -, -CR １ R ２ -CO-O-CR １ R ２ -, -NR ５ -CR １ R ２ -, and -CO-NR ５ - and so on. １ , R ２ and R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. Among these, any of —CO—, —O—, and —CO—O— is preferred.

[0045] In the above formula (1), A １ , A ２ and A Ｇ (G １ A as one aspect of Ｇ The same applies hereinafter.) is an aromatic hydrocarbon ring represented by one embodiment thereof, for example, an aromatic hydrocarbon ring having 6 to 20 carbon atoms, and specific examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthroline ring. １ , A ２ and A Ｇ Examples of the aromatic heterocycle represented by one embodiment of the formula (I) include aromatic heterocycles having 5 to 20 carbon atoms, and specific examples thereof include a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring. １ , A ２ and AＧ The divalent alicyclic hydrocarbon group represented by one embodiment of the formula (I) is preferably a 5-membered or 6-membered ring. The divalent alicyclic hydrocarbon group may be saturated or unsaturated, but is preferably a divalent saturated alicyclic hydrocarbon group. The —CH ２ One or more of the - may be substituted with -O-, -S-, or -NH-. Examples of such divalent alicyclic hydrocarbon groups include divalent alicyclic hydrocarbon groups having 5 to 12 carbon atoms, and specific examples include monocyclic hydrocarbon groups and bridged cyclic hydrocarbon groups, and more specific examples include those represented by the following formulas (g-1) to (g-10).

[0046]

[0047] In addition, in the above formula (1), A １ , A ２ and A Ｇ With regard to the above, examples of the substituent that the aromatic hydrocarbon ring, aromatic heterocycle, or divalent alicyclic hydrocarbon group may have include the substituents described in the above-mentioned Substituent group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0048] In the above formula (1), SP １ , SP ２ and SP Ｇ (G １ SP as one aspect of ＧThe same applies hereinafter.) Examples of the divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by one embodiment include a linear or branched alkylene group having 1 to 20 carbon atoms, a linear or branched alkenylene group having 1 to 20 carbon atoms, and a linear or branched alkynylene group having 1 to 20 carbon atoms. As the linear or branched alkylene group having 1 to 20 carbon atoms, an alkylene group having 1 to 12 carbon atoms is preferred, and an alkylene group having 1 to 10 carbon atoms is more preferred, such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group. As the linear or branched alkenylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 10 carbon atoms is preferred, and an alkenylene group having 2 to 4 carbon atoms is more preferred, such as an ethenylene group. As the linear or branched alkynylene group having 1 to 20 carbon atoms, an alkynylene group having 2 to 10 carbon atoms is preferable, and an alkynylene group having 2 to 4 carbon atoms is more preferable, and an ethynylene group is exemplified. １ , SP ２ and SP Ｇ As described above, represents —CH , which constitutes an aliphatic hydrocarbon group. ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-, and examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A. Among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0049] G in the above formula (1) １ However, the above-mentioned A Ｇ or SP Ｇ Among them, A Ｇ In addition, in order to improve solubility, it is preferable that G in the above formula (1) １ It is preferable that G in the above formula (1) represents a cycloalkane ring or a cycloalkene ring. １is a divalent alicyclic hydrocarbon group, and the ring constituting the divalent alicyclic hydrocarbon group is preferably a cycloalkane ring or a cycloalkene ring. Specific examples of the cycloalkane ring include a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclododecane ring, and a cyclodocosane ring. Specific examples of the cycloalkene ring include a cyclobutene ring, a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, a cyclooctene ring, a cyclopentadiene ring, and a cyclohexadiene ring.

[0050] In the above formula (1), L １ and L ２ The monovalent organic group represented by L ３ and L ４ Examples of the monovalent organic group represented by the formula (I) include the groups exemplified above.

[0051] In the above formula (1), L １ and L ２ Examples of the polymerizable group represented by at least one of the above include the groups exemplified as the polymerizable group possessed by the polymerizable liquid crystal compound.

[0052] In order to improve the durability of the film, L in the above formula (1) １ and L ２ However, each of them is preferably a polymerizable group, and more preferably an acryloyloxy group or a methacryloyloxy group.

[0053] In the above formula (1), m represents an integer of 0 to 2, l and n each independently represent 0 or an integer of 1 or more, and p represents an integer of 1 or more. Here, m is preferably 0 or 1, and from the viewpoint of synthesis, it is more preferably 1. In terms of solubility and compatibility with other liquid crystal compounds, l and n are preferably integers of 0 to 2. p is preferably an integer of 1 to 5, and more preferably an integer of 1 to 3. In the above formula (1), l and n both represent 1, and A １ and A ２ Preferably, each of these represents a benzene ring.

[0054] In formula (1), G in formula (1) １ , D １ and D ２ In the above formula (1), ２ It is preferable to exclude an embodiment in which Ar represents a single bond and m represents 0. That is, in the present invention, １ and Ar ２ is preferably excluded from the embodiment in which it is linked by a single bond.

[0055] On the other hand, in the above formula (1), Ar １ and Ar ２ each independently represents an aromatic ring group selected from the group consisting of groups represented by formulae (Ar-1) to (Ar-5).

[0056] The compound represented by the formula (1) above includes compounds represented by the following formulas (I) to (XII). Specifically, D １ , G １ , D ２ and K are compounds having the groups shown in Tables 1 to 8 below, and D in the following formulas (VII) to (XII) １ , G １ , G １ and D ２ and K are compounds having the groups shown in Table 9 below. １ The "*" in groups such as these indicates the bonding position. In the following description, a compound represented by the following formula (I) and having the group shown in 1-1 in Table 1 below will be referred to as "compound (I-1-1)," and compounds having other structural formulas and groups will be referred to in the same manner. For example, a compound represented by the following formula (II) and having the group shown in 2-3 in Table 2 below can be referred to as "compound (II-2-3)." In addition, the group adjacent to the acryloyloxy group in compound (I-1-1) and the like represents a propylene group (a group in which a methyl group is substituted with an ethylene group), and represents a mixture of positional isomers in which the position of the methyl group differs.

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] <Film Manufacturing Method> The method for manufacturing the present film is not particularly limited, but a film manufacturing method including step 1 of applying an electric field to a polymerizable liquid crystal compound and step 2 of obtaining the present film by curing the polymerizable liquid crystal compound obtained in step 1 is preferred. The procedure of each step will be described in detail below.

[0067] (Step 1) Step 1 is a step of applying an electric field to the polymerizable liquid crystal compound. By performing this step, the polymerizable liquid crystal compound is oriented and polarized in a predetermined direction, increasing the surface charge density. More specifically, FIG. 1 illustrates an example of a polymerizable rod-shaped liquid crystal compound having two specific aromatic ring groups. As shown in FIG. 1, the two specific aromatic ring groups in the polymerizable rod-shaped liquid crystal compound LC are polarized with positive and negative charges in a direction perpendicular to the long axis direction of the polymerizable rod-shaped liquid crystal compound LC. Before performing step 1, the polymerizable rod-shaped liquid crystal compound LC is oriented in various directions, and the polarization directions of the specific aromatic ring groups are also oriented in various directions. In contrast, after performing step 1, the polymerizable rod-shaped liquid crystal compound LC itself is oriented in a predetermined direction, and the polarization directions of the specific aromatic ring groups are also aligned, as shown in FIG. 2. As a result, the surface charge density increases on the surface of the resulting material containing the polymerizable rod-shaped liquid crystal compound LC. As will be described later, the orientation of the polymerizable liquid crystal compound can be fixed by applying an electric field to the polymerizable liquid crystal compound in a heated environment and then returning the temperature to room temperature. Fixing the orientation of the polymerizable liquid crystal compound can further reduce the relative dielectric constant of the resulting film.

[0068] An electric field is applied to the polymerizable liquid crystal compound. The form of the polymerizable liquid crystal compound is not particularly limited, but is preferably in the form of a film. That is, it is preferable to apply an electric field to a film containing a polymerizable liquid crystal compound. The thickness of the film containing a polymerizable liquid crystal compound is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 50 μm, in terms of achieving better effects of the present invention. The thickness of the film containing a polymerizable liquid crystal compound is a value obtained by measuring the thickness at 10 positions on the film containing the polymerizable liquid crystal compound and arithmetically averaging the measured thicknesses. The method for producing a film containing a polymerizable liquid crystal compound is not particularly limited, but a method of producing a film by applying a solution containing a polymerizable liquid crystal compound onto a substrate is preferred.

[0069] The method for applying an electric field to the polymerizable liquid crystal compound is not particularly limited, but examples include a method in which a film containing the polymerizable liquid crystal compound is placed between opposing electrodes and a voltage is applied between the electrodes to apply an electric field to the polymerizable liquid crystal compound. The conditions for applying an electric field to the polymerizable liquid crystal compound are not particularly limited, as long as the conditions are such that the above-mentioned film can be obtained. The voltage when applying the electric field is not particularly limited, but is preferably 0.5 to 10 kV, more preferably 2 to 5 kV. The application time of the electric field is not particularly limited, but is preferably 0.1 to 10 hours, more preferably 0.5 to 3 hours.

[0070] When an electric field is applied to the polymerizable liquid crystal compound, it is preferably carried out in a heated environment. By applying an electric field to the polymerizable liquid crystal compound in a heated environment, the polymerizable liquid crystal compound becomes more likely to be oriented, and the surface charge density becomes larger. The temperature of the heated environment when applying an electric field to the polymerizable liquid crystal compound is preferably equal to or higher than the glass transition temperature of the polymerizable liquid crystal compound. More specifically, the temperature is preferably 100 to 250°C, and more preferably 120 to 180°C.

[0071] After applying an electric field to the polymerizable liquid crystal compound in a heated environment, the polymerizable liquid crystal compound may be allowed to stand in a room temperature environment.

[0072] (Step 2) Step 2 is a step of curing the polymerizable liquid crystal compound obtained in Step 1 to obtain the present film. In this step, the polymerizable groups of the polymerizable liquid crystal compound are polymerized to harden the polymerizable liquid crystal compound, thereby immobilizing the liquid crystal compound and, as a result, further immobilizing the charge, thereby obtaining the present film having a predetermined surface charge density. Note that, by carrying out the above curing, the relative dielectric constant of the present film can be further reduced, and as a result, the amount of power generation can be increased.

[0073] The method for curing the polymerizable liquid crystal compound is not particularly limited, and known curing methods can be used. Examples of curing methods include photocuring and thermal curing, with photocuring being preferred. Photocuring is a method in which the polymerizable liquid crystal compound is irradiated with light of a specific wavelength, and ultraviolet light is preferably used to cure the polymerizable liquid crystal compound. The irradiation time of light (especially ultraviolet light) during photocuring is not particularly limited, but the longer the irradiation time, the more the curing progresses and the more the liquid crystal compound is fixed, resulting in improved thermal stability of the charge. The irradiation time is preferably 1 minute or more, more preferably 3 minutes or more. The upper limit is not particularly limited, but is often 20 minutes or less. When curing the polymerizable liquid crystal compound (e.g., when photocuring), the curing process may be performed while applying an electric field. The electric field application conditions (e.g., the applied electric field strength) can be those described in step 1.

[0074] <Electret Material and Vibration-Type Power Generating Element> The present film can be used for various purposes, but is particularly suitable as an electret material. Furthermore, an electret material formed from the present film can be suitably used for a vibration-type power generating element.

[0075] FIG. 3 is a diagram showing an example of a vibration power generating element. The vibration power generating element 10 shown in FIG. 3 includes an electret material 12 and a counter electrode 14 disposed opposite the electret material 12. The electret material 12 and the counter electrode 14 are electrically connected via wiring 16. The electret material 12 has a positive charge on its surface. Therefore, a negative charge is generated on the surface of the counter electrode 14. In the vibration power generating element 10, as shown in FIG. 4, by vibrating the counter electrode 14 in a direction perpendicular to the direction in which the counter electrode 14 and the electret material 12 face each other, the negative charge on the surface of the counter electrode 14 moves along the wiring 16, thereby generating a current.

[0076] The material constituting the counter electrode is not particularly limited, and known conductive materials can be used. Furthermore, although not shown in FIG. 3 , a conductive substrate for supporting the electret material 12 may be disposed between the electret material 12 and the wiring 16. Although only one counter electrode 14 facing the electret material 12 is shown in FIG. 3 , multiple counter electrodes may be provided. For example, in the vibration power generating element 20 shown in FIG. 5 , two counter electrodes 14A and 14B are disposed. In this vibration power generating element 20, the electret material 12 disposed in a position facing the counter electrode 14A moves in the direction of the white arrow, moves to face the counter electrode 14B, and then returns to its original position facing the counter electrode 14A. This vibration operation is repeated, and current can be generated from each counter electrode.

[0077] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0078] <Preparation of Films A-1 to A-3> SM-C (40.3 mmol), 4-(4-carboxycyclohexyl)cyclohexanecarboxylic acid (SM-B) (19.7 mmol), and 50 ml of dichloromethane were added to a 200 ml three-neck flask and stirred, followed by the addition of 3-(ethyliminomethyleneamino)-N,N-dimethyl-propan-1-amine; hydrochloride (59.0 mmol) and 4-dimethylaminopyridine (3.9 mmol), followed by stirring at room temperature for 3 hours. 100 ml of water was added to the resulting reaction solution and stirred, after which the aqueous phase was removed, and 200 ml of ethanol was added to precipitate a solid, which was then collected by filtration. The collected solid was dried to obtain Intermediate M-1. Intermediate M-1 (1.21 mmol), SM-A (2.48 mmol), and 10 mL of dichloromethane were added to a 100 mL three-neck flask and stirred. 3-(ethyliminomethyleneamino)-N,N-dimethyl-propan-1-amine; hydrochloride (3.63 mmol), and 4-dimethylaminopyridine (0.24 mmol) were then added and stirred at room temperature for 2 hours. 20 mL of water was added to the resulting reaction solution and stirred, after which the aqueous phase was removed and 20 mL of methanol was added to precipitate a solid, which was then filtered off. The filtered solid was dried overnight to obtain polymerizable liquid crystal compound L represented by the above formula (L1-3).

[0079]

[0080] Polymerizable liquid crystal compound L was dissolved in dichloromethane, and the resulting solution was applied to a copper plate so that the film thickness after drying would be 20 μm. The resulting coating film was then dried at 100° C. to obtain precursor films A-1 to A-3. Next, precursor films A-1 to A-3 were inserted into a thermostatic chamber placed between two opposing electrodes, and an electric field of 4 kV was applied at 150° C. for 1 hour. After that, while applying the electric field, 100 mW / cm ２ The liquid crystal composition was cured by irradiating it with ultraviolet light of 1000 kJ / cm for the time shown in Table 1, to obtain films A-1 to A-3.

[0081] <Preparation of Film A-4> Perfluoro(butenyl vinyl ether) and perfluoro(2,2-dimethyl-1,3-dioxole) were polymerized, followed by heat treatment at 330°C for 5 hours, and the resulting product was immersed in water to obtain Precursor A-4. The resulting Precursor A-4 was dissolved in perfluorotributylamine, and the resulting solution was applied to a copper plate so that the film would have a dry thickness of 20 μm. The resulting coating was dried at 180°C to obtain Precursor Film A-4. An electric charge was injected into Precursor Film A-4 by corona discharge, and Film A-4 was obtained.

[0082] <Preparation of Film A-5> The liquid crystal composition L was dissolved in dichloromethane. The resulting solution was applied to a glass plate having a polyimide alignment film that had been subjected to a homogeneous alignment treatment so that the film would have a dry thickness of 20 μm. The resulting coating was then dried at 100° C. to obtain precursor film A-5. Precursor film A-5 was exposed to light for the time shown in Table 1 to obtain film A-5.

[0083] <Preparation of Film A-6> Film A-6 was obtained by injecting charge into the above film A-5 by corona discharge.

[0084] <Surface Charge Density> The surface charge density of the obtained Films A-1 to A-6 (immediately after the corona discharge treatment) was measured in the atmosphere using a Monroe Electronics surface potentiometer Model 244A manufactured by Kansai Electronics Co., Ltd. The absolute values ​​of the obtained values ​​are shown in Table 10.

[0085] <Elastic Modulus> The elastic modulus of the obtained films A-1 to A-6 was measured as the indentation elastic modulus using the nanoindentation method. The indentation elastic modulus was measured using a microhardness tester (product name "DUH-W201", manufactured by Shimadzu Corporation) at 25°C and 150°C by applying a load to the film with a Vickers indenter at a loading rate of 0.28 mN / sec, holding a maximum load of 10 mN for 10 seconds, and then unloading at a loading rate of 0.28 mN / sec. The elastic modulus was measured at three points on the side of each film at 5 μm intervals in the thickness direction, and the average of the measured values ​​was used as the elastic modulus of each film. Next, the ratio of the elastic modulus at 150°C to the elastic modulus at 25°C was calculated from the measured values. The results are shown in Table 10.

[0086] <Dielectric Constant> The dielectric constant of the obtained films A-1 to A-6 was measured by the following method. The dielectric constant was measured by a resonance perturbation method at a frequency of 10 GHz. A 10 GHz cavity resonator ("CP531" manufactured by Kanto Electronics Application Development Co., Ltd.) was connected to a network analyzer ("E8363B" manufactured by Agilent Technology Corporation), and films A-1 to A-6 were inserted into the cavity resonator. The change in resonance frequency before and after insertion for 96 hours was measured in an environment of a temperature of 25°C and a humidity of 60% RH. The results are shown in Table 10.

[0087] <Power Generation Amount> Assuming that the above films A-1 to A-6 were applied to the vibration type power generating element having 30 counter electrodes as described in Fig. 5, the power generation amount Pmax of the obtained vibration type power generating element was calculated using the following formula. The results are shown in Table 10.

[0088]

[0089] σ: surface charge density of the film (C / m ２ ) n: number of counter electrodes d: film thickness (m) S: maximum overlapping area between the film and counter electrodes (m ２ ) f: vibration frequency (Hz) g: distance between the film and the counter electrode (m) ε: relative dielectric constant of the film ε ０ : Dielectric constant of air The number of the counter electrodes is 30, and the maximum overlapping area between the film and the counter electrode is 400 mm２ , the vibration frequency is 1 Hz, the distance (m) between the film and the counter electrode is 200 μm, and the dielectric constant of air is 8.85 × 10 －１２ The power generation amount was calculated as F / m.

[0090] <Thermal Stability of Charge> In the present disclosure, the thermal stability of charge is evaluated by the following method (thermal stimulated discharge method). After placing a counter electrode opposite each film, the current value flowing from the counter electrode was measured while the temperature was raised at 1°C / min to determine the discharge initiation temperature. The obtained results were evaluated based on the following evaluation criteria. The results are shown in Table 10. A higher discharge initiation temperature indicates better thermal stability. A: 180°C or higher B: 150°C or higher and lower than 180°C C: Lower than 150°C

[0091]

[0092] As shown in Table 10, it was confirmed that the desired effects could be obtained by using the film of the present invention. A comparison between Examples 1 and 2 confirmed that when the elastic modulus ratio was 0.8 or more, the thermal stability of the charge was better.

[0093] 10, 20 Vibration type power generating element 12 Electret material 14, 14A, 14B Counter electrode 16 Wiring

Claims

1. The absolute value of the surface charge density is 0.5 mC / m ２ or greater, and the ratio of the elastic modulus at 150°C to the elastic modulus at 25°C is 0.6 or greater.

2. The film according to claim 1, wherein the film contains an organic compound, and the content of the organic compound is 50% by mass or more relative to the total mass of the film.

3. The film according to claim 1, wherein the film comprises a cured product of a polymerizable liquid crystal compound.

4. The film according to claim 3, wherein the polymerizable liquid crystal compound has a plurality of aromatic ring groups selected from the group consisting of groups represented by formulae (Ar-1) to (Ar-5). In the formulae (Ar-1) to (Ar-5), * represents a bonding position. １ represents N or CH. ２ is -S-, -O-, or -N(R ６ )-, R ６ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. １ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, provided that -CH ２ One or more of - may be substituted with -O-, -S- or -NH-. １ , Z ２ and Z ３ each independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a monovalent aromatic heterocyclic group having 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, -OR ７ , -NR ８ R ９ , -SR １０ , -COOR １１ , or -COR １２ represents R ７ ~R １２ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Z １ and Z ２ may be bonded to each other to form an aromatic ring. ３ and A ４ are each independently —O—, —N(R １３ represents a group selected from the group consisting of —, —S—, and —CO—; R １３ represents a hydrogen atom or a substituent. X represents a non-metallic atom of Groups 14 to 16. However, the non-metallic atom may be bonded to a hydrogen atom or a substituent. D ５ and D ６ each independently represents a single bond, or —CO—, —O—, —S—, —C(═S)—, or —CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof, R １ ~R ５ SP each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. ３ and SP ４ each independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that the —CH ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. L ３ and L ４ each independently represents a monovalent organic group. Ax represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles. Ay represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, or an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles. The aromatic rings in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring. Q ３ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may have a substituent.

5. The film according to claim 4, wherein the polymerizable liquid crystal compound is a compound represented by formula (1). Here, in the formula (1), D １ , D ２ , D ３ and D ４ each independently represents a single bond, or —CO—, —O—, —S—, —C(═S)—, or —CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof, R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. １ A Ｇ or SP Ｇ Represents. A １ , A ２ and A Ｇ each independently represents an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, or a divalent alicyclic hydrocarbon group which may have a substituent, provided that -CH ２ One or more of - may be substituted with -O-, -S- or -NH-. １ , SP ２ and SP Ｇ each independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that the —CH ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. L １ and L ２ each independently represents a monovalent organic group; １ and L ２ At least one of Ar represents a polymerizable group. １ and Ar ２ When at least one of the following is an aromatic ring group represented by the following formula (Ar-3), L １ and L ２ and L in the following formula (Ar-3): ３ and L ４ At least one of the groups represented by m represents a polymerizable group. m represents an integer of 0 to 2. When m is 2, a plurality of G １ may be the same or different, and a plurality of D １ may be the same or different. l and n each independently represent 0 or an integer of 1 or more. When l is an integer of 2 or more, a plurality of A １ may be the same or different, and a plurality of D ３ may be the same or different. When n is an integer of 2 or more, a plurality of D ４ may be the same or different, and a plurality of A ２ may be the same or different, and p represents an integer of 1 or more. １ and Ar ２ each independently represents an aromatic ring group selected from the group consisting of groups represented by formulas (Ar-1) to (Ar-5).

6. The film according to claim 1, which has a relative dielectric constant of less than 10 at any wavelength within a measurement frequency range of 1 to 500 Hz.

7. An electret material comprising the film according to any one of claims 1 to 6.

8. A vibration-type power generating element comprising the electret material according to claim 7.

9. A method for producing a film, comprising: step 1 of applying an electric field to a polymerizable liquid crystal compound; and step 2 of curing the polymerizable liquid crystal compound to obtain the film according to claim 1.

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