Organic crystal, light guide plate, and eyepiece

Abstract

The present invention relates to an organic crystal which is a co-crystal (AB) of one or more aromatic compounds (A) and one or more aromatic compounds (B), a co-crystal (BB) of two or more aromatic compounds (B), or a single crystal (B) of one aromatic compound (B), wherein: the aromatic compound (A) has two or more aromatic rings, and an electron-withdrawing group is not bonded to the aromatic rings; and the aromatic compound (B) has one or more aromatic rings, and an electron-withdrawing group is bonded to each of the aromatic rings.

Description

Organic crystal, light guide plate, and eyepiece

[0001] The present invention relates to an organic crystal, a light guide plate, and an eyepiece. This application claims priority to Japanese Patent Application No. 2024-191055 filed in Japan on October 30, 2024, the content of which is incorporated herein by reference.

[0002] In wearable devices such as head-mounted displays that realize AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), etc., as a light guide plate, high refractive index properties and high transmittance properties for visible light are required.

[0003] As a glass having high refractive index properties and high transmittance properties for visible light, Patent Document 1 discloses that, in terms of mol% based on oxides, Bi ２ O ３ > 11.2%, and contains one or more selected from the group consisting of TeO ２ , TiO ２ , WO ３ , Nb ２ O ５ and Bi ２ O ３ , 3.78 ≤ Nb ２ O ５ / (TeO ２ + TiO ２ + WO ３ + Nb ２ O ５ + Bi ２ O ３ ) × 100 ≤ 19.2, and the total content of Fe, Cr, and Ni is less than 4 ppm in mass representation, a glass is disclosed.

[0004] International Publication No. 2022 / 059355

[0005] A further optical material with higher refractive index properties is required. An object of the present invention is to provide an organic crystal with higher refractive index properties, a light guide plate including the organic crystal, and an eyepiece including the light guide plate.

[0006] The present invention has the following embodiments: [1] An organic crystal which is a cocrystal (AB) of one or more aromatic compounds (A) and one or more aromatic compounds (B), a cocrystal (BB) of two or more of the aromatic compounds (B), or a single crystal (B) of one of the aromatic compounds (B), wherein the aromatic compound (A) has two or more aromatic rings and no electron-withdrawing groups are bonded to the aromatic rings, and the aromatic compound (B) has one or more aromatic rings and electron-withdrawing groups are bonded to the aromatic rings. [2] The organic crystal according to [1], wherein the aromatic compound (A) is at least one aromatic compound selected from the group consisting of aromatic compounds represented by the following formulas A1, A2, and A3, and the aromatic compound (B) is at least one aromatic compound selected from the group consisting of aromatic compounds represented by the following formulas B1, B2, and B3.

[0007] In the above formula A1, R １ ~R ６ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the following formula A1-1. However, R １ ~R ６ One of them is a monovalent aromatic group.

[0008] In the above formula A1-1, * is a coupling, and R １０１ ~R １０５ Each of them independently of the R １ ~R ６ It is the same as above. However, R １０１ ~R １０５ At least one of them is not a hydrogen atom.

[0009] In the formula A2, Ar １ Ar ２ , and Ar ３ These are aromatic rings that are independently fused with a benzene ring. １ Ar ２ , and Ar ３ The number of aromatic rings in each of the above is independently 1 to 6. １１ Ar１ It is a monovalent group bonded to the aforementioned aromatic ring, R １２ Ar ２ It is a monovalent group bonded to the aforementioned aromatic ring, R １３ Ar ３ It is a monovalent group bonded to the aforementioned aromatic ring. １１ , R １２ , and R １３ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the following formula A2-1. １１ If there are multiple R １１ They may be the same or different. １２ If there are multiple R １２ They may be the same or different. １３ If there are multiple R １３ They may be the same or different.

[0010] In the above formula A2-1, * is a coupling, and R １０６ ~R １１０ Each of them independently of the R １１ , R １２ , and R １３ It is the same as above. However, R １０６ ~R １１０ At least one of them is not a hydrogen atom.

[0011] In the above formula A3, Ar ４ Ar is an aromatic ring fused with a benzene ring. ４ The number of aromatic rings in R is one or more. １４ Ar ４ It is a monovalent group bonded to the aforementioned aromatic ring. １４ ~R １８ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having a substituent represented by the following formula A3-1. １４ If there are multiple R １４ They may be the same or different. １４ If there are multiple R１４ may form a ring structure.

[0012] In the formula A3-1, * is a bond, and R １１１ ~R １１５ are each independently the same as the above R １４ ~R １８ However, at least one of R １１１ ~R １１５ is not a hydrogen atom.

[0013] In the formula B1, R ７ ~R １２ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, a monovalent aromatic group having no substituent, or a phenyl group having a substituent represented by the following formula B1-1. However, when not including a phenyl group having a substituent represented by the formula B1-1, any one of R ７ ~R １２ is a monovalent electron-withdrawing group.

[0014] In the formula B1-1, * is a bond, and R １２１ ~R １２５ are each independently the same as the above R ７ ~R １２ However, at least one of R １２１ ~R １２５ is not a hydrogen atom. When any one of the above R ７ ~R １２ is not a monovalent electron-withdrawing group, at least one of R １２１ ~R １２５ is a monovalent electron-withdrawing group.

[0015] In the formula B2, Ar ５ , Ar ６ and Ar ７ are each independently an aromatic ring condensed with a benzene ring. The number of the above aromatic rings of Ar ５ , Ar ６ and Ar ７ is each independently 1 to 6. R ２１ is Ar ５is a monovalent group bonded to the aromatic ring, and R ２２ is a monovalent group bonded to the aromatic ring of Ar ６ is a monovalent group bonded to the aromatic ring, and R ２３ is a monovalent group bonded to the aromatic ring of Ar ７ is a monovalent group bonded to the aromatic ring of Ar. R ２１ , R ２２ , and R ２３ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, a monovalent aromatic group having no substituent, or a phenyl group having a substituent represented by the following formula B2-1. However, when not including the phenyl group having the substituent represented by the formula B2-1, any one of R ２１ to R ２３ is a monovalent electron-withdrawing group. When there are a plurality of R ２１ , the plurality of R ２１ may be the same or different. When there are a plurality of R ２２ , the plurality of R ２２ may be the same or different. When there are a plurality of R ２３ , the plurality of R ２３ may be the same or different.

[0016] In the formula B2-1, * is a bond, and R １２６ to R １３０ are each independently the same as the above R ２１ , R ２２ , and R ２３ . However, at least one of R １２６ to R １３０ is not a hydrogen atom. When any one of the above R ２１ to R ２３ is not a monovalent electron-withdrawing group, at least one of R １２６ to R １３０ is a monovalent electron-withdrawing group.

[0017] In the formula B3, Ar ８ is an aromatic ring condensed with a benzene ring. The number of the aromatic rings of Ar ８ is 1 or more. R ２４ is a monovalent group bonded to the aromatic ring of Ar ８ . R ２４ to R２８ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, an unsubstituted monovalent aromatic group, or a phenyl group having a substituent represented by the following formula B3-1. However, if the phenyl group having a substituent represented by the above formula B3-1 is not included, R ２４ ~R ２８ One of these is a monovalent electron-withdrawing group. ２４ If there are multiple R ２４ They may be the same or different. ２４ If there are multiple R ２４ They may form a ring structure.

[0018] In the above formula B3-1, * is a coupling, and R １３１ ~R １３５ Each of them independently of the R ２４ ~R ２８ It is the same as above. However, R １３１ ~R １３５ At least one of them is not a hydrogen atom. ２４ ~R ２８ If any one of them is not a monovalent electron-withdrawing group, R １３１ ~R １３５ At least one of them is a monovalent electron-withdrawing group. [3] The organic crystal according to [1] or [2], which is a uniaxial crystal. [4] The organic crystal according to any one of [1] to [3], which has a refractive index of 1.8 or more. [5] The organic crystal according to any one of [1] to [4], which has an internal transmittance of 80% or more for light with a wavelength of 450 nm at a thickness of 10 mm. [6] A light guide plate containing the organic crystal according to any one of [1] to [5]. [7] An eyepiece equipped with the light guide plate according to [6].

[0019] According to the present invention, it is possible to provide an organic crystal with a higher refractive index, a light guide plate containing the organic crystal, and an eyepiece equipped with the light guide plate.

[0020] The meanings and definitions of terms used in this invention are as follows: An aromatic compound means a compound having an aromatic ring. An aromatic ring means a ring that satisfies Hückel's rule. The number of aromatic rings is counted as one closed ring. For example, naphthalene is a compound having two aromatic rings. Aromatic rings also include aromatic rings that contain heteroatoms in their ring structure. Examples of aromatic rings that contain heteroatoms in their ring structure include aromatic rings containing nitrogen atoms in their ring structure, such as pyridine, pyridazine, pyrimidine, pyrazine, pyrrole, pyrazole, and imidazole; aromatic rings containing oxygen atoms in their ring structure, such as furan; aromatic rings containing sulfur atoms in their ring structure, such as thiophene; aromatic rings containing nitrogen and sulfur atoms in their ring structure, such as thiazole; and aromatic rings containing nitrogen and oxygen atoms in their ring structure, such as oxazole. A monovalent aromatic group means a monovalent group obtained by removing one hydrogen atom from an aromatic ring. An electron-withdrawing group means a functional group that has the property of attracting electrons. Examples of electron-withdrawing groups include halogen atoms, nitro groups, carbonyl groups, cyano groups, sulfo groups, and trifluoromethyl groups.

[0021] Uniaxiality means that for any three orthogonal axes of an organic crystal (e.g., x, y, and z axes), the refractive indices of two axes (e.g., x and y axes) are equivalent, while the refractive index of the remaining axis (e.g., z axis) is different from that of the other two axes. For example, if the ratio of the refractive index of the x axis to the refractive index of the y axis is between 0.9 and 1.1, and the ratio of (average of the refractive indices of the x axis and y axis) to the refractive index of the z axis is 1.1 or greater, then it can be determined to be a uniaxial crystal. The refractive index refers to the refractive index at the helium d-line (wavelength: 587.6 nm). The refractive index can be measured using the V-block method. The internal transmittance of an organic crystal with a thickness of 10 mm for light at a wavelength of 450 nm can be determined from the measured external transmittance of two types of organic crystals with different thicknesses and from the following formula f1. Note that external transmittance refers to transmittance including surface reflection loss.

[0022] In the above formula f1, X is the internal transmittance of an organic crystal with a thickness of 10 mm for light with a wavelength of 450 nm, and T1 and T2 are the external transmittances for light with a wavelength of 450 nm. The thickness of the sample at the time of T1 measurement is smaller than the thickness of the sample at the time of T2 measurement. Δd is the difference in sample thickness. The external transmittance for light with a wavelength of 450 nm can be measured using a spectrophotometer (for example, Hitachi High-Technologies Corporation: U-4100). The "~" indicating a numerical range means that the values ​​written before and after it are included as the lower and upper limits, respectively. C1-C6 alkyl groups containing an etheric oxygen atom refer to a monovalent group in which an etheric oxygen atom is inserted into at least one carbon chain of a C1-C6 alkyl group.

[0023] ≪Organic Crystals≫ The organic crystals of this embodiment are cocrystals (AB) of one or more aromatic compounds (A) and one or more aromatic compounds (B), cocrystals (BB) of two or more of the above aromatic compounds (B), or single crystals (B) of one of the above aromatic compounds (B). Aromatic compound (A) has two or more aromatic rings, and no electron-withdrawing groups are bonded to the aromatic rings. Aromatic compound (B) has one or more aromatic rings, and electron-withdrawing groups are bonded to the above aromatic rings.

[0024] <Aromatic Compound (A)> Aromatic compound (A) has two or more aromatic rings, and no electron-withdrawing groups are bonded to the aromatic rings. Therefore, the aromatic rings of aromatic compound (A) have electron-rich π electrons. As aromatic compound (A), at least one aromatic compound selected from the group consisting of aromatic compounds represented by the following formulas A1, A2, and A3 is preferred.

[0025] In the above formula A1, R １ ~R ６ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the following formula A1-1. However, R １ ~R ６ One of them is a monovalent aromatic group.

[0026] In the above formula A1-1, * is a coupling, and R １０１ ~R １０５ Each of these independently corresponds to the above R １ ~R ６ It is the same as above. However, R １０１ ~R １０５ At least one of them is not a hydrogen atom.

[0027] The aromatic compound represented by the above formula A1 is R １ , R ３ , and R ５ Each of these is independently a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the above formula A1-1, and R ２ , R ４ , and R ６ Aromatic compounds in which each of the C1-C6 alkyl groups may independently contain a hydrogen atom and an etheric oxygen atom are preferred. Examples of such aromatic compounds include those represented by the following formula A1-2.

[0028] In the above formula A1-2, R １ａ ~R １５ａ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the above formula A1-1, and R １６ａ ~R １８ａ These are alkyl groups having 1 to 6 carbon atoms, each of which may independently contain a hydrogen atom or an etheric oxygen atom. １ａ ~R １５ａ R preferably consists of a C1-C6 alkyl group, which may each independently contain a hydrogen atom and an etheric oxygen atom, with a hydrogen atom being more preferred. １６ａ ~R １８ａ A hydrogen atom is preferred.

[0029] In the above formula A2, Ar １ Ar ２ , and Ar ３ These are aromatic rings that are independently fused with a benzene ring. １ Ar ２ , and Ar ３The number of aromatic rings in each of the above is 1 to 6, independently of each other. １１ Ar １ It is a monovalent group bonded to the above aromatic ring, R １２ Ar ２ It is a monovalent group bonded to the above aromatic ring, R １３ Ar ３ It is a monovalent group bonded to the above aromatic ring. １１ , R １２ , and R １３ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the following formula A2-1. １１ If there are multiple R １１ They may be the same or different. １２ If there are multiple R １２ They may be the same or different. １３ If there are multiple R １３ They may be the same or different. １１ , R １２ , and R １３ Preferably, each of these is an independent hydrogen atom and a monovalent aromatic group without substituents.

[0030] In the above formula A2-1, * is a coupling, and R １０６ ~R １１０ Each of these independently corresponds to the above R １１ , R １２ , and R １３ It is the same as above. However, R １０６ ~R １１０ At least one of them is not a hydrogen atom.

[0031] Ar １ Ar ２ , and Ar ３ The number of aromatic rings in the above-mentioned compound is preferably 1 to 5, and more preferably 1 to 3. １ Ar ２ , and Ar ３ Benzene is preferred as the above aromatic ring. Examples of such aromatic compounds include those represented by the following formula A2-2.

[0032] In the above formula A2-2, R １９ａ ~R ３６ａ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the above formula A2-1. Each of n1 to n3 is independently an integer from 0 to 5.

[0033] R １９ａ ~R ３６ａ Each of these is preferably a C1-C6 alkyl group which may contain a hydrogen atom or an etheric oxygen atom, or a monovalent aromatic group which has no substituents, more preferably a C1-C6 alkyl group which may contain a hydrogen atom or an etheric oxygen atom, and even more preferably a hydrogen atom. Each of n1-n3 is preferably 1-5, and more preferably 1-3. It is preferable that n1-n3 are the same.

[0034] In the above formula A3, Ar ４ Ar is an aromatic ring fused with a benzene ring. ４ The number of aromatic rings in the above is one or more. １４ Ar ４ It is a monovalent group bonded to the above aromatic ring. １４ ~R １８ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having a substituent represented by the following formula A3-1. １４ If there are multiple R １４ They may be the same or different. １４ If there are multiple R １４ They may form a ring structure.

[0035] In the above formula A3-1, * is a coupling, and R １１１ ~R １１５ Each of these independently corresponds to the above R １４ ~R １８ It is the same as above. However, R １１１ ~R １１５ At least one of them is not a hydrogen atom.

[0036] Ar ４ The number of aromatic rings is preferably 1 to 5, and more preferably 1 to 3. ４ Benzene is preferred as the above aromatic ring. Examples of such aromatic compounds include those represented by the following formula A3-2.

[0037] In the above formula A3-2, R ３７ａ ~R ４８ａ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the above formula A3-1. ３７ａ ~R ４８ａ At least two of these elements may form a ring structure. The ring structure may or may not be an aromatic ring. Each of n4 to n6 is independently a non-negative integer, and n4 + n5 + n6 is a non-negative integer of 1 or more. Furthermore, from the viewpoint of suppressing the absorption of visible light, it is preferable that n4 + n5 + n6 is 5 or less.

[0038] R ３７ａ ~R ４８ａ Each of these is preferably a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, or an unsubstituted monovalent aromatic group, more preferably a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, and even more preferably a hydrogen atom. n4 is preferably 1-5, more preferably 1-3. n5 is preferably 0-5, more preferably 0-3. n6 is preferably 0-5, more preferably 0-3. It is preferable that n4-n6 are the same. n4+n5+n6 is preferably 1-10, more preferably 1-5, and even more preferably 2-5.

[0039] <Aromatic Compound (B)> Aromatic compound (B) has one or more aromatic rings, and an electron-withdrawing group is bonded to the aromatic rings. Therefore, the aromatic rings of aromatic compound (B) have electron-deficient π electrons. As aromatic compound (B), at least one aromatic compound selected from the group consisting of aromatic compounds represented by the following formulas B1, B2, and B3 is preferred.

[0040] In the above formula B1, R ７ ~R １２ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, an unsubstituted monovalent aromatic group, or a phenyl group having a substituent represented by the following formula B1-1. However, if a phenyl group having a substituent represented by formula B1-1 is not included, R ７ ~R １２ One of these is a monovalent electron-withdrawing group. A halogen atom is preferred as the monovalent electron-withdrawing group, and a fluorine atom is more preferred.

[0041] In the above formula B1-1, * is a coupling, and R １２１ ~R １２５ Each of these independently corresponds to the above R ７ ~R １２ It is the same as above. However, R １２１ ~R １２５ At least one of them is not a hydrogen atom. ７ ~R １２ If any one of them is not a monovalent electron-withdrawing group, R １２１ ~R １２５ At least one of them is a monovalent electron-withdrawing group.

[0042] In one embodiment, R ７ ~R １２ Preferably, all of them are halogen atoms, R ７ ~R １２ It is more preferable that all of them are fluorine atoms.

[0043] The aromatic compound represented by the above formula B1 is R ７ , R ９ , and R １１ Each of these is independently a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the above formula B1-1, and R ８ , R １０ , and R １２Aromatic compounds are preferred in which each of the following groups independently contains a hydrogen atom, an etheric oxygen atom, a C1-C6 alkyl group, a monovalent electron-withdrawing group, a monovalent aromatic group without substituents, or a phenyl group having substituents represented by the above formula B1-1. Examples of such aromatic compounds include those represented by the following formula B1-2.

[0044] In the above formula B1-2, R １ｂ ~R １８ｂ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, an unsubstituted monovalent aromatic group, or a phenyl group having a substituent represented by the above formula B1-1. However, R １ｂ ~R １８ｂ One of these is a monovalent electron-withdrawing group. １ｂ ~R １５ｂ Each of these is preferably a monovalent electron-withdrawing group or a phenyl group having a substituent represented by the above formula B1-1, more preferably a halogen atom, and even more preferably a fluorine atom. １６ｂ ~R １８ｂ Each of these is preferably a monovalent electron-withdrawing group, more preferably a halogen atom, and even more preferably a fluorine atom.

[0045] In the above formula B2, Ar ５ Ar ６ , and Ar ７ These are aromatic rings that are independently fused with a benzene ring. ５ Ar ６ , and Ar ７ The number of aromatic rings in each of the above is 1 to 6, independently of each other. ２１ Ar ５ It is a monovalent group bonded to the above aromatic ring, R ２２ Ar ６ It is a monovalent group bonded to the above aromatic ring, R ２３ Ar ７ It is a monovalent group bonded to the above aromatic ring. ２１ , R ２２ , and R ２３Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, an unsubstituted monovalent aromatic group, or a phenyl group having a substituent represented by the following formula B2-1. However, if a phenyl group having a substituent represented by formula B2-1 is not included, R ２１ ~R ２３ One of these is a monovalent electron-withdrawing group. ２１ If there are multiple R ２１ They may be the same or different. ２２ If there are multiple R ２２ They may be the same or different. ２３ If there are multiple R ２３ These may be the same or different. A halogen atom is preferred as the monovalent electron-withdrawing group, and a fluorine atom is more preferred.

[0046] In the above formula B2-1, * is a coupling, and R １２６ ~R １３０ Each of these independently corresponds to the above R ２１ , R ２２ , and R ２３ It is the same as above. However, R １２６ ~R １３０ At least one of them is not a hydrogen atom. ２１ ~R ２３ If any one of them is not a monovalent electron-withdrawing group, R １２６ ~R １３０ At least one of them is a monovalent electron-withdrawing group.

[0047] Ar ５ Ar ６ , and Ar ７ The number of aromatic rings in the above-mentioned compound is preferably 1 to 5, and more preferably 1 to 3. ５ Ar ６ , and Ar ７ Benzene is preferred as the above aromatic ring. Examples of such aromatic compounds include those represented by the following formula B2-2.

[0048] In the above formula B2-2, R １９ｂ ~R ３６ｂEach of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, an unsubstituted monovalent aromatic group, or a phenyl group having a substituent represented by the above formula B2-1. However, R １９ｂ ~R ３６ｂ One of these is a monovalent electron-withdrawing group. n7 to n9 are each independent integers from 0 to 5. However, R １９ｂ ~R ３６ｂ One of these groups is a monovalent electron-withdrawing group.

[0049] R １９ｂ ~R ３６ｂ Each of these is preferably a monovalent electron-withdrawing group or a phenyl group having a substituent represented by the above formula B2-1, more preferably a halogen atom, and even more preferably a fluorine atom. Each of n7 to n9 is preferably 1 to 5, and more preferably 1 to 3. It is preferable that n7 to n9 are the same.

[0050] In the above formula B3, Ar ８ Ar is an aromatic ring fused with a benzene ring. ８ The number of aromatic rings in the above is one or more. ２４ Ar ８ It is a monovalent group bonded to the above aromatic ring. ２４ ~R ２８ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, an unsubstituted monovalent aromatic group, or a phenyl group having a substituent represented by formula B3-1 below. However, if a phenyl group having a substituent represented by formula B3-1 is not included, R ２４ ~R ２８ One of these is a monovalent electron-withdrawing group. ２４ If there are multiple R ２４ They may be the same or different. ２４ If there are multiple R ２４ The ring structure may be formed. A halogen atom is preferred as the monovalent electron-withdrawing group, and a fluorine atom is more preferred.

[0051] In the above formula B3-1, * is a coupling, and R１３１ ~R １３５ Each of these independently corresponds to the above R ２４ ~R ２８ It is the same as above. However, R １３１ ~R １３５ At least one of them is not a hydrogen atom. ２４ ~R ２８ If any one of them is not a monovalent electron-withdrawing group, R １３１ ~R １３５ At least one of them is a monovalent electron-withdrawing group.

[0052] Ar ８ The number of aromatic rings is preferably 1 to 5, and more preferably 1 to 3. ８ Benzene is preferred as the above aromatic ring. Examples of such aromatic compounds include those represented by the following formula B3-2.

[0053] In the above formula B3-2, R ３７ｂ ~R ４８ｂ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, a monovalent aromatic group which has no substituents, or a phenyl group which has a substituent represented by the above formula B3-1. ３７ｂ ~R ４８ｂ At least two of these may form a ring structure. The ring structure may or may not be an aromatic ring. n10 to n12 are each independent integers of 0 or greater, and n10 + n11 + n12 is an integer of 1 or greater. However, R ３７ｂ ~R ４８ｂ One of these groups is a monovalent electron-withdrawing group. Furthermore, from the viewpoint of suppressing absorption by visible light, it is preferable that n10 + n11 + n12 is 5 or less.

[0054] R ３７ｂ ~R ４８ｂEach of the following is preferably a monovalent electron-withdrawing group or a phenyl group having a substituent represented by the above formula B3-1, more preferably a halogen atom, and even more preferably a fluorine atom. Each of the following is preferably 1 to 5 for n10, and more preferably 1 to 3 for n11. Each of the following is preferably 0 to 5 for n11, and more preferably 0 to 3 for n12. It is preferable that n10 to n12 are the same. n10 + n11 + n12 is preferably 1 to 10, more preferably 1 to 5, and even more preferably 2 to 5.

[0055] <Cocrystal (AB)> The aromatic compounds (A) that form the cocrystal (AB) are preferably three or fewer, more preferably two or fewer, and even more preferably one. The aromatic compounds (B) that form the cocrystal (AB) are preferably three or fewer, more preferably two or fewer, and even more preferably one.

[0056] The ratio of the number of aromatic rings in the structure of aromatic compound (B) × the number of moles of aromatic compound (B) to the number of aromatic rings in the structure of aromatic compound (A) × the number of moles of aromatic compound (A) forming the cocrystal (AB) is preferably 0.3 to 3.0, more preferably 0.5 to 2.0, and even more preferably 0.8 to 1.2. When the above ratio is within the above range, aromatic compound (A) and aromatic compound (B) are tightly packed, and a high refractive index is likely to be achieved.

[0057] The ratio of the number of electron-withdrawing groups in aromatic compound (B) to the number of hydrogen atoms in aromatic compound (A) forming the cocrystal (AB) is preferably 0.3 to 3.0, more preferably 0.5 to 2.0, and even more preferably 0.8 to 1.2. When the above ratio is within the above range, aromatic compound (A) and aromatic compound (B) are tightly packed, and a high refractive index is likely to be achieved.

[0058] The ratio of moles of aromatic compound (B) to moles of aromatic compound (A) forming the cocrystal (AB) is preferably 0.3 to 3.0, more preferably 0.5 to 2.0, and even more preferably 0.8 to 1.2. When the above ratio is within the above range, aromatic compound (A) and aromatic compound (B) are tightly packed, and a high refractive index is likely to be achieved.

[0059] <Cocrystal (BB)> The aromatic compounds (B) that form the cocrystal (BB) are preferably four or fewer, more preferably three or fewer, and even more preferably two.

[0060] The ratio of electron-withdrawing groups to hydrogen atoms in the aromatic compound (B) forming the cocrystal (BB) is preferably 0.3 to 3.0, more preferably 0.5 to 2.0, and even more preferably 0.8 to 1.2. When the ratio is within the above range, the aromatic compound (B) is densely packed, and a high refractive index is likely to be achieved. It is preferable that the above ratio is within the above range for all aromatic compounds (B) forming the cocrystal (BB).

[0061] <Single Crystal (B)> The ratio of electron-withdrawing groups to the number of hydrogen atoms in the aromatic compound (B) forming the single crystal (B) is preferably 0.3 to 3.0, more preferably 0.5 to 2.0, and even more preferably 0.8 to 1.2. When the above ratio is within the above range, the aromatic compound (B) is densely packed, and a high refractive index is likely to be achieved.

[0062] The existence of a crystalline structure in cocrystals (AB), cocrystals (BB), and single crystals (B) can be confirmed by X-ray diffraction measurement.

[0063] <Characteristics of Organic Crystals> Organic crystals are preferably uniaxial crystals. The refractive index of the organic crystal is preferably 1.8 or higher, more preferably 1.9 or higher, and even more preferably 2.0 or higher. There is no particular upper limit to the refractive index, but it may be 4.0 or lower, or 3.0 or lower. The range is preferably 1.8 to 4.0, more preferably 1.9 to 4.0, even more preferably 1.9 to 3.0, and particularly preferably 2.0 to 3.0. Note that the refractive index of the organic crystal refers to the refractive index at the axis with the highest refractive index. In the organic crystal of this embodiment, aromatic compound (A) and aromatic compound (B) are densely packed, making it easy to achieve a high refractive index.

[0064] The internal transmittance of an organic crystal with a thickness of 10 mm for light with a wavelength of 450 nm is preferably 80% or higher, more preferably 85% or higher, and even more preferably 90% or higher. The upper limit of the internal transmittance is not particularly limited, but it may be 98% or lower, or 95% or lower. The range is preferably 80 to 98%, more preferably 85 to 95%, and even more preferably 90 to 95%. If the internal transmittance is above the lower limit of the above, high transmittance for visible light can be achieved.

[0065] The shape of the organic crystal is not particularly limited, but for example, it may be plate-shaped. When the organic crystal is plate-shaped, the thickness is preferably 0.5 mm or more, more preferably 1.0 mm or more, even more preferably 5.0 mm or more, preferably 100 mm or less, more preferably 80 mm or less, and even more preferably 50 mm or less. The range is preferably 0.5 to 100 mm, more preferably 1.0 to 80 mm, and even more preferably 5.0 to 50 mm. The thickness of the organic crystal can be measured with a micrometer.

[0066] <Methods for Manufacturing Organic Crystals> Organic crystals can be manufactured as follows: In the case of cocrystals (AB), aromatic compounds (A) and (B) can be dissolved in a solvent and the solvent can be evaporated. Alternatively, they may be manufactured by cooling the solution. In the case of cocrystals (BB), aromatic compounds (B) can be dissolved in a solvent and the solvent can be evaporated. Alternatively, they may be manufactured by cooling the solution. In the case of single crystals (B), aromatic compounds (B) can be dissolved in a solvent and the solvent can be evaporated. Alternatively, they may be manufactured by cooling the solution. Aromatic compounds (A) and (B) can be manufactured by conventionally known methods.

[0067] The solvents used in the production of organic crystals are not particularly limited, but include hydrocarbon solvents such as heptane, hexane, pentane, octane, nonane, decane, acetone, 2-butanone, acetonitrile, ethyl acetate, tert-butyl methyl ether, dimethyl carbonate, tetrahydrofuran, cyclohexane, cyclopentane, and cyclohexanone; alcohol solvents such as methanol, ethanol, propanol, butanol, phenol, cresol, ethylene glycol, and 2-methoxyethanol; chlorine-containing solvents such as dichloromethane, chloroform, 1,2-dichloroethylene, trichloroethylene, and perchloroethylene; aromatic solvents such as toluene, xylene, mesitylene, and anisole; methyl nonafluorobutyl ether, ethyl nonafluorobutyl ether, methyl tridecafluorohexyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoroisopropanol, and 1,2,2,3 ,3,4,4-heptafluorocyclopentane, 1H,1H-pentafluoropropanol, 1H,1H-heptafluorobutanol, 2-perfluorobutylethanol, 4,4,4-trifluorobutanol, 1H,1H,3H-tetrafluoropropanol, 1H,1H,5H-octafluoropropanol, 1H,1H,7H-dodecafluoroheptanol, 2,2,3,3,3-pentafluoropropyl-1,1,2,2-tetrafluoroethyl ether, 1,1,2,2-tetrafluoroethyl ether Examples of fluorinated solvents include ethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, hexafluoroisopropyl methyl ether, 1,1,3,3,3-pentafluoro-2-trifluoromethylpropyl methyl ether, 1,1,2,3,3,3-hexafluoropropyl methyl ether, 1,1,2,3,3,3-hexafluoropropyl ethyl ether, and 2,2,3,4,4,4-hexafluorobutyldifluoromethyl ether. These solvents may be used individually or in combination of two or more. From the viewpoint of solubility, chlorine-containing solvents, aromatic solvents, and hydrocarbon solvents are preferred.

[0068] <Applications of Organic Crystals> Applications of organic crystals include optical components such as light guide plates, optical lenses, and displays. The light guide plate may consist solely of organic crystals, or it may have a surface treatment agent on its surface. The surface treatment agent is not particularly limited as long as it does not significantly reduce the internal transmittance of the light guide plate to light at a wavelength of 450 nm, but examples include metal oxide thin films, thin films with anti-reflective properties, and surface modification coating materials such as silica and titania. The organic crystals of this embodiment have a high refractive index and high transmittance, making them suitable for use as light guide plates.

[0069] Light guide plates containing organic crystals are useful in various optical elements, but are preferably used in eyepieces. In particular, they are suitable for use in (1) light guides, filters, and lenses used in wearable devices such as projector-equipped glasses, spectacle-type and goggle-type displays, virtual reality and augmented reality display devices, and virtual image display devices, and (2) lenses and cover glass used in automotive cameras and robot vision sensors. They are suitable for use even in applications exposed to harsh environments, such as automotive cameras. They are also suitable for use in applications such as glass substrates for organic EL, substrates for wafer-level lens arrays, substrates for lens units, lens formation substrates by etching methods, and optical waveguides. The organic crystal of this embodiment described above has a high refractive index and high transmittance, making it suitable for wearable devices, automotive applications, and robot-mounted applications. Furthermore, SiO is present on the main surface of the organic crystal. ２ Low refractive index films such as TiO ２ Optical components having an anti-reflective coating formed from a dielectric multilayer film consisting of 4 to 10 layers, which are alternately laminated with high refractive index films, are also suitable for wearable devices, automotive applications, and robotic applications.

Claims

1. An organic crystal which is a cocrystal (AB) of one or more aromatic compounds (A) and one or more aromatic compounds (B), a cocrystal (BB) of two or more of the aforementioned aromatic compounds (B), or a single crystal (B) of one of the aforementioned aromatic compounds (B), wherein the aromatic compound (A) has two or more aromatic rings and no electron-withdrawing groups are bonded to the aromatic rings, and the aromatic compound (B) has one or more aromatic rings and electron-withdrawing groups are bonded to the aromatic rings.

2. The aromatic compound (A) is at least one aromatic compound selected from the group consisting of aromatic compounds represented by the following formula A1, formula A2, and formula A3, and the aromatic compound (B) is at least one aromatic compound selected from the group consisting of aromatic compounds represented by the following formula B1, formula B2, and formula B3. The organic crystal according to claim 1. In the formula A1, R １ to R ６ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may contain an etheric oxygen atom, a monovalent aromatic group having no substituent, or a phenyl group having a substituent represented by the following formula A1-1. However, any one of R １ to R ６ is a monovalent aromatic group. In the formula A1-1, * is a bond, and R １０１ to R １０５ are each independently the same as R １ to R ６ . However, at least one of R １０１ to R １０５ is not a hydrogen atom. In the formula A2, Ar １ , Ar ２ , and Ar ３ are each independently an aromatic ring condensed with a benzene ring. The number of the aromatic rings of Ar １ , Ar ２ , and Ar ３ is each independently 1 to 6. R １１ is a monovalent group bonded to the aromatic ring of Ar １ , R １２ is a monovalent group bonded to the aromatic ring of Ar ２ , and R １３ is a monovalent group bonded to the aromatic ring of Ar ３ . R １１ , R １２ , and R １３ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may contain an etheric oxygen atom, a monovalent aromatic group having no substituent, or a phenyl group having a substituent represented by the following formula A2-1. R １１ If there are multiple R １１ They may be the same or different. １２ If there are multiple R １２ They may be the same or different. １３ If there are multiple R １３ They may be the same or different. In the above formula A2-1, * is a coupling, and R １０６ ~R １１０ Each of them independently of the R １１ , R １２ , and R １３ It is the same as above. However, R １０６ ~R １１０ At least one of them is not a hydrogen atom. In the above formula A3, Ar ４ Ar is an aromatic ring fused with a benzene ring. ４ The number of aromatic rings in R is one or more. １４ Ar ４ It is a monovalent group bonded to the aforementioned aromatic ring. １４ ~R １８ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent aromatic group without substituents, or a phenyl group having a substituent represented by the following formula A3-1. １４ If there are multiple R １４ They may be the same or different. １４ If there are multiple R １４ They may form a ring structure. In the above formula A3-1, * is a coupling, and R １１１ ~R １１５ Each of them independently of the R １４ ~R １８ It is the same as above. However, R １１１ ~R １１５ At least one of them is not a hydrogen atom. In the above formula B1, R ７ ~R １２ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, a monovalent aromatic group which has no substituents, or a phenyl group which has a substituent represented by the following formula B1-1. However, if the phenyl group which has a substituent represented by the above formula B1-1 is not included, R ７ ~R １２ One of these groups is a monovalent electron-withdrawing group. In the above formula B1-1, * is a coupling, and R １２１ ~R １２５ Each of them independently of the R ７ ~R １２ It is the same as above. However, R １２１ ~R １２５ At least one of them is not a hydrogen atom. ７ ~R １２ If any one of them is not a monovalent electron-withdrawing group, R １２１ ~R １２５ At least one of them is a monovalent electron-withdrawing group. In the above formula B2, Ar ５ Ar ６ , and Ar ７ These are aromatic rings that are independently fused with a benzene ring. ５ Ar ６ , and Ar ７ The number of aromatic rings in each of the above is independently 1 to 6. ２１ Ar ５ It is a monovalent group bonded to the aforementioned aromatic ring, R ２２ Ar ６ It is a monovalent group bonded to the aforementioned aromatic ring, R ２３ Ar ７ It is a monovalent group bonded to the aforementioned aromatic ring. ２１ , R ２２ , and R ２３ Each of these is independently a hydrogen atom, a C1-C6 alkyl group which may contain an etheric oxygen atom, a monovalent electron-withdrawing group, an unsubstituted monovalent aromatic group, or a phenyl group having a substituent represented by the following formula B2-1. However, if the phenyl group having a substituent represented by the above formula B2-1 is not included, R ２１ ~R ２３ Any one of them is a monovalent electron-withdrawing group. R ２１ When there are a plurality of R's, the plurality of R's ２１ may be the same or different. R ２２ When there are a plurality of R's, the plurality of R's ２２ may be the same or different. R ２３ When there are a plurality of R's, the plurality of R's ２３ may be the same or different. In the formula B2-1, * is a bond, and R １２６ to R １３０ are each independently the same as the above-mentioned R ２１ , R ２２ , and R ２３ . However, at least one of R １２６ to R １３０ is not a hydrogen atom. When any one of the above-mentioned R ２１ to R ２３ is not a monovalent electron-withdrawing group, at least one of R １２６ to R １３０ is a monovalent electron-withdrawing group. In the formula B3, Ar ８ is an aromatic ring condensed with a benzene ring. The number of the aromatic rings of Ar ８ is one or more. R ２４ is a monovalent group bonded to the aromatic ring of Ar ８ . R ２４ to R ２８ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may contain an ether oxygen atom, a monovalent electron-withdrawing group, a monovalent aromatic group having no substituent, or a phenyl group having a substituent represented by the following formula B3-1. However, when not including a phenyl group having a substituent represented by the formula B3-1, any one of R ２４ to R ２８ is a monovalent electron-withdrawing group. When there are a plurality of R's, the plurality of R's ２４ may be the same or different. When there are a plurality of R's, at least two of R ２４ may form a ring structure. ２４ In the formula B3-1, * is a bond, and R ２４ to R １３１ are each independently the same as the above-mentioned R １５ to R １５ ​ ２４ ~R ２８ It is the same as above. However, R １３１ ~R １３５ At least one of them is not a hydrogen atom. ２４ ~R ２８ If any one of them is not a monovalent electron-withdrawing group, R １３１ ~R １３５ At least one of them is a monovalent electron-withdrawing group.

3. The organic crystal according to claim 1, wherein it is a uniaxial crystal.

4. The organic crystal according to claim 1, wherein the refractive index is 1.8 or greater.

5. The organic crystal according to claim 1, wherein the internal transmittance to light with a wavelength of 450 nm at a thickness of 10 mm is 80% or more.

6. A light guide plate containing an organic crystal according to any one of claims 1 to 5.

7. An eyepiece comprising the light guide plate described in claim 6.

Images