Copolymers, nonlinear optical materials and electro-optical components

Abstract

The object of this invention is to provide a copolymer with nonlinear optically active sites capable of forming a crack-free film, a nonlinear optical material comprising the copolymer, and an electro-optical element. The copolymer of this invention is characterized by comprising repeating structural units (A) having adamantyl alkyl groups and repeating structural units (B) having nonlinear optically active sites, as represented by formula (1). (Where R...) 1 W represents a hydrogen atom or a methyl group. 1 Indicates -O-, -S-, or -NH-, L 1 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain single bonds, ether bonds, and / or ester bonds, or *-L. 2 -NHC(=O)O- (* indicates W) 1 (bonding end), L 2 Ad represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds; Ad represents an adamantyl group that may be substituted by an alkyl group with 1 to 5 carbon atoms; R represents a divalent hydrocarbon group that may contain ether bonds and / or ester bonds. 2 The alkoxy group represents 1 to 10 carbon atoms bonded to any carbon atom constituting the adamantyl alkyl group, where n represents an integer from 1 to 15. (1)

Description

Technical Field

[0001] This invention relates to copolymers having nonlinear optically active sites. Background Technology

[0002] In recent years, the development of various optoelectronic components using materials containing fluorescent dyes and nonlinear optical materials has been promoted in fields such as optical information processing and optical communication. Among them, nonlinear optical materials are materials that exhibit polarization responses proportional to the square, cube, or higher-order terms of the magnitude of the photoelectric field, and the application of nonlinear optical materials that produce second-order nonlinear optical effects, namely the first-order electro-optic effect (Pokkers effect), to optical switches, optical modulation, etc., is being considered.

[0003] Previously, lithium niobate and potassium dihydrogen phosphate, as inorganic nonlinear optical materials, have been practically applied and widely used. However, in recent years, compared with these inorganic nonlinear optical materials, organic nonlinear optical materials, which have advantages such as high nonlinear optical performance, low material cost, and high mass production capability, have attracted attention and are undergoing active research and development for practical application.

[0004] Methods for fabricating devices using organic nonlinear optical materials include, for example, methods using single crystals of compounds with nonlinear optical properties (nonlinear optical compounds), vapor deposition, and LB film methods. Other methods include incorporating structures with nonlinear optical properties into the main chain or side chains of polymer compounds, or dispersing nonlinear optical compounds in a polymer matrix. Particularly in polymer systems, films can be formed using casting, impregnation, and spin coating methods, thus offering the advantage of ease of processing.

[0005] For example, Patent Document 1 discloses a nonlinear optically active copolymer comprising, within the same molecule, at least a repeating unit A having a specific structure of adamantyl alkyl and a repeating unit B having a specific structure of a nonlinear optically active site. Furthermore, it describes that this nonlinear optically active copolymer possesses sufficient orientation characteristics and is capable of suppressing orientation relaxation of the nonlinear optical material caused by heat.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2017 / 159815 Summary of the Invention

[0009] In devices using nonlinear optical materials, evaluating absorption loss at the wavelengths in use is crucial. Thicker films formed from nonlinear optical materials allow for more accurate evaluation of absorption loss in wavelength bands with lower absorption compared to thinner films, making them preferable. However, increased film thickness increases the likelihood of crack formation, leading to scattering loss and hindering accurate evaluation of absorption loss. Therefore, films formed using nonlinear optical materials must be thick and crack-free. Furthermore, in the fabrication processes of devices using nonlinear optical materials, film formation is frequently performed not only on flat surfaces but also on various uneven surfaces, increasing the risk of cracking due to stress (strain) caused by these surface irregularities. Therefore, there is a need to develop nonlinear optical materials that are less prone to cracking.

[0010] The nonlinear optically active copolymer described in Patent Document 1 has the problem that the film is prone to cracking during film formation, especially when the film thickness increases.

[0011] The present invention was made in view of the above-mentioned problems, and its object is to provide a copolymer having nonlinear optical active sites capable of forming a crack-free film, a nonlinear optical material comprising the copolymer, and an electro-optical element.

[0012] To address the aforementioned issues, the inventors conducted in-depth research and discovered that by introducing repeating structural units comprising adamantyl groups having alkoxy groups with 1 to 10 carbon atoms into a polymer with nonlinear optically active sites, and then using this polymer to form a film, a crack-free film can be formed even when the film is thick. This invention was achieved through further repeated research based on the above insights.

[0013] That is, the present invention provides an invention in the following manner.

[0014] Item 1. A copolymer comprising:

[0015] The repeating structural unit (A), represented by the following formula (1) and having an adamantyl alkyl group, and

[0016] The repeating structural unit (B) has a nonlinear optically active site.

[0017] (1)

[0018] (where R) 1 W represents a hydrogen atom or a methyl group. 1 Indicates -O-, -S-, or -NH-, L 1 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain single bonds, ether bonds, and / or ester bonds, or *-L. 2-NHC(=O)O- (* indicates W) 1 (bonding end), L 2 Ad represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds; Ad represents an adamantyl group that may be substituted by an alkyl group with 1 to 5 carbon atoms; R represents a divalent hydrocarbon group that may contain ether bonds and / or ester bonds. 2 The alkoxy group represents 1 to 10 carbon atoms bonded to any carbon atom constituting the adamantyl alkyl group, where n represents an integer from 1 to 15.

[0019] Item 2. The copolymer according to Item 1, wherein the repeating structural unit (B) comprises repeating structural unit (B1) represented by the following formula (2-1) and / or repeating structural unit (B2) represented by the following formula (2-2).

[0020] (2-1)

[0021] (2-2)

[0022] (where R) 3 W represents a hydrogen atom or a methyl group. 2 Indicates -O-, -S-, or -NH-, L 3 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, or *-L. 4 -NHC(=O)O- (* indicates W) 2 (bonding end), L 4 "Z" represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, and "Z" represents an atomic group exhibiting nonlinear optical activity.

[0023] Item 3. The copolymer according to item 1 or 2, wherein the content of the repeating structural unit (A) is 5 to 95 mol% and the content of the repeating structural unit (B) is 5 to 95 mol%.

[0024] Item 4. The copolymer according to Item 3, further comprising a repeating structural unit (C) with a structure different from that of the repeating structural unit (A) and the repeating structural unit (B) described above, wherein the content of the repeating structural unit (C) is 90 mol% or less.

[0025] Item 5. A composition comprising any one of items 1 to 4, and a solvent.

[0026] Item 6. A nonlinear optical material comprising any one of items 1 to 4.

[0027] Item 7. A nonlinear optical material comprising the copolymer described in Item 1 and / or a polymer comprising repeating structural units (A) having adamantyl alkyl groups as represented by the following formula (1) and not containing repeating structural units (B) having nonlinear optical active sites, and a nonlinear optical active compound.

[0028] (1)

[0029] (where R) 1 W represents a hydrogen atom or a methyl group. 1 Indicates -O-, -S-, or -NH-, L 1 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain single bonds, ether bonds, and / or ester bonds, or *-L. 2 -NHC(=O)O- (* indicates W) 1 (bonding end), L 2 Ad represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds; Ad represents an adamantyl group that may be substituted by an alkyl group with 1 to 5 carbon atoms; R represents a divalent hydrocarbon group that may contain ether bonds and / or ester bonds. 2 (This refers to an alkoxy group with 1 to 10 carbon atoms bonded to any carbon atom constituting the adamantyl alkyl group, where n represents an integer from 1 to 15.)

[0030] Item 8. An electro-optical element comprising any one of items 1 to 4, or the nonlinear optical material described in item 6 or 7.

[0031] The copolymer of the present invention contains an adamantyl alkyl group having alkoxy groups having 1 to 10 carbon atoms in the aforementioned repeating structural unit (A), enabling the formation of a crack-free film regardless of whether the film is thin or thick. The thick, crack-free film formed using the copolymer with nonlinear optical active sites allows for accurate evaluation of absorption loss at the wavelength in the device containing the film, making it highly preferred. Furthermore, the copolymer of the present invention, capable of forming crack-free films, expands the range of applications in devices using nonlinear optical materials.

[0032] Furthermore, the copolymer of the present invention has the advantage of being easy to produce thick films because it has high solubility in common film-forming solvents and can produce high-concentration film-forming solutions.

[0033] In addition, the copolymer of the present invention has a large electro-optic coefficient (r) and exhibits superior electro-optic effect compared with conventional copolymers with nonlinear optical active sites.

[0034] Because the copolymer of the present invention possesses the aforementioned characteristics, it is suitable as a material for electro-optical components such as optical switches, optical modulators, phase shifters, and terahertz wave generating and detecting elements. Furthermore, various types of optical switches, optical modulators, phase shifters, and terahertz wave generating and detecting elements exist, and in the manufacturing process of these elements, film formation is frequently performed not only on flat surface structures but also on various uneven surface structures. Films on uneven surface structures are more prone to cracking due to the stress (strain) caused by the structure. Therefore, the copolymer of the present invention can expand the application range of the aforementioned electro-optical components. Detailed Implementation

[0035] In this invention, (meth)acrylate refers to acrylate and / or methacrylate, (meth)acrylate group refers to acrylate and / or methacrylate group, (meth)acryloyl group refers to acryloyl and / or methacryloyl group, and (meth)acrylic acid refers to acrylic acid and / or methacrylic acid.

[0036] 1. Copolymer

[0037] The copolymer of the present invention is characterized in that it comprises repeating structural units (A) having adamantyl alkyl groups and repeating structural units (B) having nonlinear optically active sites, as represented by the following formula (1).

[0038] (1)

[0039] (where R) 1 W represents a hydrogen atom or a methyl group. 1 Indicates -O-, -S-, or -NH-, L 1 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain single bonds, ether bonds, and / or ester bonds, or *-L. 2 -NHC(=O)O- (* indicates W) 1 (bonding end), L 2 Ad represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds; Ad represents an adamantyl group that may be substituted by an alkyl group with 1 to 5 carbon atoms; R represents a divalent hydrocarbon group that may contain ether bonds and / or ester bonds. 2 The alkoxy group represents 1 to 10 carbon atoms bonded to any carbon atom constituting the adamantyl alkyl group, where n represents an integer from 1 to 15.

[0040] The copolymers of the present invention can be random copolymers or block copolymers.

[0041] <Repeating structural unit (A)>

[0042] The copolymer of the present invention comprises repeating structural unit (A) having an adamantyl alkyl group, as represented by formula (1) above. The repeating structural unit (A) may comprise one or more types.

[0043] R in equation (1) 1 It can be a hydrogen atom or a methyl group, preferably a methyl group.

[0044] W in equation (1) 1 It can be -O-, -S-, or -NH-, preferably -O-.

[0045] L in equation (1) 1 A single bond, or a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, or *-L 2 -NHC(=O)O-. The "*" above refers to the combination with W. 1 The bonding ends. The above L 2 It is a divalent hydrocarbon group with 1 to 30 carbon atoms, which may contain ether bonds and / or ester bonds. In the above L... 1 and L 2 In this context, the divalent hydrocarbon group having 1 to 30 carbon atoms is not particularly limited and can be any of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. Furthermore, the aliphatic hydrocarbon group can be any of a straight-chain, branched, or cyclic form. Among these, an aliphatic hydrocarbon group is preferred, and an alkylene group having 1 to 6 carbon atoms is more preferred.

[0046] Examples of divalent hydrocarbon groups with 1 to 30 carbon atoms include straight-chain aliphatic hydrocarbon groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, octane-1,8-diyl, decane-1,10-diyl, eicosane-1,20-diyl, and triacontane-1,30-diyl; branched aliphatic hydrocarbon groups such as methyl ethylene, 1-methyltrimethylene, and 2,2-dimethyltrimethylene; and cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and tricyclic [5.2.1.0]. 2,6 Cyclic aliphatic hydrocarbon groups such as decanediyl, adamantanediyl, norbornanediyl, and norbornenediyl; aromatic hydrocarbon groups such as phenylene, toluenediyl, and naphthyl.

[0047] L in equation (1) 1 Single bonds are preferred.

[0048] In formula (1), Ad is an adamantyl alkyl group that can be substituted with an alkyl group having 1 to 5 carbon atoms. There are no particular limitations on the alkyl group having 1 to 5 carbon atoms; it can be any of the following: linear, branched, or cyclic. Examples include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, neopentyl, and cyclopentyl. The aforementioned Ad can have one alkyl group having 1 to 5 carbon atoms, or it can have two or more.

[0049] In formula (1), Ad is preferably an adamantyl alkyl group that is not substituted by an alkyl group having 1 to 5 carbon atoms.

[0050] R in equation (1) 2 It is an alkoxy group having 1 to 10 carbon atoms bonded to any carbon atom constituting the aforementioned adamantyl alkyl group. In formula (1), n ​​is an integer from 1 to 15. From the viewpoint of increasing the glass transition temperature (Tg), the number of carbon atoms in the aforementioned alkoxy group is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. Furthermore, from the viewpoint of ease of manufacture and fully obtaining the effects of the present invention, the aforementioned n is preferably an integer from 1 to 10, more preferably an integer from 1 to 5, even more preferably an integer from 1 to 3, and particularly preferably 1. It should be noted that when n is an integer of 2 or more, the number of carbon atoms in each alkoxy group may be the same or different.

[0051] <Repeating Structural Unit (B)>

[0052] The copolymer of the present invention comprises repeating structural units (B) having nonlinear optically active sites. The repeating structural units (B) may comprise one type or more types.

[0053] The repeating structural unit (B) need only have a nonlinear optically active site; there are no particular restrictions. The aforementioned nonlinear optically active site refers to an atomic group exhibiting nonlinear optical activity. The aforementioned atomic group exhibiting nonlinear optical activity refers to an atomic group derived from an organic nonlinear optical compound. There are no particular restrictions on the organic nonlinear optical compound; known organic nonlinear optical compounds can be cited, such as π-conjugated compounds having an electron-donating group at one end of the π-conjugated chain and an electron-withdrawing group at the other end. Organic nonlinear optical compounds with a high molecular hyperpolarizability β are preferred. Examples of electron-donating groups include dialkylamino groups, and examples of electron-withdrawing groups include cyano, nitro, and fluoroalkyl groups.

[0054] In the copolymer of the present invention, the repeating structural unit (B) having a nonlinear optically active site preferably includes the repeating structural unit (B1) represented by the following formula (2-1) and / or the repeating structural unit (B2) represented by the following formula (2-2).

[0055] (2-1)

[0056] (2-2)

[0057] (where R) 3 W represents a hydrogen atom or a methyl group. 2 Indicates -O-, -S-, or -NH-, L 3 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, or *-L. 4 -NHC(=O)O- (* indicates W)2 (bonding end), L 4 "Z" represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, and "Z" represents an atomic group exhibiting nonlinear optical activity.

[0058] R in equations (2-1) and (2-2) 3 It can be a hydrogen atom or a methyl group, preferably a methyl group.

[0059] W in equations (2-1) and (2-2) 2 It can be -O-, -S-, or -NH-, preferably -O-.

[0060] L in equations (2-1) and (2-2) 3 It is a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, or *-L 4 -NHC(=O)O-. The "*" above refers to the combination with W. 2 The bonding ends. The above L 4 It is a divalent hydrocarbon group with 1 to 30 carbon atoms, which may contain ether bonds and / or ester bonds. In the above L... 3 and L 4 In this context, the divalent hydrocarbon group having 1 to 30 carbon atoms is not particularly limited and can be any of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. Furthermore, as an aliphatic hydrocarbon group, it can be any of a straight-chain, branched, or cyclic form.

[0061] Examples of divalent hydrocarbon groups with 1 to 30 carbon atoms include straight-chain aliphatic hydrocarbon groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, octane-1,8-diyl, decane-1,10-diyl, eicosane-1,20-diyl, and triacontane-1,30-diyl; branched aliphatic hydrocarbon groups such as methyl ethylene, 1-methyltrimethylene, and 2,2-dimethyltrimethylene; and cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and tricyclic [5.2.1.0]. 2,6 Cyclic aliphatic hydrocarbon groups such as decanediyl, adamantanediyl, norbornanediyl, and norbornenediyl; aromatic hydrocarbon groups such as phenylene, toluenediyl, and naphthyl.

[0062] L in equations (2-1) and (2-2) 3 Preferably, it is an aliphatic hydrocarbon group with 1 to 30 carbon atoms, more preferably an alkylene group with 1 to 6 carbon atoms, even more preferably an alkylene group with 1 to 4 carbon atoms, and particularly preferably an alkylene group with 2 to 4 carbon atoms.

[0063] In formulas (2-1) and (2-2), Z represents an atomic group exhibiting nonlinear optical activity. This atomic group is derived from organic nonlinear optical compounds. There are no particular limitations on what constitutes an organic nonlinear optical compound; examples include well-known organic nonlinear optical compounds, such as π-conjugated compounds with an electron-donating group at one end of the π-conjugated chain and an electron-withdrawing group at the other end. Examples of electron-donating groups include dialkylamino groups, and examples of electron-withdrawing groups include cyano, nitro, and fluoroalkyl groups.

[0064] In formulas (2-1) and (2-2), Z is preferably the atomic group represented by formula (3-1) or (3-2) below.

[0065] (3-1) (3-2)

[0066] (where R) 4 Indicates -O- or -NR 5 -, R 5 R represents an alkyl group having 1 to 5 hydrogen atoms or carbon atoms. 6 and R 7 Each of these elements independently represents a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an aryl group with 6 to 10 carbon atoms. The symbol * indicates the bonding site with the remaining structure of the group Z, which exhibits nonlinear optical activity.

[0067] In formulas (2-1) and (2-2), Z is preferably a group of atoms having a functional group derived from a compound represented by formula (4-1) or (4-2), i.e., preferably R from a compound represented by formula (4-1) or (4-2). 8 ~R 20 A group of atoms formed by removing one or two hydrogen atoms from any one of them.

[0068] (4-1)

[0069] (4-2)

[0070] (where R) 4 Indicates -O- or -NR 5 -, R 5 R represents an alkyl group having 1 to 5 hydrogen atoms or carbon atoms. 6 and R 7 Each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a haloalkyl group having 1 to 5 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R 8 and R 9Each of the following independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms that may have substituents, or an aryl group having 6 to 10 carbon atoms that may have substituents; R 10 ~R 13 Each of the following can independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkyl carbonyloxy group having 2 to 11 carbon atoms, an aryloxy group having 4 to 10 carbon atoms, an aryl carbonyloxy group having 5 to 11 carbon atoms, an alkyl group having 1 to 6 carbon atoms and / or a silyloxy group having a phenyl group, or a halogen atom, and Ar represents a divalent organic group represented by formula (5), (6) or (7) below.

[0071]

[0072] (where R) 14 ~R 20 Each of these groups independently represents a hydrogen atom, an alkyl group with 1 to 10 carbon atoms that may have substituents, or an aryl group with 6 to 10 carbon atoms that may have substituents. These substituents are groups that can react with isocyanate groups. The symbol * indicates a bonding site.

[0073] R in equations (3-1), (3-2), (4-1) and (4-2) 4 -O- or -NR 5 -, R 5 R is an alkyl group having 1 to 5 carbon atoms or hydrogen atoms. In formulas (3-1), (3-2), (4-1), and (4-2), R... 4 Preferred -O-.

[0074] R in equations (3-1) and (4-1) 6 and R 7Each of these can be a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a haloalkyl group having 1 to 5 carbon atoms, or an aryl group having 6 to 10 carbon atoms. As an alkyl group having 1 to 5 carbon atoms, it can have a branched structure or a cyclic structure, and examples include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, neopentyl, cyclopentyl, etc. As alkyl halides with 1 to 5 carbon atoms, they can have branched or cyclic structures. Examples include fluoromethyl, trifluoromethyl, bromodifluoromethyl, 2-chloroethyl, 2-bromoethyl, 1,1-difluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, 2-chloro-1,1,2-trifluoroethyl, pentafluoroethyl, 3-bromopropyl, 2,2,3,3-tetrafluoropropyl, 1,1,2,3,3,3-hexafluoropropyl, 1,1,1,3,3,3-hexafluoropropane-2-yl, 3-bromo-2-methylpropyl, 2,2,3,3-tetrafluorocyclopropyl, 4-bromobutyl, perfluoropentyl, and perfluorocyclopentyl. As aryl groups with 6 to 10 carbon atoms, examples include phenyl, tolyl, xylyl, and naphthyl.

[0075] R in equations (3-1) and (4-1) 6 and R 7 Each of the components is preferably a halogenated alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms, and more preferably a trifluoromethyl or phenyl group.

[0076] R in equations (4-1) and (4-2) 8 and R 9 Each alkyl group is a hydrogen atom and may have substituents; it can be an alkyl group with 1 to 10 carbon atoms or an aryl group with 6 to 10 carbon atoms. Alkyl groups with 1 to 10 carbon atoms can have branched or cyclic structures, and can also be arylalkyl groups, such as methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, cyclopentyl, n-hexyl, cyclohexyl, n-octyl, n-decyl, 1-adamantyl, benzyl, phenethyl, etc. Aryl groups with 6 to 10 carbon atoms can be such as phenyl, tolyl, xylyl, naphthyl, etc. Examples of substituents include amino, hydroxyl, carboxyl, epoxy, methoxycarbonyl, tert-butoxycarbonyl, and other alkoxycarbonyl groups; trimethylsilyloxy, tert-butyldimethylsilyloxy, tert-butyldiphenylsilyloxy, triphenylsilyloxy, and other silyloxy groups; and halogen atoms such as fluorine, chlorine, bromine, and iodo groups. It should be noted that the bonding site of the aforementioned group (Z) is preferably derived from the aforementioned R. 8 Or R 9 The bonding sites of the groups that can react with isocyanate groups.

[0077] R in equations (4-1) and (4-2) 8 and R 9 Each of the substituents is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms. The substituent is preferably a hydroxyl group.

[0078] R in equations (4-1) and (4-2) 10 ~R 13 Each of the following is independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkyl carbonyloxy group having 2 to 11 carbon atoms, an aryloxy group having 4 to 10 carbon atoms, an aryl carbonyloxy group having 5 to 11 carbon atoms, an alkyl group having 1 to 6 carbon atoms, and / or a silyloxy group having a phenyl group, or a halogen atom. Examples of alkyl groups having 1 to 10 carbon atoms include the aforementioned R. 8 and R 9 Examples of the groups shown are: Alkoxy groups having 1 to 10 carbon atoms, for example, groups formed by bonding an alkyl group having 1 to 10 carbon atoms via an oxygen atom. Alkyl carbonyloxy groups having 2 to 11 carbon atoms, for example, groups formed by bonding an alkyl group having 1 to 10 carbon atoms via a carbonyloxy group. Aryloxy groups having 4 to 10 carbon atoms, for example, phenoxy, benzyloxy, naphth-2-yloxy, furan-3-yloxy, thiophene-2-yloxy, etc. Aryl carbonyloxy groups having 5 to 11 carbon atoms, for example, benzoyloxy, 1-naphthoyloxy, furan-2-carbonyloxy, thiophene-3-carbonyloxy, etc. Alkyl groups having 1 to 6 carbon atoms and / or silyloxy groups having a phenyl group, for example, trimethylsilyloxy, tert-butyldimethylsilyloxy, tert-butyldiphenylsilyloxy, triphenylsilyloxy, etc. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine groups.

[0079] R in equations (4-1) and (4-2) 10 ~R 13 Each of the components is preferably a hydrogen atom or an aryloxy group having 4 to 10 carbon atoms, and more preferably a hydrogen atom or a benzyloxy group.

[0080] R in equations (5) to (7) 14 ~R 20 Each of these groups independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may also have substituents. These substituents can also be groups that react with isocyanate groups. Examples of alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and substituents include the aforementioned R groups. 8 and R 9The group shown in the example.

[0081] In formulas (4-1) and (4-2), Ar is a divalent organic group represented by formulas (5), (6) or (7) above, preferably a divalent organic group represented by formula (6), and R in formula (6) 18 and R 19 Hydrogen atoms are preferred.

[0082] <Repeating structural unit (C)>

[0083] To adjust the content of nonlinear optically active sites and Tg, to improve the solvent resistance of molded articles (e.g., cured films) obtained using the copolymers of the present invention, and to suppress orientation relaxation, or to enable the formation of molded articles by thermosetting, the copolymers of the present invention may contain repeating structural units (C) with structures different from the repeating structural units (A) and (B) described above. The repeating structural units (C) may include one type or more types.

[0084] The copolymer of the present invention is intended to be used as an optically active material, such as the core of an optical waveguide, and the aforementioned repeating structural unit (C) is preferably a structural unit that will not adversely affect the transparency and formability of the copolymer.

[0085] Examples of repeating structural units (C) mentioned above include those derived from monomers such as alkyl methacrylates, alkoxy-containing methacrylates, alicyclic methacrylates, aryl methacrylates, hydroxyl methacrylates, epoxy methacrylates, carboxyl methacrylates, and isocyanate methacrylates.

[0086] Examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, sec-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, n-nonyl methacrylate, isononyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, isostearyl methacrylate, eicosyl methacrylate, behenyl methacrylate, and tetrahydrofurfuryl methacrylate.

[0087] Examples of alkoxy-containing (meth)acrylates include 2-methoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and ethyl carbitol (meth)acrylate.

[0088] Examples of (meth)acrylates containing alicyclic groups include cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and adamantyl (meth)acrylate.

[0089] Examples of aryl-containing (meth)acrylates include phenyl (meth)acrylate, benzyl (meth)acrylate, and phenoxyethyl (meth)acrylate, which contain aryl groups with 6 to 15 carbon atoms.

[0090] Examples of hydroxyl-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate.

[0091] Examples of epoxy-containing (meth)acrylates include glycidyl (meth)acrylate and epoxycyclohexyl (meth)acrylate.

[0092] Examples of carboxyl-containing (meth)acrylates include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxybutyl (meth)acrylate, and carboxypentyl (meth)acrylate.

[0093] Examples of (meth)acrylates containing isocyanate groups include (meth)acryloyloxyethyl isocyanate.

[0094] In addition, examples of the repeating structural unit (C) mentioned above include structural units derived from monomers such as 2-(meth)acryloyloxyethylsuccinic acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride, vinyl acetate, vinyl propionate, styrene, α-methylstyrene, N-vinylcaprolactam, cyclohexylmaleimide, phenylmaleimide, methylmaleimide, ethylmaleimide, n-butylmaleimide, laurylmaleimide, and monomers containing organosilicon.

[0095] Furthermore, examples of the aforementioned repeating structural unit (C) include structural units derived from resins such as poly(meth)acrylate, polycarbonate, polystyrene, silicone resins, epoxy resins, polysulfone, polyethersulfone, and polyimide. By introducing these repeating structural units that form a polymer matrix into the copolymer of the present invention, a copolymer of the aforementioned repeating structural unit (A), the aforementioned repeating structural unit (B), and the repeating structural unit (C) of the polymer matrix can be formed.

[0096] Furthermore, in order to form a molded article by thermosetting, repeating structural units (C) having a thermosetting (crosslinking) structure can be introduced into the copolymer of the present invention. Examples of such thermosetting (crosslinking) structures include isocyanate groups protected by a capping agent. As the aforementioned end-capping agent, there are no particular limitations as long as it is an end-capping agent that can be regenerated by heating (de-capping) to regenerate the active isocyanate group. Examples include phenols such as phenol, o-nitrophenol, p-chlorophenol, o-, m-, or p-cresol; alcohols such as methanol, ethanol, isopropanol, n-butanol, 2-ethoxyhexanol, 2-N,N-dimethylaminoethanol, 2-ethoxyethanol, and cyclohexanol; compounds containing active methylene groups such as dimethyl malonate, diethyl malonate, and methyl acetoacetate; oximes such as acetone oxime, methyl ethyl ketone oxime, methyl isobutyl ketone oxime, cyclohexanone oxime, acetophenone oxime, and benzophenone oxime; lactams such as ε-caprolactam; pyrazoles such as pyrazole, 3,5-dimethylpyrazole, and 3-methylpyrazole; and thiols such as dodecyl mercaptan and benzyl mercaptan.

[0097] As a repeating unit having a structure capable of thermosetting (crosslinking), the repeating structural unit represented by the following formula (8) can be cited as an example.

[0098] (8)

[0099] (where R) 21 L represents a hydrogen atom or a methyl group. 4 (This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds; Y indicates an isocyanate group protected by a capping agent.)

[0100] For L in equation (8) 4 As a divalent hydrocarbon group with 1 to 30 carbon atoms, examples similar to the L mentioned above can be cited. 2 and L 3 The groups are the same as those shown in the examples.

[0101] <Content rate of each repeating structural unit>

[0102] In the copolymer of the present invention, the content of the repeating structural units (A) and (B) in the copolymer of the present invention (in 100 mol% of the total repeating structural units) is not particularly limited. From the viewpoint of suppressing film cracking even when the film is thick, and from the viewpoint of film-forming properties, it is preferable that the content of the repeating structural unit (A) is 5 to 95 mol% and the content of the repeating structural unit (B) is 5 to 95 mol%, more preferably that the content of the repeating structural unit (A) is 20 to 90 mol% and the content of the repeating structural unit (B) is 10 to 50 mol%, and even more preferably that the content of the repeating structural unit (A) is 35 to 85 mol% and the content of the repeating structural unit (B) is 15 to 20 mol%.

[0103] Furthermore, when the copolymer of the present invention comprises the above-mentioned repeating structural units (A) and (B) and the above-mentioned repeating structural unit (C), from the viewpoint of improving the electro-optic effect and suppressing the formation of cracks in the film even when the film is thick, the content of the above-mentioned repeating structural unit (C) in the copolymer of the present invention (in 100 mol% of the total repeating structural units) is preferably 90 mol% or less, more preferably 1 to 50 mol%, further preferably 2 to 10 mol%, and particularly preferably 3 to 5 mol%.

[0104] <Morphology of Copolymers>

[0105] Examples of the copolymer forms of the present invention include linear, cross-linked, and mesh-like forms. For example, the copolymers of the present invention are cross-linked or mesh-like forms when they contain the repeating structural unit (B2) represented by formula (2-2) above. By using cross-linked or mesh-like copolymers of the present invention, film cracking can be more effectively suppressed during film formation. Furthermore, by making the copolymers of the present invention cross-linked or mesh-like, the glass transition temperature can be increased, thereby suppressing the orientation relaxation of nonlinear optically active sites caused by heat and suppressing the reduction of electro-optic effects caused by heat.

[0106] <Weight-average molecular weight of copolymer>

[0107] The weight-average molecular weight of the copolymers of the present invention is not particularly limited, for example, it is 10,000 to 200,000, and from the viewpoint of solubility, it is preferably 10,000 to 150,000, more preferably 10,000 to 100,000. It should be noted that the weight-average molecular weight in the present invention refers to the value measured by gel permeation chromatography (polystyrene conversion).

[0108] <Glass transition temperature of copolymers>

[0109] The glass transition temperature (Tg) of the copolymer of the present invention is not particularly limited. From the viewpoint of suppressing the formation of cracks in the film even when the film is thick, and from the viewpoint of heat resistance, the midpoint of Tg is preferably 130 to 200°C, and more preferably 150 to 200°C.

[0110] <Viscosity of the copolymer>

[0111] The viscosity of the copolymer of the present invention is not particularly limited, but is typically around 20 to 400 cP in a 20% by weight cyclohexanone solution (25°C). From the viewpoint of coatability, it is preferably 20 to 300 cP, and more preferably 20 to 200 cP.

[0112] <Methods for manufacturing copolymers>

[0113] The method for manufacturing the copolymer of the present invention is not particularly limited, and any known manufacturing method can be used. For example, it can be obtained by copolymerizing a (meth)acrylic acid derivative having an alkoxyadamantyl group and / or a (meth)acrylamide derivative with a (meth)acrylic acid derivative having a functional group for introducing a nonlinear optically active site, and then reacting the compound having the nonlinear optically active site with the aforementioned functional group. Examples of functional groups for introducing a nonlinear optically active site include isocyanate groups, hydroxyl groups, carboxyl groups, epoxy groups, amino groups, halogenated allyl groups, and halogenated acyl groups. For example, by reacting an (meth)acrylic acid derivative having an alkoxyadamantyl group and / or a (meth)acrylamide derivative with a (meth)acrylic acid derivative having an isocyanate group, and then reacting a compound having a functional group capable of reacting with an isocyanate group and a nonlinear optically active site within the same molecule, the copolymer of the present invention can be obtained. There are no particular limitations on the functional groups capable of reacting with isocyanate groups; examples include groups having active hydrogen such as hydroxyl, amino, and carboxyl groups, and epoxy groups capable of generating active hydrogen. As a nonlinear optically active site, examples can be given of organic nonlinear optical compounds derived from the descriptions of Z (atom groups exhibiting nonlinear optical activity) in formulas (2-1) and (2-2) above, with the atom group represented by formula (3) above being preferred. As a compound having a functional group capable of reacting with an isocyanate group and a nonlinear optically active site within the same molecule, examples can be given of compounds represented by formulas (4-1) and (4-2) above. By reacting the hydroxyl or amino groups present in the compound with the isocyanate group, the repeating structural unit (B1) represented by formula (2-1) or the repeating structural unit (B2) represented by formula (2-2) above can be obtained.

[0114] <Uses of Copolymers>

[0115] The copolymers of the present invention are suitable for use as materials in electro-optical components such as optical switches, optical modulators, and phase shifters. Furthermore, in addition to applications in communication components, the copolymers of the present invention can also be used in applications such as electric field sensors that detect changes in refractive index based on changes in the electric field.

[0116] 2. Composition

[0117] The compositions of the present invention comprise the copolymers and solvents of the present invention.

[0118] The solvents mentioned above are not particularly limited as long as they can dissolve or disperse the copolymers of the present invention; examples include tetrahydrofuran, methyltetrahydrofuran, and 1,4-dihydrofuran. Alkane, diethylene glycol dimethyl ether, acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl acetate, cyclohexanol, 1,2-dichloroethane, chloroform, toluene, chlorobenzene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, chlorobenzene, propylene glycol methyl ether, etc. These solvents can be used alone or in combination of two or more. From the viewpoint of high solubility and good coatability of the copolymers of the present invention, at least one solvent selected from tetrahydrofuran, cyclopentanone, and chloroform is preferred.

[0119] The content of the copolymer of the present invention in the composition is not particularly limited, and is generally about 3 to 30% by weight. From the viewpoint of coatability and ease of film thickening using a high concentration of the composition, it is preferably 3 to 25% by weight, and more preferably 3 to 20% by weight. It should be noted that the prepared composition is preferably used after filtration with a filter or the like with a pore size of about 200 nm to remove insoluble matter.

[0120] Provided that the effects of the present invention are not impaired, the composition of the present invention may contain additives such as hydroquinone and other antioxidants, benzophenone and other ultraviolet absorbers, silicone oil, surfactants and other rheology modifiers, silane coupling agents and other adhesive aids, crosslinking agents, compatibilizers, curing agents, pigments, preservation stabilizers and defoamers as needed.

[0121] 3. Nonlinear optical materials

[0122] <Nonlinear Optical Materials A>

[0123] One aspect of the nonlinear optical material A of the present invention comprises the copolymer of the present invention.

[0124] In the nonlinear optical material A of the present invention, the content of the copolymer of the present invention is not particularly limited, and is usually 85% by weight or more, preferably 90 to 100% by weight, more preferably 95 to 100% by weight, and even more preferably 99 to 100% by weight.

[0125] The nonlinear optical material A of the present invention may further comprise a nonlinear optically active compound. Known inorganic and / or organic nonlinear optically active compounds may be used as the nonlinear optically active compound without particular limitation, but organic nonlinear optically active compounds are preferred.

[0126] Examples of inorganic nonlinear optically active compounds include lithium niobate, potassium dihydrogen phosphate, and zinc telluride. They may contain one or more of these compounds.

[0127] Examples of organic nonlinear optically active compounds include compounds represented by formulas (4-1) and (4-2) above, US Patent No. 6067186, Japanese Patent Publication No. 2004-501159, International Publication No. 2011 / 024774, International Publication No. 2023 / 021921, "Organic Materials for Nonlinear Optics" (edited by the Chemical Society of Japan, Quarterly Review of Chemistry No. 15 (1992)), "Organic Nonlinear Optical Materials" (Ch. Bosshard, et al., Gordon and Breach Publishers (1995)), "Latest Technologies in Optical Organic Materials for Information and Communication" (supervised by Toshikuni Kageno, CMC Publishing (2007)), and "Molecular Nonlinear Optics" (ed. J. Zyss, Academic Press (1994)), which exhibit second-order nonlinear optical effects. These compounds may contain one or more of these compounds.

[0128] Furthermore, there are no particular limitations on organic nonlinear optically active compounds, as long as they exhibit second-order nonlinear optical effects. Preferred compounds are those with a conjugated chemical structure and, more preferably, electron-donating and electron-withdrawing groups within the molecule. Examples of conjugated chemical structures include, for instance, aromatic compounds such as benzene, naphthalene, anthracene, perylene, biphenyl, indene, and brunc; heterocyclic compounds such as furan, pyran, pyrrole, imidazole, pyrazole, thiophene, thiazole, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, and coumarin; and chemical structures formed by these compounds being bonded together via carbon-carbon unsaturated bonds or nitrogen-nitrogen unsaturated bonds.

[0129] Examples of electron-donating groups include amino, alkoxy, allyloxy, and thioether groups that can be substituted with alkyl, aryl, or acyl groups. Examples of electron-withdrawing groups include nitro, cyano, dicyanovinyl, tricyanovinyl, halogen atoms, carbonyl, sulfonyl, perfluoroalkyl, tricyanovinylfuran, and tricyanofuran.

[0130] The organic nonlinear optically active compound is preferably a compound represented by formula (4-1) and / or (4-2) above.

[0131] In the case where the nonlinear optical material A of the present invention contains a nonlinear optically active compound, the content of the nonlinear optically active compound can be appropriately adjusted according to the intended use of the nonlinear optical material A.

[0132] The nonlinear optical material A of the present invention may further comprise the following polymer (hereinafter also referred to as "polymer X"): comprising repeating structural units (A) having adamantyl alkyl groups as represented by the above formula (1), and not containing repeating structural units (B) having nonlinear optical active sites.

[0133] The polymer X described above can be a homopolymer composed of the repeating structural unit (A) or a copolymer comprising the repeating structural unit (A) and the repeating structural unit (C). When the polymer X is a copolymer, it can be a random copolymer or a block copolymer.

[0134] When the nonlinear optical material A of the present invention contains the polymer X described above, the content of the polymer X can be appropriately adjusted according to the application of the nonlinear optical material A, etc.

[0135] The nonlinear optical material A of the present invention may contain additives such as hydroquinone and other antioxidants, benzophenone and other ultraviolet absorbers, silicone oil, surfactants and other rheology modifiers, silane coupling agents and other adhesive aids, crosslinking agents, compatibilizers, curing agents, pigments, preservation stabilizers and defoamers as needed.

[0136] <Nonlinear Optical Materials B>

[0137] Another aspect of the present invention provides a nonlinear optical material B comprising the aforementioned polymer X and the aforementioned nonlinear optically active compound.

[0138] In the nonlinear optical material B of the present invention, the contents of the polymer X and the nonlinear optical active compound can be appropriately adjusted according to the intended use of the nonlinear optical material B.

[0139] The nonlinear optical material B of the present invention may contain the above-mentioned additives as needed.

[0140] <Morphology of Nonlinear Optical Materials>

[0141] The form of the nonlinear optical material of the present invention is not particularly limited, and it is usually in the form of a film. When the nonlinear optical material of the present invention is in the form of a film, there are no particular limitations on the manufacturing method of the film. For example, the following wet coating method can be used: the raw materials of the nonlinear optical material of the present invention are dissolved or dispersed in the above-mentioned solvent to form a composition (preferably a solution), and the composition is coated onto a suitable substrate (e.g., silicon / silica coated substrate, silicon nitride substrate, substrate coated with metal (e.g., aluminum, molybdenum, chromium, etc.), glass substrate, quartz substrate, ITO substrate, etc.) or film (e.g., triacetyl cellulose film, polyester film, acrylic film, etc. resin film) by spin coating, dip coating, spray coating, rod coating, flow coating, gravure coating, roll coating, etc., thereby forming a film.

[0142] Then, in order to exhibit second-order nonlinear optical properties, the prepared film is subjected to a polarization treatment. The polarization treatment involves heating the copolymer or nonlinear optically active compound of the present invention at a temperature near its glass transition temperature, applying a predetermined electric field in this state, and cooling it while maintaining the electric field, thereby orienting the nonlinear optically active sites (atomic groups exhibiting nonlinear optical activity) contained therein. Through this operation, the film (nonlinear optical material) can exhibit macroscopic nonlinear optical properties.

[0143] When the nonlinear optical material of the present invention is in the form of a film, its thickness is not particularly limited, and is typically about 0.1 to 10 μm, preferably 0.3 to 3.0 μm, and more preferably 0.5 to 2.0 μm. Since the nonlinear optical material of the present invention contains the copolymer of the present invention and / or the aforementioned polymer X, cracks are less likely to occur even when the film is thick.

[0144] <Properties of Nonlinear Optical Materials>

[0145] The refractive index (n) of the nonlinear optical material of the present invention is not particularly limited. For example, it is usually about 1.5 to 1.7 at a wavelength of 1308 nm, and also usually about 1.5 to 1.7 at a wavelength of 1532 nm.

[0146] The electro-optic coefficient (r) of the nonlinear optical material of the present invention is not particularly limited. For example, it is usually about 85 to 105 pm / V at a wavelength of 1308 nm, and usually about 50 to 75 pm / V at a wavelength of 1550 nm.

[0147] The performance index (n) of the nonlinear optical material of the present invention 3 r) There are no special restrictions. For example, at a wavelength of 1308nm, it is usually around 370 to 470 pm / V. In addition, at a wavelength of 1550nm, it is usually around 225 to 300 pm / V.

[0148] 4. Electro-optical components

[0149] The electro-optical elements of the present invention comprise the copolymers of the present invention or the nonlinear optical materials of the present invention. The copolymers of the present invention are suitable as materials for various electro-optical elements. Examples of such electro-optical elements include optical switches, optical modulators, and phase shifters.

[0150] Representative examples of electro-optical components include optical switching elements (optical communication elements) such as Mach-Zehnder type optical modulators. In optical switching elements, a composition (solution) containing the copolymer of the present invention is coated onto a substrate such as glass or plastic, and then processed using photolithography based on light or electron beams, wet and dry etching methods, or nanoimprinting, thereby forming an optical waveguide structure capable of transmitting light. Typically, the composition (solution) is coated onto a material with a refractive index lower than that of the composition (solution) containing the copolymer of the present invention and then laminated to form an optical waveguide structure; however, this is not limited to this structure, and the composition (solution) containing the copolymer of the present invention can also be applied to other optical waveguide structures.

[0151] In Mach-Zehnder type optical modulators, electro-optical properties are exhibited by applying a high-frequency voltage to one or both of the branched optical waveguide structures, thereby changing their refractive index and producing a phase change in the propagating light. This phase change alters the intensity of the branched and combined light, enabling high-speed modulation of the light.

[0152] The electro-optical elements of the present invention are not limited to phase and intensity modulation, but can also be used, for example, as polarization conversion elements, wave splitting and wave combining elements, etc.

[0153] Optical waveguides using the copolymers of the present invention as core materials can be manufactured, for example, by the method disclosed in International Publication No. 2016 / 035823.

[0154] Example

[0155] The following examples illustrate the present invention, but the present invention is not limited to these examples.

[0156] In the embodiments and comparative examples, the abbreviations are as follows.

[0157] AdOMe: 3-Methoxy-1-adamantyl methacrylate

[0158] AdOEt: 3-ethoxy-1-adamantyl methacrylate

[0159] MOI: Ethyl 2-isocyanate methacrylate (manufactured by Showa Denko Co., Ltd., Karenz MOI (registered trademark))

[0160] AdMA: 1-Adamantate methacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Adamantate M-104)

[0161] DCPMA: Dicyclopentyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0162] AIBN: 2,2'-azobis(isobutyronitrile) (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0163] DBTDL: Dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0164] THF: Tetrahydrofuran

[0165] Synthesis example 1

[0166] [Synthesis of AdOMe]

[0167] 118 g of 3-hydroxy-1-adamantyl methacrylate (manufactured by Osaka Organic Chemical Industry, Adamantate HM), 1000 g of toluene, and 76 g of triethylamine were placed in a 2000 mL four-necked flask equipped with a Dianestar splitter and a stirrer, and cooled to below 5°C. 69 g of methanesulfonyl chloride was added dropwise, and the reaction was allowed to proceed for 1 hour. Then, 600 g of water was added, and the organic layer was separated by liquid-liquid extraction. The obtained organic layer was washed with 500 g of 3% hydrochloric acid, followed by 500 g of water. The solvent was then concentrated to obtain 140 g of 3-methanesulfonyloxy-1-adamantyl methacrylate.

[0168] 22 g of the obtained 3-methanesulfonyloxy-1-adamantyl methacrylate, 140 g of methanol, and 12 g of triethylamine were added to a 500 mL four-necked flask equipped with a Diane-Dacco splitter and a stirrer, and the reaction was carried out at 65 °C for 30 hours. The resulting reaction solution was concentrated, and methanol was removed by distillation. Then, 25 g of hexane, 10 g of toluene, and 50 g of water were added, and the organic layer was separated by liquid-liquid extraction. The obtained organic layer was washed with 50 g of 2% hydrochloric acid, followed by 50 g of water, and then the solvent was concentrated to obtain a concentrated solution. The concentrated solution was purified by distillation to obtain 17 g of AdOMe as a colorless and transparent liquid.

[0169] Synthesis example 2

[0170] [Synthesis of AdOEt]

[0171] Alcohol was used instead of methanol in Synthesis Example 1 to react with 3-methanesulfonyloxy-1-adamantyl methacrylate. Otherwise, the reaction was carried out in the same manner as in Synthesis Example 1 to synthesize AdOEt.

[0172] Manufacturing Example 1

[0173] [Preparation of nonlinear optically active compounds]

[0174] The following compound, [FTC-OH], is used as a nonlinear optically active compound. [FTC-OH] is prepared by the same method disclosed in X. Zhang et al., Tetrahedron Lett., 51, p5823 (2010).

[0175]

[0176] Manufacturing Example 2

[0177] [Preparation of nonlinear optically active compounds]

[0178] The following compound, [FTC-OH2], is used as a nonlinear optically active compound. [FTC-OH2] is prepared by the same method disclosed in X. Piao et al., J. Polym. Sci., A, Polym. Chem., 49, p47 (2011).

[0179] [FTC-OH2]

[0180] Example 1 (Preparation of the copolymer)

[0181] (1) Manufacturing of intermediates

[0182] Under an argon atmosphere, 8.863 g (35.4 mmol) of AdOMe, 1.350 g (8.70 mmol) of MOI, and 0.354 g (2.16 mmol) of AIBN were dissolved in 20 mL of dehydrated toluene. The resulting solution was added dropwise over 20 minutes to 20 mL of dehydrated toluene heated to 70 °C. The mixture was then stirred at 72–75 °C for 2 hours. After cooling to room temperature (approximately 23 °C), the resulting reaction mixture was added dropwise to 500 mL of dehydrated IPE (isopropyl ether) to precipitate the polymer. The precipitate was filtered, washed successively with dehydrated IPE and dehydrated hexane, and then dried under reduced pressure at 70 °C to obtain 8.41 g of an intermediate as a white powder containing repeating structural units from AdOMe and MOI.

[0183] (2) Manufacturing of copolymers with nonlinear optically active sites

[0184] Under an argon atmosphere, 1.15 g of the above intermediate (0.98 mmol based on isocyanate groups), 0.525 g (0.76 mmol) of the nonlinear optically active compound [FTC-OH] prepared in Manufacturing Example 1, and approximately 100 mg of DBTDL were dissolved in 40 ml of dehydrated THF and stirred at 50–55 °C for 2 hours. Then, approximately 5 ml of methanol was added, and the mixture was stirred further at 50–55 °C for 1 hour. The resulting reaction mixture was precipitated with 450 ml of IPE, and the precipitate was filtered. The crude product was added to 150 ml of THF, heated to 60 °C to dissolve, dispersed in 1500 ml of IPE, and reprecipitated. The precipitate was filtered, washed, and dried under reduced pressure at 70 °C to obtain 1.22 g of a copolymer of dark reddish-brown powder having the following repeating structural units (A1), (B1), and (C1). The following formulas, from left to right, represent the repeating structural units (A1), (B1), and (C1).

[0185]

[0186] Example 2 (Preparation of the copolymer)

[0187] (1) Manufacturing of intermediates

[0188] 8.910 g (33.7 mmol) of AdOEt, 1.359 g (8.76 mmol) of MOI, and 0.355 g (2.16 mmol) of AIBN were dissolved in 20 mL of dehydrated toluene under an argon atmosphere. The resulting solution was added dropwise over 20 minutes to 20 mL of dehydrated toluene heated to 70 °C. The mixture was then stirred at 72–75 °C for 2 hours. After cooling to room temperature (approximately 23 °C), the resulting reaction mixture was added dropwise to 500 mL of dehydrated IPE to precipitate the viscous polymer. After removing the supernatant, 600 mL of dehydrated IPE was added to solidify the mixture. After removing the supernatant, the mixture was dried under reduced pressure at 45 °C to obtain 6.31 g of a white powder intermediate containing repeating structural units from AdOEt and MOI.

[0189] (2) Manufacturing of copolymers with nonlinear optically active sites

[0190] Under an argon atmosphere, 1.17 g of the above intermediate (0.998 mmol based on isocyanate groups), 0.525 g (0.76 mmol) of the nonlinear optically active compound [FTC-OH] prepared in Example 1, and approximately 100 mg of DBTDL were dissolved in 40 ml of dehydrated THF and stirred at 50–55 °C for 2 hours. Then, approximately 5 ml of methanol was added, and the mixture was stirred further at 50–55 °C for 1 hour. The resulting reaction mixture was precipitated with 450 ml of IPE and 450 ml of MeOH, and the precipitate was filtered. The crude product was washed with IPE:THF 10:1, followed by washing with IPE, and finally washing with MeOH. Then, it was dried under reduced pressure at 70 °C to obtain 1.31 g of a copolymer of dark reddish-brown powder having the following repeating structural units (A2), (B1), and (C1). The following formulas represent the repeating structural units (A2), (B1), and (C1) sequentially from the left side.

[0191]

[0192] Example 3 (Preparation of the copolymer)

[0193] (1) Manufacturing of intermediates

[0194] Under an argon atmosphere, 4.49 g (17.9 mmol) of AdOMe, 3.96 g (18.0 mmol) of AdMA, 1.29 g (8.31 mmol) of MOI, and 0.25 g (1.52 mmol) of AIBN were dissolved in 20 mL of dehydrated toluene. The resulting solution was added dropwise over 20 minutes to 20 mL of dehydrated toluene heated to 70 °C. The mixture was then stirred at 72–75 °C for 2 hours. After cooling to room temperature (approximately 23 °C), the resulting reaction mixture was added dropwise to 450 mL of dehydrated IPE to precipitate the polymer. The precipitate was filtered, washed successively with dehydrated IPE and dehydrated hexane, and then dried under reduced pressure at 70 °C to obtain 7.06 g of a white powder intermediate containing repeating structural units from AdOMe, AdMA, and MOI.

[0195] (2) Manufacturing of copolymers with nonlinear optically active sites

[0196] Under an argon atmosphere, 1.25 g of the above intermediate (1.07 mmol based on isocyanate groups), 0.558 g (0.808 mmol) of the nonlinear optically active compound [FTC-OH] prepared in Preparation Example 1, and approximately 100 mg of DBTDL were dissolved in 45 ml of dehydrated THF and stirred at 50–55 °C for 2 hours. Then, approximately 5 ml of methanol was added, and the mixture was stirred further at 50–55 °C for 1 hour. The resulting reaction mixture was precipitated with 450 ml of IPE, and the precipitate was filtered. The crude product obtained by washing with IPE:THF (10:1), followed by washing with IPE, and finally washing with MeOH was added to 100 ml of THF, heated to 60 °C to dissolve, dispersed in 1000 ml of IPE, and reprecipitated. The precipitate was filtered, washed with IPE:THF (10:1), then with IPE, and finally with MeOH. The mixture was then dried under reduced pressure at 70°C to obtain 1.47 g of a copolymer of dark reddish-brown powder containing the repeating structural units (C2), (A1), (B1), and (C1). The following formulas, from left to right, represent the repeating structural units (C2), (A1), (B1), and (C1).

[0197]

[0198] Example 4 (Preparation of the copolymer)

[0199] (1) Manufacturing of intermediates

[0200] 8.87 g (35.4 mmol) of AdOMe, 1.42 g (9.15 mmol) of MOI, and 0.354 g (2.16 mmol) of AIBN were dissolved in 18 mL of dehydrated toluene under an argon atmosphere and stirred at 70 °C for 2 hours. After cooling to room temperature (approximately 23 °C), the resulting reaction mixture was added to 450 mL of dehydrated IPE to precipitate the polymer. The precipitate was filtered, then washed successively with dehydrated IPE and dehydrated hexane, and then dried under reduced pressure at 70 °C to obtain 8.91 g of an intermediate as a white powder containing repeating structural units from AdOMe and MOI.

[0201] (2) Manufacturing of copolymers with nonlinear optically active sites

[0202] Under an argon atmosphere, 1.15 g of the above intermediate (1.02 mmol based on isocyanate groups), 0.525 g (0.76 mmol) of the nonlinear optically active compound [FTC-OH] prepared in Manufacturing Example 1, and approximately 100 mg of DBTDL were dissolved in 40 ml of dehydrated THF and stirred at 50–55 °C for 2 hours. Then, approximately 5 ml of methanol was added, and the mixture was stirred further at 50–55 °C for 1 hour. The resulting reaction mixture was precipitated with 450 ml of IPE, and the precipitate was filtered. The crude product was added to 50 ml of THF, heated to 60 °C to dissolve, dispersed in 500 ml of IPE, and reprecipitated. The precipitate was filtered, washed, and dried under reduced pressure at 70 °C to obtain 1.28 g of a copolymer of dark reddish-brown powder having the following repeating structural units (A1), (B1), and (C1). The following formulas, from left to right, represent the repeating structural units (A1), (B1), and (C1).

[0203]

[0204] Example 5 (Preparation of the copolymer)

[0205] (1) Manufacturing of intermediates

[0206] 4.65 g (18.6 mmol) of AdOMe, 4.13 g (26.6 mmol) of MOI, and 0.222 g (1.35 mmol) of AIBN were dissolved in 14.5 mL of dehydrated toluene under an argon atmosphere and stirred at 70 °C for 2 hours. After cooling to room temperature (approximately 23 °C), the reaction mixture was added to 370 mL of dehydrated IPE to precipitate the polymer. The precipitate was filtered, washed with dehydrated IPE, and then dried under reduced pressure at 70 °C to obtain 7.05 g of an intermediate as a white powder containing repeating structural units from AdOMe and MOI.

[0207] (2) Manufacturing of copolymers with nonlinear optically active sites

[0208] Under an argon atmosphere, 1.53 g of the above intermediate (4.63 mmol based on isocyanate groups), 0.841 g (1.17 mmol) of the nonlinear optically active compound [FTC-OH2] prepared in Manufacturing Example 2, 0.421 g (1.34 mmol) of DR1 (Disperse Red 1), and approximately 160 mg of DBTDL were dissolved in 90 ml of dehydrated THF and stirred at 55–56 °C for 2 hours. Then, 5.3 ml of methanol and approximately 60 mg of DBTDL were added, and the mixture was further stirred at 53–55 °C for 1 hour. The resulting reaction mixture was precipitated with 1050 ml of IPE, and the precipitate was filtered. The precipitate was washed with IPE:THF (12:1), followed by washing with IPE, and finally washing with hexane. The precipitate was then dried under reduced pressure at 70 °C to obtain 2.55 g of a copolymer of dark brown powder having the following repeating structural units (A1), (B2), (C1), and (C4). The following formulas, from left to right, represent the repeating structural units (A1), (B2), (C1), and (C4).

[0209]

[0210] Comparative Example 1 (Preparation of Copolymer)

[0211] (1) Manufacturing of intermediates

[0212] Under an argon atmosphere, 8.38 g (38.0 mmol) of AdMA, 1.258 g (8.11 mmol) of MOI, and 0.387 g (2.16 mmol) of AIBN were dissolved in 20 mL of dehydrated toluene. The resulting solution was added dropwise over 20 minutes to 20 mL of dehydrated toluene heated to 70 °C. The mixture was then stirred at 72–75 °C for 2 hours. After cooling to room temperature (approximately 23 °C), the resulting reaction mixture was added dropwise to 450 mL of dehydrated IPE to precipitate the polymer. The precipitate was filtered, washed successively with dehydrated IPE and dehydrated hexane, and then dried under reduced pressure at 70 °C to obtain 6.74 g of a white powder intermediate containing repeating structural units from AdMA and MOI.

[0213] (2) Manufacturing of copolymers with nonlinear optically active sites

[0214] Under an argon atmosphere, 1.24 g of the above intermediate (1.04 mmol based on isocyanate groups), 0.554 g (0.802 mmol) of the nonlinear optically active compound [FTC-OH] prepared in Manufacturing Example 1, and approximately 100 mg of DBTDL were dissolved in 40 ml of dehydrated THF and stirred at 50–55 °C for 2 hours. Then, approximately 5 ml of methanol was added, and the mixture was stirred further at 50–55 °C for 1 hour. The resulting reaction mixture was precipitated with 500 ml of IPE. The precipitate was filtered, washed, and dried under reduced pressure at 70 °C to obtain 1.49 g of a copolymer of dark reddish-brown powder having the following repeating structural units (C2), (B1), and (C1). The following formulas, from left to right, represent the repeating structural units (C2), (B1), and (C1).

[0215]

[0216] Comparative Example 2 (Preparation of Copolymer)

[0217] (1) Manufacturing of intermediates

[0218] 7.58 g (34.4 mmol) of AdMA, 0.85 g (3.86 mmol) of DCPMA, 1.25 g (8.12 mmol) of MOI, and 0.25 g (1.52 mmol) of AIBN were dissolved in 20 mL of dehydrated toluene under an argon atmosphere. The resulting solution was added dropwise over 20 minutes to 20 mL of dehydrated toluene heated to 70 °C. The mixture was then stirred at 72–75 °C for 2 hours. After cooling to room temperature (approximately 23 °C), the resulting reaction mixture was added dropwise to 450 mL of dehydrated IPE to precipitate the polymer. The precipitate was filtered, washed successively with dehydrated IPE and dehydrated hexane, and then dried under reduced pressure at 70 °C to obtain 6.77 g of a white powder intermediate containing repeating structural units from AdMA, DCPMA, and MOI.

[0219] (2) Manufacturing of copolymers with nonlinear optically active sites

[0220] Under an argon atmosphere, 1.25 g of the above intermediate (1.05 mmol based on isocyanate groups), 0.557 g (0.806 mmol) of the nonlinear optically active compound [FTC-OH] prepared in Preparation Example 1, and approximately 100 mg of DBTDL were dissolved in 40 ml of dehydrated THF and stirred at 50–55 °C for 2 hours. Then, approximately 5 ml of methanol was added, and the mixture was stirred further at 50–55 °C for 1 hour. The resulting reaction mixture was precipitated with 500 ml of IPE, and the precipitate was filtered. The crude product obtained by washing with IPE:THF (10:1), followed by washing with IPE, and finally washing with MeOH was added to 100 ml of THF, heated to 60 °C to dissolve, dispersed in 1000 ml of IPE, and reprecipitated. The precipitate was filtered, washed with IPE:THF (10:1), then with IPE, and finally with MeOH. The mixture was then dried under reduced pressure at 70°C to obtain 1.49 g of a copolymer of dark reddish-brown powder containing the repeating structural units (C2), (C3), (B1), and (C1). The following formulas, from left to right, represent the repeating structural units (C2), (C3), (B1), and (C1).

[0221]

[0222] Next, the copolymers prepared in Examples 1-5, Comparative Examples 1 and 2 were used to perform various measurements and evaluations as described below. The results are shown in Tables 1 and 2.

[0223] (1) Determination of weight-average molecular weight

[0224] Device: HLC-8200GPC manufactured by Tosoh Corporation

[0225] Pillars: Shodex (registered trademark) GPC KF-804L + GPC KF-805L manufactured by Showa Denko Co., Ltd.

[0226] Column temperature: 40℃.

[0227] Solvent: THF

[0228] Detector: UV (254nm)

[0229] Standard curve: Standard polystyrene

[0230] (2) Determination of glass transition point (Tg)

[0231] Device: NETZSCH Photo-DSC 204 F1 Phoenix (registered trademark)

[0232] Measurement conditions: under nitrogen atmosphere

[0233] Heating rate: 30℃ / minute (-50~250℃)

[0234] (3) Viscosity determination

[0235] The viscosity of a solution of copolymer adjusted to a concentration of 20% by weight in cyclohexanone was measured using a viscometer (RHEOSENSE, HVROC-L).

[0236] (4) Evaluation of solubility

[0237] A solution of the copolymer, adjusted to a concentration of 20% by weight in cyclohexanone, was placed into a disposable plastic syringe fitted with a syringe filter (Acrodisc, 13mm, 0.2μm, PTFE) with a pore size of φ0.2μm, and the piston was pushed. The evaluation was then based on the tactile feedback when pushing the piston, according to the following criteria.

[0238] A: Holding the syringe filter with one hand, you can easily filter with almost no resistance by simply pushing the piston with the thumb of the hand holding the syringe filter (filtering can be easily done with one hand).

[0239] B: Although there is a slight resistance, it can be filtered without difficulty with one hand.

[0240] C: Although it can filter, there is a lot of resistance, making it difficult to push the piston with the thumb of the hand holding the syringe filter.

[0241] (5) Measurement of film thickness

[0242] Using a MIKASA 1H-DX2 spin coater, a solution of the copolymer in cyclohexanone at a concentration adjusted to 20% by weight was coated onto a cleaned substrate (quartz glass) in a specified amount. The coating was then vacuum-dried for 1 hour near the glass transition temperature (Tg) to produce both thin and thick films. The film thicknesses of the thin and thick films were measured using a stylus profilometer system (BRUKER, Dektak XT).

[0243] (6) Evaluation of cracks

[0244] The thin and thick films prepared above were observed for cracks using a stereomicroscope (Nikon Solutions, NIKON ECLIPSE L150) equipped with an eyepiece (×10) and an objective lens (×5).

[0245] (7) Determination of refractive index and electro-optic coefficient

[0246] Using a MIKASA 1H-DX2 spin coater, a solution of the copolymer in cyclohexanone at a concentration of 20% by weight was coated onto a cleaned substrate (quartz glass). The film was then vacuum-dried for 1 hour near its glass transition temperature (Tg) to produce a film approximately 3 μm thick. The refractive index of the film (wavelengths 1308 nm and 1532 nm) was measured using a Metricon 2010 / M prism coupler. Furthermore, the electro-optic coefficients of the film were measured using the same method described in the reference paper (“Transmission ellipsometric method without an aperture for simple and reliable evaluation of electro-optic properties”, Toshiki Yamada and Akira Otomo, Optics Express, vol. 21, pages 29240-48 (2013)). An Agilent Technologies DFB laser 81663A (wavelengths 1308 nm and 1550 nm) was used as the laser source.

[0247] [Table 1]

[0248]

[0249] [Table 2]

[0250]

[0251] As shown in Tables 1 and 2, it was confirmed that copolymers containing repeating structural units (A) with alkoxyadamantyl groups (Examples 1-5) could form crack-free films regardless of whether the film thickness was thin or thick. On the other hand, copolymers containing repeating structural units with adamantyl groups (Comparative Example 1) and copolymers containing repeating structural units with adamantyl groups and repeating structural units with dicyclopentyl groups (Comparative Example 2) produced cracks in films regardless of whether the film thickness was thin or thick. Furthermore, it was confirmed that films formed using the copolymers obtained in Examples 1-5 had a higher performance index (n) compared to films formed using the copolymers obtained in Comparative Examples 1 and 2. 3 High r) and excellent electro-optic effect.

[0252] Industrial availability

[0253] The copolymers of this invention are suitable for use as materials in electro-optical components such as optical switches, optical modulators, phase shifters, and terahertz wave generation and detection elements. Furthermore, in addition to applications in communication components, the copolymers of this invention can also be used in applications such as electric field sensors that detect changes in refractive index based on changes in the electric field. Moreover, in the fabrication processes of these components, film formation is frequently performed not only on flat surface structures but also on various uneven surface structures. Films on uneven surface structures are more prone to cracking due to the stress (strain) caused by the structure; therefore, the copolymers of this invention can expand the range of applications in electro-optical components.

Claims

1. A copolymer comprising: The repeating structural unit (A), represented by the following formula (1) and having an adamantyl alkyl group, and The repeating structural unit (B) has a nonlinear optically active site; （1）， In the formula, R 1 W represents a hydrogen atom or a methyl group. 1 Indicates -O-, -S-, or -NH-, L 1 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain single bonds, ether bonds, and / or ester bonds, or *-L. 2 -NHC(=O)O-, where, * indicates W 1 The bonding end, L 2 Ad represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds; Ad represents an adamantyl group that may be substituted by an alkyl group with 1 to 5 carbon atoms; R represents a divalent hydrocarbon group that may contain ether bonds and / or ester bonds. 2 The alkoxy group represents 1 to 10 carbon atoms bonded to any carbon atom constituting the adamantyl alkyl group, where n represents an integer from 1 to 15.

2. The copolymer according to claim 1, wherein, The repeating structural unit (B) includes repeating structural unit (B1) represented by the following formula (2-1) and / or repeating structural unit (B2) represented by the following formula (2-2). （2－1） （2－2）， In the formula, R 3 W represents a hydrogen atom or a methyl group. 2 Indicates -O-, -S-, or -NH-, L 3 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, or *-L. 4 -NHC(=O)O-, where * indicates that it is related to W 2 The bonding end, L 4 Z represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds, and Z represents an atomic group that exhibits nonlinear optical activity.

3. The copolymer according to claim 1, wherein, The content of the repeating structural unit (A) is 5-95 mol%, and the content of the repeating structural unit (B) is 5-95 mol%.

4. The copolymer according to claim 3, wherein, It further includes a repeating structural unit (C) with a structure different from that of the repeating structural unit (A) and the repeating structural unit (B), and the content of the repeating structural unit (C) is less than 90 mol%.

5. A composition comprising the copolymer of claim 1, and a solvent.

6. A nonlinear optical material comprising the copolymer of claim 1.

7. A nonlinear optical material comprising the copolymer of claim 1 and / or a polymer comprising repeating structural units (A) having adamantyl alkyl groups as represented by formula (1) and containing repeating structural units (B) having nonlinear optically active sites, and a nonlinear optically active compound. （1）， In the formula, R 1 W represents a hydrogen atom or a methyl group. 1 Indicates -O-, -S-, or -NH-, L 1 This indicates a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain single bonds, ether bonds, and / or ester bonds, or *-L. 2 -NHC(=O)O-, where, * indicates W 1 The bonding end, L 2 Ad represents a divalent hydrocarbon group with 1 to 30 carbon atoms that may contain ether bonds and / or ester bonds; Ad represents an adamantyl group that may be substituted by an alkyl group with 1 to 5 carbon atoms; R represents a divalent hydrocarbon group that may contain ether bonds and / or ester bonds. 2 The alkoxy group represents 1 to 10 carbon atoms bonded to any carbon atom constituting the adamantyl alkyl group, where n represents an integer from 1 to 15.

8. An electro-optical element comprising the copolymer of claim 1 or the nonlinear optical material of claim 6 or 7.

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