Dioxy compounds, curable compositions, cured products and optical members

Abstract

This invention provides a diepoxy compound with low water absorption in the cured product, a curable composition obtained using the above-mentioned diepoxy compound, a cured product, and an optical component. One aspect of this invention relates to a diepoxy compound represented by Formula 1 and Formula 2. In Formulas 1 and 2, any one of R... 1 For epoxy groups, the remaining R 1 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. R 2 R 3 R 4 The same applies.

Description

TECHNICAL FIELD

[0001] The present application relates to a diepoxy compound, a curable composition, a cured product, and an optical member. BACKGROUND

[0002] Epoxy compounds have been used in a wide range of applications.

[0003] Cured products obtained by polymerizing epoxy compounds are excellent in adhesion, heat resistance, mechanical properties, electrical properties, light resistance, and are easy to form. Among epoxy compounds, diepoxy compounds are expected to be applied to the field of optoelectronics such as electronic parts, optical parts, optical semiconductor sealing materials, optical part adhesives, and optical modeling materials (for example, Patent Documents 1 to 4, Non-Patent Document 1).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 11-343286

[0007] Patent Document 2: Japanese Patent No. 5000261

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 2004-285125

[0009] Patent Document 4: Chinese Patent No. 106916414

[0010] NON-PATENT DOCUMENTS

[0011] Non-Patent Document 1: Chemical Research in Toxicology (2019), 32(1), 57-66 SUMMARY

[0012] Patent Documents 1 and 2 disclose a diepoxy compound having a cyclohexane skeleton such as 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane, and the like as a diepoxy compound.

[0013] However, the diepoxy compounds of Patent Documents 1 and 2 are likely to be hydrolyzed under high temperature and high humidity because they contain ester bonds and ether bonds. In addition, because of high water absorption, the cured products are likely to be deformed due to swelling, and sometimes the properties required as optical parts, electronic parts, and the like are reduced.

[0014] Also known are diepoxy compounds that do not contain an ester bond or an ether bond. For example, Patent Document 3 discloses a diepoxy compound that is formed by bonding two 3,4-epoxycyclohexyl groups with a -CH2-, -C(CH3)2-, or the like. Non-Patent Document 1 discloses a diepoxy compound that is formed by bonding two cyclohexyl groups, each of which has a glycidyl group bonded to the 4-position carbon atom, with a -C(CH3)2-. Patent Document 4 discloses a diepoxy compound that is formed by bonding two cyclohexyl groups, each of which has an epoxy group bonded to the 4-position carbon atom, with a -CH2CH2CH(CH3)-.

[0015] However, even if a cured product is obtained using these diepoxy compounds, it can be difficult to sufficiently reduce the water absorption.

[0016] One embodiment of the present application is to provide a diepoxy compound that can obtain a cured product having a low water absorption, a curable composition obtained using the above diepoxy compound, a cured product, and an optical member.

[0017] The present application has the following modes.

[0018] [1] A diepoxy compound represented by the following formula 1.

[0019]

[0020] In formula 1, any one of R 1 is an epoxy group, and the remaining R 1 each independently is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms. Any one of R 2 is an epoxy group, and the remaining R 2 each independently is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

[0021] [2] The diepoxy compound according to [1], wherein the diepoxy compound is represented by the following formula 11.

[0022] a compound represented by formula 11,

[0023]

[0024] In formula 11, R 1 and R 2 each independently is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

[0025] [3] The diepoxy compound according to [1] or [2], wherein R 1 and R 2 each independently is a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.

[0026] [4] According to the diepoxide compound described in [1] or [2], wherein R is not an epoxy group. 1 and R 2 It consists entirely of hydrogen atoms.

[0027] [5] The following formula 2 represents a diepoxide compound.

[0028]

[0029] In Equation 2, any one R 3 For epoxy groups, the remaining R 3 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. Any one R 4 For epoxy groups, the remaining R 4 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. R 5 and R 6 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. R 5 and R 6 They can bond together to form a ring structure.

[0030] [6] According to the diepoxide compound described in [5], wherein the diepoxide compound is the following:

[0031] The compound represented by Formula 21.

[0032]

[0033] In Equation 21, R 3 and R 4 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

[0034] [7] According to [5] or [6], the diepoxide compound wherein R is not an epoxy group. 3 and R 4 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 6 carbon atoms; R 5 and R 6 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 6 carbon atoms.

[0035] [8] The diepoxide compound according to any one of [5] to [7], wherein R is not an epoxy group. 3 and R 4 It consists entirely of hydrogen atoms.

[0036] [9] According to the diepoxide compound described in [8], wherein R 5 and R 6 It is a methyl group.

[0037]

[10] A curable composition comprising the diepoxy compound according to any one of [1] to [9] and an initiator.

[0038]

[11] A cured product of the curable composition according to

[10] .

[0039]

[12] The cured product according to

[11] , wherein the water absorption rate when exposed to distilled water at 23°C for 24 hours is 0.45% or less.

[0040]

[13] An optical member composed of the cured product according to

[11] or

[12] .

[0041] According to one embodiment of the present application, there are provided a diepoxy compound that can provide a cured product having a low water absorption rate, a curable composition obtained using the above diepoxy compound, a cured product, and an optical member. DETAILED DESCRIPTION

[0042] The water absorption rate was measured by the method described in the examples.

[0043] The numerical range represented by "to" indicates a numerical range including the lower limit value and the upper limit value as the lower limit value and the upper limit value.

[0044] The numerical range of the content, the various physical property values, and the character values disclosed in the present specification can be combined arbitrarily into a new numerical range from the lower limit value and the upper limit value.

[0045] [Diepoxy compound]

[0046] The diepoxy compound according to the first embodiment of the present application is a compound represented by the following formula 1 (hereinafter, also referred to as "compound A").

[0047]

[0048] In formula 1, any one of R 1 is an epoxy group, and the remaining R 1 is independently a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms. In addition, any one of R 2 is an epoxy group, and the remaining R 2 is independently a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

[0049] R 1 The epoxy group of R 1 may be bonded to any one of the carbon atoms in the cyclohexane ring to which a plurality of R 1 is bonded. From the viewpoint of ease of production, the epoxy group of R 1 is preferably bonded to the 4-position carbon atom of the cyclohexane ring to which a plurality of R

[0050] the plurality of R 1 may be the same group or different groups. As the R 1 from the viewpoint of water absorption, a hydrogen atom, or a linear or branched alkyl group having 1 to 6 carbon atoms is preferred, and a hydrogen atom is particularly preferred.

[0051] R 2 may be bonded to any of the carbon atoms in the cyclohexane ring to which the plurality of R 2 may be bonded. From the viewpoint of ease of production, the epoxy group of R 2 is preferably bonded to the 4-position carbon atom of the cyclohexane ring to which the plurality of R 2 may be bonded.

[0052] the plurality of R 2 may be the same group or different groups. The R 2 that is not an epoxy group can be the same group as the R 1 that is not an epoxy group, or a different group. As the R 2 that is not an epoxy group, a hydrogen atom, or a linear or branched alkyl group having 1 to 6 carbon atoms is preferred from the viewpoint of water absorption, and a hydrogen atom is particularly preferred.

[0053] from the viewpoint of water absorption, a hydrogen atom, or a linear or branched alkyl group having 1 to 6 carbon atoms is preferred, and a hydrogen atom is particularly preferred.

[0054]

[0055] In formula 11, R 1 and R 2 are each independently a hydrogen atom, or a linear or branched alkyl group having 1 to 10 carbon atoms.

[0056] The preferred modes of R 1 and R 2 in formula 11 above are the same as the preferred modes of the R 1 and R 2 that are not epoxy groups in formula 1 above.

[0057] from the viewpoint of ease of production, a compound in which R 1 and R 2 in formula 11 above are each a hydrogen atom, i.e., a compound represented by the following formula 12 (hereinafter, also referred to as “compound A1-1”), is particularly preferred as the compound A1.

[0058]

[0059] There are no particular limitations on the synthesis method of compound A. Compound A can be synthesized by appropriately combining various reactions. For example, when using a compound in which two epoxy groups are replaced with hydroxyl groups as the starting material, the starting material is reacted with a silylating agent (such as tert-butyldimethylchlorosilane) to replace the two hydroxyl groups with silyl groups to form a dimethylsilyl body. Next, the dimethylsilyl body is reacted with a halide (such as boron tribromide) to replace the two silyl groups with halogen atoms through desilylation and halogenation to form a dihalide. Subsequently, in the presence of a copper catalyst (such as CuCl2), the dihalide is subjected to a cross-coupling reaction with vinyl magnesium bromide, followed by reaction with a peroxide (such as m-chloroperoxybenzoic acid) to epoxidize the vinyl group, thereby obtaining compound A.

[0060] The solvent used in the synthesis of compound A can be appropriately selected as long as it does not adversely affect the reactions. Examples include dimethylformamide, dichloromethane, tetrahydrofuran, halogenated hydrocarbons (such as dichloromethane), ethers (such as diethyl ether and tetrahydrofuran), aromatic hydrocarbons (such as benzene and toluene), aliphatic hydrocarbons (such as hexane and pentane), and amide solvents (such as N,N-dimethylformamide and N-methylpyrrolidone).

[0061] The diepoxide compound of the second aspect of the present invention is a compound represented by Formula 2 (hereinafter also referred to as "Compound B").

[0062]

[0063] In Equation 2, any one R 3 For epoxy groups, the remaining R 3 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. Additionally, any one R... 4 For epoxy groups, the remaining R 4 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms.

[0064] R 5 and R 6 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. R 5 and R 6 They can bond together to form a ring structure.

[0065] R 3 The epoxy group can be bonded to multiple R groups. 3 It is bonded to any carbon atom in the cyclohexane ring. For ease of manufacture, R... 3 The epoxy group is preferably bonded to a group having multiple R groups. 3 The carbon atom at position 4 of the cyclohexane ring.

[0066] Multiple Rs that are not epoxy groups3 They can be the same group or different groups. R, which is not an epoxy group, 3 From the perspective of water absorption rate, hydrogen atoms or straight-chain or branched alkyl groups with 1 to 6 carbon atoms are preferred, and hydrogen atoms are particularly preferred.

[0067] R 4 The epoxy group can be bonded to multiple R groups. 4 It is bonded to any carbon atom in the cyclohexane ring. For ease of manufacture, R... 4 The epoxy group is preferably bonded to a group having multiple R groups. 4 The carbon atom at position 4 of the cyclohexane ring.

[0068] Multiple Rs that are not epoxy groups 4 They can be the same group or different groups. R that is not an epoxy group... 4 It can be R that is not an epoxy group 3 The same group can also be different groups. As for R, which is not an epoxy group... 4 From the perspective of water absorption rate, hydrogen atoms or straight-chain or branched alkyl groups with 1 to 6 carbon atoms are preferred, and hydrogen atoms are particularly preferred.

[0069] R 5 and R 6 It can be the same group or different groups. R 5 and R 6 When forming a ring structure, it is a cycloalkyl group. R 5 and R 6 When forming a ring structure, cycloalkyl groups with 5 to 12 carbon atoms are preferred, and cycloalkyl groups with 6 or fewer carbon atoms are more preferred. 5 and R 6 The resulting ring structure can be a single-ring structure or a multi-ring structure.

[0070] Based on ease of manufacturing, R 5 and R 6 Each of the following is preferred independently: a hydrogen atom or a straight-chain or branched alkyl group having 1 to 6 carbon atoms; methyl or ethyl is further preferred; and methyl is particularly preferred.

[0071] From the perspective of water absorption rate, the compound represented by the following formula 21 (hereinafter also referred to as "compound B1") is preferred as compound B.

[0072]

[0073] In Equation 21, R 3 and R 4 Each is independently a hydrogen atom or a straight-chain or branched alkyl group having 1 to 10 carbon atoms. R 5 and R 6The same as the above Formula 2.

[0074] R in the above Formula 21 3 ~R 6 The preferable mode of R 3 and R 4 in the above Formula 2 is the same as the preferable mode of R 5 , R 6 in the above Formula 2.

[0075] As the compound B1, for example, a compound represented by the following Formula 22 (hereinafter, also described as "compound B1-1") can be exemplified. As R 5 and R 6 form a ring structure, for example, a compound represented by the following Formula 23, a compound represented by the following Formula 24 can be exemplified.

[0076]

[0077] From the viewpoint of ease of manufacture, as the compound B1, a compound in which R 3 and R 4 in the above Formula 21 are all hydrogen atoms, and R 5 and R 6 are methyl groups, that is, the compound B1-1, is particularly preferable.

[0078] The synthesis method of the compound B is not particularly limited. The compound B can be synthesized by appropriately combining various reactions. For example, a compound in which 2 epoxy groups in the compound B are substituted with hydroxyl groups is used as a starting material, and in addition thereto, the compound B can be synthesized by using the same method as the method exemplified as the synthesis method of the compound A.

[0079] [Curable composition]

[0080] The curable composition of the present application contains the diepoxy compound of the present application and an initiator. The curable composition of the present application is cured by light irradiation, heating, or the like according to the kind of the initiator, whereby a cured product is obtained.

[0081] The curable composition of the present application can contain either one of the compound A and the compound B as the diepoxy compound, or both of them as the diepoxy compound. The compound A contained in the curable composition can be one kind, or two or more kinds. The compound B contained in the curable composition can be one kind, or two or more kinds.

[0082] The curable composition of the present application can contain, as the resin component, an epoxy compound, an oxetane compound, or the like other than the compound A and the compound B, as long as the effect of the present application is not impaired.

[0083] As the oxetane compound, various monofunctional oxetane compounds, polyfunctional oxetane compounds can be exemplified. As the monofunctional oxetane compound, for example, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane can be exemplified. As the polyfunctional oxetane compound, for example, 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane can be exemplified.

[0084] As the other epoxy compound, for example, 2,2-bis[4-(2,3-epoxypropyloxy)cyclohexyl]propane can be exemplified.

[0085] The other resin component than the compound A and the compound B included in the curable composition can be one or two or more.

[0086] As the initiator that initiates the curing of the curable composition of the present application, there is no particular limitation. For example, an initiator that generates a cationic species by light irradiation or heating can be exemplified. The initiator included in the curable composition can be one or two or more.

[0087] The initiator that generates a cationic species by light irradiation is not particularly limited. For example, a UV cationic polymerization initiator that generates an acid that can undergo cationic polymerization by UV irradiation can be exemplified.

[0088] The UV cationic polymerization initiator generates an acid that can undergo cationic polymerization by UV irradiation. For example, a diazonium salt-based compound, an iodonium salt-based compound, a sulfonium salt-based compound, a phosphonium salt-based compound, a selenonium salt-based compound, an oxonium salt-based compound, an ammonium salt-based compound, a bromonium salt-based compound, and the like can be exemplified.

[0089] As the anion component of the UV cationic polymerization initiator, for example, SbF6 － , PF6 － , BF4 － , AsF6 － , B(C6F5)4 － can be exemplified. From the aspect of curability, it is preferable to contain B(C6F5)4 － , PF6 － , or SbF6 － as the anion component. It is more preferable to contain B(C6F5)4 － as the anion component of the aromatic sulfonium salt or the like onium salt. The UV cationic polymerization initiator included in the curable resin composition can be one or two or more.

[0090] The curable composition of the present application can further contain an additive as needed. As the additive, for example, a coupling agent (silane-based coupling agent, titanium-based coupling agent, etc.), a flexibility imparting agent (synthetic rubber, polyorganosiloxane, etc.), an antioxidant, an antifoaming agent, a hydrocarbon-based wax, an inorganic filler, etc. can be exemplified.

[0091] The total content of Compound A and Compound B in the curable composition of the present application, relative to the total mass of the resin component in the curable composition, is preferably 50 to 100 mass%, more preferably 60 to 100 mass%. If the total content of Compound A and Compound B is the lower limit value of the above range or more, the water absorption of the cured product becomes low, and deformation due to swelling is unlikely even under a high-temperature high-humidity environment.

[0092] The content of the initiator in the curable composition of the present application, relative to 100 parts by mass of the resin component in the curable composition, is preferably 0.1 to 2.0 parts by mass, more preferably 0.2 to 1.0 parts by mass. If the content of the initiator is the lower limit value of the above range or more, the curability is excellent. If the content of the initiator is the upper limit value of the above range or less, coloring of the cured product is easily suppressed.

[0093] [Cured product]

[0094] The cured product of the present application is a cured product of the curable composition of the present application. The shape and size of the cured product are not particularly limited, and can be appropriately set according to the use.

[0095] The use of the cured product of the present application is not particularly limited. For example, electronic parts, optical parts, optical semiconductor sealing materials, optical part adhesives, and optical molding materials can be exemplified. Among them, the cured product of the present application is useful as an optical part from the viewpoint of low water absorption and unlikely deformation.

[0096] The water absorption of the cured product of the present application when exposed to distilled water at 23°C for 24 hours is preferably 0.45% or less, more preferably 0.40% or less, and further preferably 0.35% or less. If the water absorption is the upper limit value or less, deformation due to swelling is unlikely even under a high-temperature high-humidity environment, and the properties required for optical parts, electronic parts, etc. are unlikely to decrease. The lower the water absorption of the cured product, the better, and the practical lower limit is around 0.10%.

[0097] According to the above description, in the present application, a cured product with low water absorption is obtained by using Compound A and Compound B as diepoxide compounds. Therefore, the cured product is unlikely to deform due to swelling, and the properties required for optical parts, electronic parts, etc. are unlikely to decrease. In addition, since Compound A and Compound B do not contain an ester bond or an ether bond, hydrolysis is not generated even under a high-temperature high-humidity environment, and the durability is excellent.

[0098] Example

[0099] Hereinafter, the present application will be specifically described according to Examples, but the present application is not limited by the following description. Examples 1 and 2 are examples. Examples 3 to 6 are comparative examples.

[0100] [Synthesis Example 1]

[0101] The compound B1-1 was synthesized in the following order.

[0102] The reaction shown in the following formula 3 was performed. 2,2-bis(4-hydroxycyclohexyl)propane (30 g, 128.9 mmol) was dissolved in dimethylformamide (DMF, 500 mL), and further, imidazole (38.3 g, 562 mmol) and tert-butyldimethylsilyl chloride (TBDMSCl, 84.7 g, 562 mmol) were added at 0°C, and stirred at room temperature overnight under nitrogen atmosphere. After the completion of the reaction, a mixed solvent of ethyl acetate / hexane = 1 / 4 and water were added to extract the reaction product. Then, water was washed twice, and the solvent was removed to obtain a white solid of a silyl body (58.3 g).

[0103] The silyl body (42.4 g) was dissolved in dichloromethane (480 mL), and a 1M dichloromethane solution of boron tribromide (275 mL) was added dropwise at 0°C, and after the completion of the dropwise addition, the reaction was performed overnight at room temperature. After the completion of the reaction, the reaction solution was added to a saturated aqueous sodium bicarbonate solution, and after stirring for 10 minutes, extraction was performed. Then, water was washed twice, and the solvent was removed, and a transparent oily dibromide (30.0 g, 82.4 mmol) was separated by flash column chromatography (5% ethyl acetate / hexane solution).

[0104] The overall yield of the reaction of formula 3 was 88.3%.

[0105]

[0106] Hereinafter, the reaction shown in the following formula 4 was performed.

[0107] The dibromide (30 g, 82.4 mmol) was dissolved in tetrahydrofuran (THF, 180 mL), and acetylene benzene (0.93 g, 8.2 mmol) and CuCl2(2.2 g, 16.4 mmol) were added at 0°C, and a 1M THF solution of vinylmagnesium bromide (300 mL) was added dropwise at 0°C under nitrogen atmosphere. After the completion of the dropwise addition, stirring was performed overnight at room temperature, and then, a 10% hydrochloric acid solution was added to complete the reaction, and the reaction product was extracted with ethyl acetate. Then, water was washed twice, and the solvent was removed, and a transparent oily diene (15.1 g, 58.0 mmol, 70.4%) was separated by flash column chromatography (5% ethyl acetate / hexane solution).

[0108]

[0109] The reaction shown in the following formula 5 was performed. The diene (15.1 g, 58.0 mmol) was dissolved in dichloromethane (330 ml), and m-chloroperoxybenzoic acid (61.6 g, 232.0 mmol) was added at 0°C, and stirred at room temperature overnight. The reaction solution was added to saturated aqueous sodium sulfite solution to terminate the reaction, and the reaction was extracted. Then, it was washed with water twice, and the solvent was removed, and the compound (Bl-1) (4.5 g, 15.4 mmol, 26.6%) was isolated as a transparent oil by flash column chromatography (ethyl acetate / hexane = 1 / 6 solution).

[0110] The NMR spectrum of the compound (Bl-1) is shown below.

[0111] 1 H-NMR (400 MHz, solvent: CDC13, reference: tetramethylsilane (TMS)) δ (ppm): 3.11-2.50 (m, 6H), 1.99-1.96 (m, 2H), 1.76-1.73 (m, 5H), 1.58-1.55 (m, 2H), 1.34-1.00 (m, 11H), 0.76-0.71 (m, 6H)

[0112]

[0113] [Synthesis Example 2]

[0114] The compound Al-1 was synthesized in the following order.

[0115] The reaction shown in the following formula 6 was performed. The 4,4-biscyclohexanol (50 g, 252.1 mmol) was dissolved in DMF (500 ml), and further, imidazole (41.0 g, 602.2 mmol) and TBDMSCl (92.0 g, 610.4 mmol) were added at 0°C, and stirred at room temperature overnight under nitrogen atmosphere. After the reaction was terminated, a mixed solvent of ethyl acetate / hexane = 1 / 4 and water were added, and the reaction was extracted. Then, it was washed with water twice, and the solvent was removed, and a white solid of the silyl body (70.34 g) was obtained.

[0116] The silyl body (70.34 g) was dissolved in dichloromethane (600 ml), and a 1M dichloromethane solution of boron tribromide (400 ml) was added dropwise at 0°C, and after the addition was terminated, the reaction was performed at room temperature overnight. After the reaction was terminated, the reaction solution was added to saturated aqueous sodium bicarbonate solution, and stirred for 10 minutes, and then the reaction was extracted. Then, it was washed with water twice, and the solvent was removed, and the dibromide (57.0 g, 177.1 mmol) was isolated as a transparent oil by flash column chromatography (5% ethyl acetate / hexane solution).

[0117] The total yield of the reaction of Formula 6 was 70.2%.

[0118]

[0119] The reaction shown in Formula 7 was performed. The dibromide (29.1 g, 90.3 mmol) was dissolved in THF (180 mL), acetylenebenzene (1.1 g, 9.0 mmol) and CuCl2(2.4 g, 18.1 mmol) were added at 0°C, and a 1M THF solution of vinylmagnesium bromide (270 mL) was added dropwise at 0°C under a nitrogen atmosphere. After the dropwise addition was completed, stirring was performed at room temperature overnight, 10% hydrochloric acid solution was added to terminate the reaction, and the reaction was extracted with ethyl acetate. Subsequently, it was washed twice with water, the solvent was removed, and the diene (11.0 g, 50.6 mmol, 56.0%) was isolated as a transparent oil by flash column chromatography (5% ethyl acetate / hexane solution).

[0120]

[0121] The reaction shown in Formula 8 was performed. The diene (21.6 g, 98.9 mmol) was dissolved in dichloromethane (400 mL), m-chloroperoxybenzoic acid (105.0 g, 395.6 mmol) was added at 0°C, and stirring was performed at room temperature overnight. The reaction solution was added to saturated aqueous sodium sulfite solution to terminate the reaction, and the reaction was extracted. Subsequently, it was washed with water, the solvent was removed, and compound A1-1 (5.5 g, 21.8 mmol, 22.0%) was isolated as a transparent oil by flash column chromatography (ethyl acetate / hexane = 1 / 6 solution).

[0122] The NMR spectrum of compound (A1-1) is shown below.

[0123] 1 H-NMR (400 MHz, solvent: CDC13, reference: TMS) δ (ppm): 2.96-2.46 (m, 6H), 1.94-0.88 (m, 20H)

[0124]

[0125] [Example 1]

[0126] A curable composition was prepared by adding 0.5 parts by mass of an ultraviolet cationic polymerization initiator (Irgacure 2959, manufactured by BASF Corporation) with respect to 100 parts by mass of the compound B1-1 obtained in Synthesis Example 1.

[0127] Two round plate-shaped glass substrates, which were subjected to the release treatment, were prepared. One of the glass substrates was arranged in parallel to the other glass substrate with a gap of 1.0 mm between the glass substrates. The curable composition was flowed between the two glass substrates without air bubbles. Next, the curable composition in a state of being sandwiched by the two glass substrates was subjected to ultraviolet irradiation at an exposure dose of 4500 mJ / cm 2 After the ultraviolet irradiation (using an LED lamp with a wavelength of 365 nm), the cured product was heated at 180°C for 3 hours under a nitrogen atmosphere to produce an evaluation sample.

[0128] [Example 2]

[0129] An evaluation sample was obtained in the same manner as in Example 1, except that the compound Al-1 obtained in Synthesis Example 2 was used instead of the compound Bl-1. Specifically, the curable composition was prepared using the compound Al-1, and then the cured product was produced as an evaluation sample under the same conditions as in Example 1.

[0130] [Example 3]

[0131] A curable composition was prepared in the same manner as in Example 1, except that 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (CEL-2021P, manufactured by Dainippon Ink and Chemicals, Incorporated) was used instead of the compound Bl-1. Using the above curable composition, an evaluation sample was produced in the same manner as in Example 1, except that the ultraviolet irradiation was performed using an LED lamp with a wavelength of 365 nm at an exposure dose of 9000 mJ / cm 2 After the ultraviolet irradiation, the cured product was not left to stand at room temperature, but was changed to a curing condition of heating at 60°C for 5 minutes and heating at 80°C for 5 minutes, and then an evaluation sample was produced in the same manner as in Example 1.

[0132] [Example 4]

[0133] A curable composition was prepared in the same manner as in Example 1, except that 2,2-bis[4-(2,3-epoxypropyloxy)cyclohexyl]propane (YX-8000, manufactured by Mitsubishi Chemical Corporation) was used instead of the compound Bl-1. Using the above curable composition, an evaluation sample was produced in the same manner as in Example 1, except that the cured product was not left to stand at room temperature after the ultraviolet irradiation.

[0134] [Example 5]

[0135] An evaluation sample was obtained in the same manner as in Example 4, except that a compound C-1 represented by the following formula C-1 was used instead of the compound Bl-1. Specifically, the curable composition was prepared using the compound C-1, and then the cured product was produced as an evaluation sample under the same conditions as in Example 4.

[0136]

[0137] [Example 6]

[0138] An evaluation sample was obtained in the same manner as in Example 4, except that a compound C-2 represented by the following formula C-2 was used instead of the compound B1-1. Specifically, a curable composition was prepared using the compound C-2, and then a cured product was produced under the same conditions as in Example 4 as an evaluation sample.

[0139]

[0140] [Water absorption]

[0141] The evaluation sample of each example was dried under reduced pressure, and the evaluation sample after the reduced-pressure drying was weighed, and the weighed value was set as W A . In addition, the evaluation sample was weighed again after the evaluation sample was exposed to distilled water at 23°C for 24 hours, and the weighed value was set as W B . The water absorption was calculated from the following formula using these weighed values. The water absorption was measured for 3 to 5 evaluation samples under the same conditions, and the average value thereof was taken as the water absorption of the cured product of each example. The evaluation results of each example are shown in Table 1.

[0142] Water absorption (%) = ((W B -W A ) / W A ) x 100

[0143] [Table 1]

[0144] Diepoxide compound Water absorption [%] Example 1 B1-1 0.15 Example 2 A1-1 0.27 Example 3 CEL-2021P 1.45 Example 4 YX-8000 0.52 Example 5 C-1 0.51 Example 6 C-2 0.53

[0145] As shown in Table 1, the cured products of Examples 1 and 2 had lower water absorption than the cured products of Examples 3 to 6.

[0146] Industrial applicability

[0147] According to one embodiment of the present application, a diepoxy compound from which a cured product having low water absorption can be obtained, a curable composition obtained using the above-described diepoxy compound, a cured product, and an optical member are provided.

[0148] In addition, this application claims priority based on Japanese Patent Application No. 2020-210133 filed on December 18, 2020, and the entire contents of this Japanese application are incorporated herein by reference.

Claims

1. A diepoxy compound represented by the following formula 1, In Formula 1, any one R 1 is an epoxy group, and the remaining R 1 are each independently a hydrogen atom, or a linear or branched alkyl group having 1 to 10 carbon atoms. Any one R 2 is an epoxy group, and the remaining R 2 are each independently a hydrogen atom, or a linear or branched alkyl group having 1 to 10 carbon atoms.

2. The diepoxy compound according to claim 1, wherein, The diepoxy compound is a compound represented by the following formula 11, In formula 11, R 1 and R 2 each independently is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

3. The diepoxy compound according to claim 1 or 2, wherein, R is not an epoxy group 1 R is not an epoxy group 2 each independently is a hydrogen atom, or a linear or branched alkyl group having 1 to 6 carbon atoms.

4. The diepoxy compound according to claim 1 or 2, wherein, R is not an epoxy group 1 and R 2 are all hydrogen atoms.

5. A diepoxy compound represented by the following formula 2, In formula 2, any one of R 3 is an epoxy group, and the remaining R 3 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, any one of R 4 is an epoxy group, and the remaining R 4 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, R 5 and R 6 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, R 5 and R 6 may be bonded to each other to form a ring structure.

6. The diepoxy compound of claim 5, wherein, The diepoxy compound is a compound represented by the following formula 21, In formula 21, R 3 and R 4 each independently is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

7. The diepoxy compound according to claim 5 or 6, wherein, R is not an epoxy group 3 R is not an epoxy group 4 each independently is a hydrogen atom, or a linear or branched alkyl group having 1 to 6 carbon atoms, R 5 and R 6 each independently is a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.

8. The diepoxy compound according to claim 5 or 6, wherein, R is not an epoxy group 3 R is not an epoxy group 4 are all hydrogen atoms.

9. The diepoxy compound of claim 7, wherein, R is not an epoxy group 3 and R 4 are all hydrogen atoms.

10. The diepoxy compound of claim 8, wherein, R 5 and R 6 is methyl.

11. The diepoxy compound of claim 9, wherein, R 5 and R 6 is methyl.

12. A curable composition comprising the diepoxy compound according to any one of claims 1 to 11 and an initiator.

13. A cured product of the curable composition according to claim 12.

14. The cured product according to claim 13, wherein, The water absorption rate when exposed to distilled water at 23°C for 24 hours is 0.45% or less.

15. An optical member composed of the cured product according to claim 13 or 14.

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