Cyclic carbonate and its manufacturing method

Abstract

To provide a cyclic carbonate having excellent heat resistance, a use thereof, and a method for producing the same.SOLUTION: A cyclic carbonate is represented by the following formula (1) (where, in the formula (1), R1, R2, R3, R4 independently represent a hydrogen atom, a hydroxy group, a phosphate group, an aryl group, an aralkyl group, an alkoxy group, a silyl group, a silyl alkoxy group, an ester group, an acyl group, or an unsubstituted linear, branched, or cyclic alkyl group, or R1-R4 may form a cyclic structure together with a carbon element to which they are bound, and n is an integer of 0 or 1).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to cyclic carbonates. [Background technology]

[0002] Cyclic carbonates are used for various purposes, such as electrolytes for lithium ion secondary batteries, various synthetic intermediates, and polymer raw materials. For example, ethylene carbonate, the simplest five-membered cyclic carbonate, is known as a highly polar solvent and is used as electrolytes for lithium ion secondary batteries because of its excellent dielectric constant (Patent Document 1). In addition, polymers obtained by ring-opening polymerization of trimethylene carbonate, which has a six-membered cyclic carbonate structure, are biodegradable and therefore are used as biocompatible materials (Patent Document 2).

[0003] Thus, cyclic carbonates are used as useful compounds and intermediates, but as described in Non-Patent Document 1, when ethylene carbonate is used as an electrolyte for batteries, oxidative decomposition of the electrolyte occurs and causes deterioration of the battery when used at high temperatures or high voltages. According to the "AEC-Q200" standard for high temperature and humidity resistance, heat resistance, impact resistance, durability, etc. formulated by the Automotive Electronics Council (AEC), the operating temperature range of the lowest grade Grade 4 is 0°C to 70°C, while Grade 3 is -40°C to 85°C, Grade 2 is -40°C to 105°C, Grade 1 is -40°C to 125°C, and the highest grade Grade 0 is -50°C to 150°C. Durability is particularly required at high temperatures, and it is thought that chemical stability at these temperatures will also be required for electrolytes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-48135 [Patent Document 2] JP 2012-232909 A [Non-patent literature]

[0005] [Non-Patent Document 1] Journal of the Electrochemical Society 2014, 161, A1777. Summary of the Invention [Problem to be solved by the invention]

[0006] Ethylene carbonate, which is used as an electrolyte for lithium-ion secondary batteries, has a melting point of 37 to 39°C, and when heated to 150°C in a nitrogen atmosphere, a mass loss of about 20% was confirmed. Cyclohexene carbonate, an alicyclic carbonate with relatively excellent heat resistance, also has a melting point of about 58 to 60°C, and when heated in a nitrogen atmosphere, a mass loss of about 8% was confirmed at 150°C and about 58% at 200°C, indicating that its heat resistance is insufficient.

[0007] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a cyclic carbonate having excellent heat resistance, and a method for producing the same. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the inventors synthesized cyclic carbonates having a specific cyclic structure in their skeleton and discovered that they have excellent heat resistance, thereby completing the present invention.

[0009] That is, the present invention is as follows. [1] The following formula (1): [ka] (In formula (1), R 1 , R 2 , R 3 , and R 4are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; R 1 ~R 4 may form a ring structure together with the carbon atom to which they are attached, and in the ring structure, R 1 ~R 4 are bonded to each other via an alkylene group or a carbonate group, the alkylene group may be substituted with a hydroxyl group, a phosphate group, an alkoxy group having 1 to 10 carbon atoms, an ester group having 1 to 10 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; n is an integer of 0 or 1. A cyclic carbonate represented by the formula: [2] The following formula (2): [ka] (In formula (2), R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. A cyclic carbonate represented by the formula: [3] The following formula (3): [ka] (In formula (3), R 1 , R2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. A cyclic carbonate represented by the formula: [4] The following formula (4): [ka] The cyclic carbonate according to [1] or [2], represented by the formula: [5] The following formula (5): [ka] The cyclic carbonate according to [1] or [3], represented by the formula: [6] A method for producing a cyclic carbonate according to any one of [1] to [5], The following formula (6): [ka] The epoxide represented by the formula (7): [ka] and a step of reacting the diol compound with a halogenated formate ester or a carbonate ester to obtain a cyclic carbonate; A manufacturing method comprising: (In formulas (6) and (7), R 1 , R 2 , R 3 , and R4 are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; R 1 ~R 4 may form a ring structure together with the carbon atom to which they are attached, and in the ring structure, R 1 ~R 4 are bonded to each other via an alkylene group or a carbonate group, the alkylene group may be substituted with a hydroxyl group, a phosphate group, an alkoxy group having 1 to 10 carbon atoms, an ester group having 1 to 10 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; n is an integer of 0 or 1. Effect of the Invention

[0010] According to the present invention, a cyclic carbonate having excellent heat resistance can be provided. [Brief description of the drawings]

[0011] [Figure 1] 1 shows the 1H-NMR spectrum of the cyclic carbonate in Example 1. [Diagram 2] 1 shows the 13C-NMR spectrum of the cyclic carbonate in Example 1. [Diagram 3] 1 shows the 1H-NMR spectrum of the cyclic carbonate in Example 2. [Figure 4] 1 shows the 13C-NMR spectrum of the cyclic carbonate in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention (hereinafter, also referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the present embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0013] <Cyclic carbonate> The cyclic carbonate of the present embodiment has a structure represented by the following formula (1).

[0014] [ka]

[0015] In formula (1), R 1 , R 2 , R 3 , R 4 are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, or R 1 ~R 4 may form a ring structure together with the carbon atom to which they are attached, and in the ring structure, R 1 ~R 4 are bonded to each other via an alkylene group or a carbonate group, and the alkylene group may be substituted with a hydroxyl group, a phosphate group, an alkoxy group having 1 to 10 carbon atoms, an ester group having 1 to 10 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Also, n is an integer of 0 or 1. In this specification, the term "carbonate group" refers to a divalent substituent represented by -OC(=O)O-.

[0016] The cyclic carbonate of the present embodiment has the above-mentioned configuration and is therefore excellent in heat resistance, which is believed to be due to, but not limited to, the following reasons.

[0017] Conventional cyclic carbonates having an alicyclic structure have a cyclic skeleton, but the structural freedom of the cycloalkane skeleton is relatively high, and the structure results in low heat resistance. In contrast, the cyclic carbonate of the present embodiment has a bicyclic structure in which the 1,4-positions of cyclohexane are crosslinked with C1 or C2 alkyl chains, and the skeleton is rigid, so it is presumed that the cyclic carbonate has excellent heat resistance.

[0018] In this embodiment, in formula (1), R 1 ~R 4 are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. 1 ~R 4 are preferably each independently one or more substituents selected from the group consisting of a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, and an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. 1 ~R 4 More preferably, each independently represents one or more substituents selected from the group consisting of a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, and an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. 1 ~R 4 More preferably, each independently represents one or more substituents selected from the group consisting of a hydrogen atom, an alkoxy group having 1 to 10 carbon atoms, and an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms.

[0019] In this embodiment, in formula (1), R 1 ~R 4may be bonded to each other via an alkylene group or a carbonate group (-OC(=O)O- group) to form a cyclic structure, and the alkylene group may be substituted with a hydroxyl group, a phosphate group, an alkoxy group, or an ester group. From the viewpoint of more reliably and effectively achieving the effects of the present invention, R 1 ~R 4 When R are bonded to each other via an alkylene group to form a cyclic structure, the number of carbon atoms in the alkylene group is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 12. From the same viewpoint, the substituent of the alkylene group is preferably a hydroxyl group, an alkoxy group, or an ester group, and more preferably a hydroxyl group or an alkoxy group. From the same viewpoint, R 1 ~R 4 When the ring structure is formed, the ring structure is preferably formed via an unsubstituted alkylene group. Examples of the unsubstituted alkylene group include a methylene group, an ethylene group, a 1,3-propylene group, a 1,4-butylene group, a 1,5-pentylene group, a 1,3-cyclopentylene group, a 1,6-hexylene group, a 1,3-cyclohexylene group, and a 1,4-cyclohexylene group.

[0020] R 1 ~R 4 When R forms a ring structure, 1 ~R 4 It is preferable that any two of the above forms a cyclic structure. Examples of the combination that forms a cyclic structure include R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 1 and R 3 , R 2 and R 4 , or R 1 and R 4 Examples include:

[0021] The phosphate group in the above formula (1) of this embodiment may be unsubstituted or substituted. That is, it may be a mono-substituted phosphate group or a di-substituted phosphate group. From the viewpoint of more effectively and reliably achieving the effects of the present invention, when the phosphate group is substituted, the substituent is preferably an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. From the same viewpoint, the phosphate group in this embodiment is preferably unsubstituted.

[0022] The aryl group having 6 to 20 carbon atoms in the above formula (1) of this embodiment is not particularly limited, and examples thereof include unsubstituted or alkyl-containing aryl groups such as a phenyl group, a methylphenyl group, a dimethylphenyl group, a trimethylphenyl group, a tetramethylphenyl group, a pentamethylphenyl group, an ethylphenyl group, a propylphenyl group, and a diisopropylphenyl group; alkoxy-containing aryl groups such as a 4-methoxyphenyl group and a 3,5-dimethoxyphenyl group; and biphenyl, naphthyl, and anthracenyl groups.

[0023] The aralkyl group having 6 to 20 carbon atoms in the above formula (1) of the present embodiment is not particularly limited, and examples thereof include unsubstituted or alkyl group-containing aralkyl groups such as benzyl group, 4-methylbenzyl group, and phenethyl group, alkoxy group-containing aralkyl groups such as 4-methoxybenzyl group and 3,5-dimethoxybenzyl group, and diphenylmethyl group, naphthylmethyl group, and anthracenylmethyl group.

[0024] The alkoxy group having 1 to 10 carbon atoms in the above formula (1) of the present embodiment is not particularly limited, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a cyclopentyloxy group, a hexyloxy group, a cyclohexyloxy group, a heptyloxy group, an octyloxy group, a nonanyloxy group, a decyloxy group, a phenoxy group, a benzyloxy group, a vinyloxy group, and an allyloxy group.

[0025] The silyl group having 1 to 30 carbon atoms in the above formula (1) of the present embodiment is not particularly limited, and examples thereof include a trimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a triphenylsilyl group, a tert-butyldimethylsilyl group, a di-tert-butylisobutylsilyl group, and a tert-butyldiphenylsilyl group.

[0026] The silylalkoxy group having 1 to 30 carbon atoms in the above formula (1) of this embodiment is not particularly limited, and examples thereof include a trimethylsilylmethoxy group, a trimethylsilylethoxy group, a trimethylsilylphenoxy group, a trimethylsilylbenzyloxy group, a triethylsilylmethoxy group, a triethylsilylethoxy group, a triethylsilylphenoxy group, a triethylsilylbenzyloxy group, a triisopropylsilylmethoxy group, a triisopropylsilylethoxy group, a triisopropylsilylphenoxy group, a triisopropylsilylbenzyloxy group, a triphenylsilylmethoxy group, a triphenylsilylethoxy group, a triphenylsilylphenoxy group, a triphenylsilyl Examples of such a group include a tert-butyldimethylsilylbenzyloxy group, a tert-butyldimethylsilylmethoxy group, a tert-butyldimethylsilylethoxy group, a tert-butyldimethylsilylphenoxy group, a tert-butyldimethylsilylbenzyloxy group, a di-tert-butylisobutylsilylmethoxy group, a di-tert-butylisobutylsilylethoxy group, a di-tert-butylisobutylsilylphenoxy group, a di-tert-butylisobutylsilylbenzyloxy group, a tert-butyldiphenylsilylmethoxy group, a tert-butyldiphenylsilylethoxy group, a tert-butyldiphenylsilylphenoxy group, and a tert-butyldiphenylsilylbenzyloxy group.

[0027] The ester group having 1 to 11 carbon atoms in the above formula (1) of the present embodiment is not particularly limited, and examples thereof include a methyl ester group, an ethyl ester group, a propyl ester group, a butyl ester group, a pentyl ester group, a cyclopentyl ester group, a hexyl ester group, a cyclohexyl ester group, a heptyl ester group, an octyl ester group, a nonanyl ester group, a decyl ester group, a phenyl ester group, a benzyl ester group, a vinyl ester group, and an allyl ester group.

[0028] The acyl group having 1 to 11 carbon atoms in the above formula (1) of this embodiment is not particularly limited, but examples thereof include a formyl group, an acetyl group, a propionyl group, a butyryl group, a valeryl group, and a benzoyl group.

[0029] Examples of the unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms in the above formula (1) of this embodiment include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, an n-heptyl group, a 1-norbornyl group, a 2-norbornyl group, an n-octyl group, a 1-bicyclo[2.2.2]octyl group, a 2-bicyclo[2.2.2]octyl group, an n-nonanyl group, an n-decyl group, a 1-adamantyl group, and a 2-adamantyl group.

[0030] The cyclic carbonate of this embodiment preferably exhibits a single endothermic peak derived from melting at 100 to 200°C when heated under a nitrogen atmosphere in thermogravimetry / differential thermal analysis (TG / DTA). The cyclic carbonate of this embodiment tends to be able to maintain its shape better in a high-temperature environment because the single endothermic peak derived from melting is within the above range. From the same viewpoint, the endothermic peak temperature is preferably 110°C or higher and 200°C or lower, more preferably 110°C or higher and 190°C or lower. The endothermic peak temperature derived from melting can be specifically measured by the method described in the Examples.

[0031] In the cyclic carbonate resin of the present embodiment, in order to control the endothermic peak temperature due to melting within the above-mentioned preferred range, R 1 ~R 4 The cyclic carbonate may be produced by the production method described below.

[0032] The cyclic carbonate of this embodiment preferably has a weight loss rate of 5% by mass or less when heated to 150° C. under a nitrogen atmosphere in thermogravimetry / differential thermal analysis (TG / DTA). The cyclic carbonate of this embodiment has a weight loss rate within the above range, which tends to suppress volatilization and thermal decomposition in a high-temperature environment. From the same viewpoint, the weight loss rate of the cyclic carbonate of this embodiment up to 150° C. is more preferably 4.8% by mass or less, and even more preferably 4.5% by mass or less. Since the lower limit of the weight loss rate is preferably as low as possible, there is no lower limit, but it may be, for example, 0% by mass, 0.05% by mass, or 0.1% by mass. The weight loss rate when heated to 150° C. can be specifically measured by the method described in the Examples.

[0033] In the cyclic carbonate of the present embodiment, in order to control the weight loss rate when heated to 150° C. within the above-mentioned preferred range, R 1 ~R 4 The cyclic carbonate may be produced by the production method described below. 1 ~R 4 When is selected, the weight loss rate tends to be small.

[0034] The cyclic carbonate of this embodiment preferably has a weight loss rate of 30% by mass or less when heated to 200° C. under a nitrogen atmosphere in thermogravimetry / differential thermal analysis (TG / DTA). The cyclic carbonate of this embodiment has a weight loss rate within the above range, so that the cyclic carbonate tends to be able to maintain its shape even more in a high-temperature environment. From the same viewpoint, the weight loss rate of the cyclic carbonate of this embodiment up to 200° C. is more preferably 28% by mass or less, and even more preferably 25% by mass or less. Since the lower limit of the weight loss rate is preferably as low as possible, there is no lower limit, but it may be, for example, 0% by mass, 0.1% by mass, 0.5% by mass, or 1% by mass. The weight loss rate when heated to 200° C. can be specifically measured by the method described in the Examples.

[0035] In the cyclic carbonate of the present embodiment, in order to control the weight loss rate when heated to 200° C. within the above-mentioned preferred range, R 1 ~R 4 The cyclic carbonate may be produced by the production method described below. 1 ~R 4 When is selected, the weight loss rate tends to be small.

[0036] From the viewpoint of suppressing thermal weight loss in a high-temperature environment, the compound represented by the above formula (1) is preferably a compound represented by the following formula (2), and more preferably a compound represented by the following formula (4). [ka] [ka]

[0037] In formula (2), R 1 , R 2 , R 3 , R 4are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Preferred R in formula (2) 1 ~R 4 are the same as those in formula (1). In formula (2), examples of the phosphate group, the aryl group having 6 to 20 carbon atoms, the aralkyl group having 6 to 20 carbon atoms, the alkoxy group having 1 to 10 carbon atoms, the silyl group having 1 to 30 carbon atoms, the silylalkoxy group having 1 to 30 carbon atoms, the ester group having 1 to 11 carbon atoms, the acyl group having 1 to 11 carbon atoms, and the unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms are also the same as those in formula (1).

[0038] From the viewpoint of suppressing thermal weight loss in a high-temperature environment, the compound represented by the above formula (1) is preferably a compound represented by the following formula (3), and more preferably a compound represented by the following formula (5). [ka] [ka]

[0039] In formula (3), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 are each independently a hydrogen atom, a hydroxyl group, a phosphate group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a silyl group having 1 to 30 carbon atoms, a silylalkoxy group having 1 to 30 carbon atoms, an ester group having 1 to 11 carbon atoms, an acyl group having 1 to 11 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Preferred R in formula (3) 1 ~R 8 is R in formula (1). 1 ~R 4 In addition, in formula (3), examples of the phosphate group, the aryl group having 6 to 20 carbon atoms, the aralkyl group having 6 to 20 carbon atoms, the alkoxy group having 1 to 10 carbon atoms, the silyl group having 1 to 30 carbon atoms, the silylalkoxy group having 1 to 30 carbon atoms, the ester group having 1 to 11 carbon atoms, the acyl group having 1 to 11 carbon atoms, and the unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms are also the same as those in formula (1).

[0040] <Method for producing cyclic carbonates; hydrolysis of epoxides> The method for producing a cyclic carbonate according to the present embodiment includes a step of obtaining a cyclic carbonate from a diol compound obtained by hydrolyzing an epoxide (A1) represented by the following formula (6) under acidic or neutral conditions.

[0041] [ka]

[0042] In formula (6), R 1 , R 2 , R 3 , R 4 , n is as explained in relation to formula (1).

[0043] In this embodiment, the epoxide (A1) includes epoxides (B1) to (B4) represented by the following formulas (6-1) to (6-4). [ka] [ka] [ka] [ka]

[0044] In formulas (6-1) to (6-4), R 1 ~R 4 , n is as explained in relation to formula (1).

[0045] (acid catalyst) In this embodiment, an acid may be used as a catalyst for hydrolyzing the epoxide. The acid may include, but is not limited to, inorganic and organic acids such as hydrochloric acid, sulfuric acid, nitric acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, phosphoric acid, metaphosphoric acid, formic acid, acetic acid, propionic acid, butyric acid, lactic acid, citric acid, ascorbic acid, gluconic acid, oxalic acid, tartaric acid, Meldrum's acid, and benzoic acid.

[0046] <Method for producing cyclic carbonates; carbonyl source> The method for producing a cyclic carbonate of this embodiment includes a step of reacting a diol (C1) represented by the following formula (7) with a halogenated formate or a carbonate as a carbonyl source to obtain a cyclic carbonate.

[0047] [ka]

[0048] In formula (7), R 1 , R 2 , R 3 , R 4 , n is as explained in relation to formula (1).

[0049] In this embodiment, the diol (C1) includes epoxides (D1) and (D2) represented by the following formulas (7-1) and (7-2). [ka] [ka]

[0050] In formulas (7-1) and (7-2), R 1 ~R 4 , n is as explained in relation to formula (1).

[0051] (Halogenated formates) In the present embodiment, the halogenated formate ester is not particularly limited, but examples thereof include methyl chloroformate, ethyl chloroformate, methyl bromoformate, ethyl bromoformate, methyl iodoformate, and ethyl iodoformate.

[0052] (carbonate ester) In the present embodiment, the carbonate ester is not particularly limited, but examples thereof include dimethyl carbonate, diethyl carbonate, propyl carbonate, isopropyl carbonate, butyl carbonate, isobutyl carbonate, pentyl carbonate, isopentyl carbonate, cyclopentyl carbonate, hexyl carbonate, isohexyl carbonate, cyclohexyl carbonate, diphenyl carbonate, p-nitrophenyl carbonate, and dibenzyl carbonate.

[0053] (Carbonation catalyst) In the present embodiment, the step of reacting the diol (C1) with a halogenated formate ester or a carbonate ester may use a base catalyst. The base catalyst is not particularly limited, but examples thereof include organic bases such as cyclic amines such as cyclic monoamines and cyclic diamines (particularly, cyclic diamine compounds having an amidine skeleton), triamine compounds having a guanidine skeleton, and heterocyclic compounds containing a nitrogen atom. Examples of the organic base include, but are not limited to, triethylamine, diisopropylethylamine, 1,4-diazabicyclo-[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), diphenylguanidine (DPG), N,N-dimethyl-4-aminopyridine (DMAP), imidazole, pyrimidine, and purine.

[0054] (solvent) In the method for producing the cyclic carbonate of the present embodiment, a solvent may be used. The solvent is not particularly limited, but examples thereof include ether solvents such as diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,4-dioxane, cyclopentyl methyl ether, tert-butyl methyl ether, and propylene glycol monomethyl ether acetate, halogen solvents such as methylene chloride, chloroform, dichloromethane, dichloroethane, and trichloroethane, saturated hydrocarbon solvents such as hexane, heptane, octane, nonane, cyclohexane, and methylcyclohexane, aromatic hydrocarbon solvents such as toluene, xylene, o-xylene, m-xylene, p-xylene, and cresol, and ketone solvents such as acetone, 2-butanone, 2-pentanone, 3-pentanone, cyclopentanone, cyclohexanone, and methyl isobutyl ketone.

[0055] The cyclic carbonate of this embodiment has excellent heat resistance and can therefore be suitably used as an electrolyte or additive for lithium ion batteries, and as a raw material for highly heat-resistant polycarbonate resin. EXAMPLES

[0056] The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0057] In this specification, the physical properties of the cyclic carbonate were measured as follows.

[0058] (NMR measurement) Using a JEOL Ltd. NMR device (product name: ECZ400S) and a TFH probe, NMR measurements were performed as follows to determine the structure of cyclic carbonates. 1 H-NMR spectrum, 13 C-NMR spectra were obtained. Note that the base peak of the deuterated solvent was δH 7.26 ppm, δ C The total was 77.0 ppm. The number of measurements was 1 H-NMR, 13 C-NMR measurements were performed 32 times and 4000 times, respectively.

[0059] (Thermogravimetric measurement) About 10 mg of the cyclic carbonate obtained in the examples and comparative examples described below was used as a measurement sample, and a differential thermal / thermogravimetric simultaneous measurement device (manufactured by Shimadzu Corporation, product name "DTG-60A") was used to increase the temperature from 40°C to 100°C at 10°C / min under a nitrogen atmosphere, hold at 100°C for 5 minutes, and then increase the temperature from 100°C to 400°C at 10°C / min to perform thermogravimetry and differential thermal measurements of the cyclic carbonate. Note that for the ethylene carbonate of Comparative Example 2, the temperature increase started from 35°C. From the obtained results, the endothermic peak temperature (°C) in the differential thermal analysis and the weight loss rate (mass%) up to 200°C in the thermogravimetric analysis were calculated.

[0060] [Example 1] (Synthesis of 2,7-dihydroxynorbornane) Epoxynorbornene (9.98 g, 90.6 mmol) and 1 mol / L hydrochloric acid (200 mL) were weighed into a 500 mL three-neck flask and stirred at 100°C for 5 hours. After cooling, the mixture was extracted with chloroform and concentrated under reduced pressure using an evaporator. The resulting concentrate was subjected to column chromatography using 60 g of silica gel (developing solvent: ethyl acetate / heptane = 1:1 v / v; Rf = 0.25) to obtain 2,7-dihydroxynorbornane (3.3 g) as a white solid.

[0061] (Synthesis of norbornane-2,7-carbonate) 2,7-Dihydroxynorbornane (1.37g, 10.7mmol), diphenyl carbonate (2.63g, 12.3mmol), and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (31.2mg, 0.224mmol) were weighed and added to a 50mL three-neck flask. After replacing the inside with nitrogen, 2-methyltetrahydrofuran (15mL) was added to dissolve the contents. The flask was stirred at 80°C for 6 hours. After adding acetic acid to stop the reaction, the reaction liquid was concentrated under reduced pressure using an evaporator. The obtained concentrate was subjected to column chromatography using 60g of silica gel (developing solvent: ethyl acetate / heptane=1:5v / v; Rf=0.07) to obtain norbornane-2,7-carbonate (1.13g) as a white solid. 1 H-NMR spectrum, 13 The C-NMR spectrum was as follows. The NMR charts are shown in Figures 1 and 2. 1 H-NMR: δ H 1.16-1.26(2H), 1.46-1.56(1H), 1.70-1.81(2H), 2.01-2.07(1H), 2.37(1H), 2.62(1H), 4.44(1H), 4.51(1H). 13 C-NMR: δ C 18.4, 24.4, 35.8, 37.3, 40.5, 79.5, 85.6, 148.8. Thermogravimetric and differential thermal analyses were performed on the obtained cyclic carbonate, and as a result, an endothermic peak due to melting was observed at 158°C in differential thermal analysis in a nitrogen atmosphere. Furthermore, in thermogravimetric analysis in a nitrogen atmosphere, the weight loss rate at 150°C was 4.1% by mass, and the weight loss rate at 200°C was 24.3% by mass.

[0062] [Example 2] (Synthesis of epoxytetracyclododecene) Under an argon atmosphere, tetracyclododecene (25.0 g, 156 mmol), sodium hydrogen carbonate (14.2 g, 168 mmol), and chloroform (740 mL) were added to a 2 L four-neck flask, and the mixture was cooled in an ice bath while stirring with a mechanical stirrer using a stirring blade. m-Chloroperbenzoic acid (70 mass%, 43.84 g, 178 mmol) was added in three portions. After the addition was completed, the mixture was stirred overnight in the ice bath and warmed to room temperature. After stirring for 18 hours, the reaction solution was filtered under reduced pressure, and the filtration residue was rinsed with chloroform (200 mL x 4). A saturated aqueous solution of sodium thiosulfate (500 mL) was added to the filtrate, and the mixture was stirred for 10 minutes. After standing, the organic layer was collected, and a saturated aqueous solution of sodium hydrogen carbonate (500 mL) was added and stirred for 10 minutes. After standing, the organic layer was collected and washed with saturated saline (1 L). The collected organic layer was dried over sodium sulfate. The organic layer after drying was concentrated using an evaporator. The obtained concentrate was subjected to column chromatography (eluent: ethyl acetate / heptane = 1:19 v / v) using 280 g of amino silica gel to obtain epoxytetracyclododecene (26.2 g) as a colorless, transparent solid.

[0063] (Hydrolysis and Carbonation of Epoxytetracyclododecene) Epoxytetracyclododecene (3.03 g, 17.2 mmol) was weighed out and placed in a 100 mL three-neck flask, and the inside of the flask was replaced with nitrogen. Under a nitrogen stream, 1 mol / L hydrochloric acid (15 mL) and ion-exchanged water (15 mL) were weighed and added, and the mixture was stirred at 100°C for 2 hours. After cooling, the mixture was extracted with chloroform (30 mL x 3). The collected organic layer was washed with a saturated aqueous solution of sodium bicarbonate (50 mL) and saturated saline (50 mL). The collected organic layer was dried over sodium sulfate. The dried organic layer was concentrated under reduced pressure using an evaporator. The obtained concentrate was subjected to column chromatography using 60 g of silica gel (developing solvent: ethyl acetate / heptane = 1:1 v / v; Rf = 0.40) to obtain tetracyclododecane-2,10-diol (2.07 g) as a transparent oil. Next, tetracyclododecanediol (1.02 g, 5.25 mmol), diphenyl carbonate (1.33 g, 6.21 mmol), and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (18.0 mg, 0.129 mmol) were weighed and added to a 25 mL three-neck flask. After replacing the inside with nitrogen, 2-methyltetrahydrofuran (9 mL) was added to dissolve the contents. The flask was stirred at 70°C for 2 hours. After adding acetic acid to stop the reaction, the reaction liquid was concentrated under reduced pressure using an evaporator. The obtained concentrate was subjected to column chromatography using 50 g of silica gel (developing solvent: ethyl acetate / heptane = 1:5 v / v; Rf = 0.13) to obtain tetracyclododecane-2,10-carbonate (0.91 g) as a white solid. 1 H-NMR spectrum, 13 The C-NMR spectrum was as follows: The NMR charts are shown in Figures 3 and 4. 1 H-NMR: δ H 1.07-1.10(3H),1.37-1.55(5H),1.75-1.81(1H),2.15(1H),2.25(1H),2.28(1H),2.63(1H),4.37(1H),5.17(1H). 13 C-NMR: δ C 28.9, 30.9, 36.5, 38.3, 39.1, 39.4, 42.2, 44.8, 45.0, 51.0, 78.3, 85.0, 149.3. Thermogravimetric and differential thermal analyses were performed on the obtained cyclic carbonate, and as a result, an endothermic peak due to melting was observed at 122°C in differential thermal analysis in a nitrogen atmosphere. Furthermore, in thermogravimetric analysis in a nitrogen atmosphere, the weight loss rate at 150°C was 0.5% by mass, and the weight loss rate at 200°C was 2.9% by mass.

[0064] [Comparative Example 1] (Synthesis of trans-cyclohexene carbonate) Under an argon stream, trans-1,2-cyclohexanediol (200.0 g, 1.722 mmol) and dehydrated 1,4-dioxane (2.0 L) were added to a 5 L four-neck flask. Next, while stirring using a mechanical stirrer and cooling the reaction vessel in an ice bath, ethyl chloroformate (280.2 g, 2.582 mmol) was slowly dropped into the reaction liquid. Furthermore, while maintaining stirring and cooling, a solution obtained by diluting triethylamine (348.4 g, 3.443 mmol) with dehydrated toluene (2.5 L) was slowly dropped into the reaction liquid. After dropping, the mixture was stirred for 1.5 hours while maintaining cooling, and then the internal temperature of the reaction vessel was raised to room temperature and stirred for another 12 hours. The by-product white solid was removed by filtration under reduced pressure, and the filtrate was concentrated under reduced pressure. Ethyl acetate (2.0 L) was added to the residue to dissolve it, and the mixture was washed with 1% by mass aqueous hydrochloric acid solution (2.0 L). The organic layer was collected and washed three times with ion-exchanged water (2.0 L). Magnesium sulfate was added to the organic layer for dehydration, and then the organic layer was filtered under reduced pressure. The filtrate was concentrated under reduced pressure to obtain a white solid, which was then purified by silica gel column chromatography to obtain the desired trans-cyclohexene carbonate (110 g). Thermogravimetric and differential thermal analyses were performed on the obtained cyclic carbonate, and as a result, an endothermic peak due to melting was observed at 60°C in differential thermal analysis in a nitrogen atmosphere. Furthermore, in thermogravimetric analysis in a nitrogen atmosphere, the weight loss rate at 150°C was 8.4% by mass, and the weight loss rate at 200°C was 57.6% by mass.

[0065] [Comparative Example 2] Thermogravimetric and differential thermal analysis of commercially available ethylene carbonate (Tokyo Chemical Industry Co., Ltd., purity >99.0%) showed that an endothermic peak due to melting was observed at 39°C in differential thermal analysis in a nitrogen atmosphere. Furthermore, the weight loss rate at 150°C in thermogravimetric analysis in a nitrogen atmosphere was 20.5% by mass, and the weight loss rate at 200°C was 99.2% by mass.

[0066] Table 1 shows the physical properties of the cyclic carbonates obtained in the examples and comparative examples.

[0067] [Table 1]

[0068] As can be seen from Table 1, the cyclic carbonates of Examples 1 and 2, when heated under a nitrogen atmosphere by thermogravimetry and differential thermal analysis, had significantly higher endothermic peak temperatures of the differential heat due to melting, and significantly smaller weight loss rates at 150°C and 200°C, compared to the cyclic carbonate of the comparative example, indicating that they had excellent heat resistance. [Industrial Applicability]

[0069] The cyclic carbonate of the present invention has industrial applicability in fields such as various battery materials, such as electrolytes and additives for lithium ion secondary batteries, and various resin materials, such as polycarbonate resins, which require high heat resistance.

Claims

1. The following formula (1): 【Chemistry 1】 (In formula (1), R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; R 1 ~R 4 may form a cyclic structure together with the carbon atom to which they are bonded, and in the cyclic structure, R 1 ~R 4 are bonded to each other via an alkylene group, n is an integer of 0 or 1. A cyclic carbonate represented by the formula:

2. The following formula (2): 【Chemistry 2】 (In formula (2), R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. A cyclic carbonate represented by the formula:

3. The following formula (3): 【Chemistry 3】 (In formula (3), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are each independently a hydrogen atom, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. A cyclic carbonate represented by the formula:

4. The following formula (4): 【Chemistry 4】 The cyclic carbonate according to claim 1 or 2, wherein

5. The following formula (5): 【Chemistry 5】 The cyclic carbonate according to claim 1 or 3, wherein

6. A method for producing a cyclic carbonate according to any one of claims 1 to 5, The following formula (6): 【Chemistry 6】 The epoxide represented by the formula (7): 【Chemistry 7】 and a step of reacting the diol compound with a halogenated formate ester or a carbonate ester to obtain a cyclic carbonate; A manufacturing method comprising: (In formulas (6) and (7), R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, or an unsubstituted linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; R 1 ~R 4 may form a cyclic structure together with the carbon atom to which they are bonded, and in the cyclic structure, R 1 ~R 4 are bonded to each other via an alkylene group, n is an integer of 0 or 1.

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