Divinylbenzylfluorene compound and method for producing the same

Abstract

Provided is a divinylbenzylfluorene compound that can achieve both solubility in methyl ethyl ketone and a high melting point. The divinylbenzylfluorene compound according to the present invention is a compound represented by the following general formula (1), in which R 1 , R 2 and R 3 each independently represents a hydrocarbon group having 1 to 5 carbon atoms, a, b, and c each independently represent an integer of 0 to 4, and the ratio of p,p-isomers in which the two vinylbenzyl groups in formula (1) are both para isomers is 20 to 50%. [Formula 1] JPEG0007795668000016.jpg48161

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to a divinylbenzylfluorene compound, a curable resin composition containing the compound, a cured product thereof, and a method for producing the divinylbenzylfluorene compound. [Background technology]

[0002] Conventionally, divinylbenzylfluorene compounds have been known as compounds used in resin materials for printed wiring boards, etc. For example, Patent Document 1 discloses a compound obtained by reacting a fluorene compound with a vinylbenzyl halide compound, where α is the number of moles of a fluorene compound, β1 is the number of moles of a para vinylbenzyl halide compound, β2 is the number of moles of a meta vinylbenzyl halide compound, and (β1+β2) / α is 1.8 to 2.1.

[0003] Patent Document 2 discloses a divinylbenzylfluorene compound characterized by having a melting point of 130°C or less or no melting point, and discloses that the ratio of p-isomer / (m-isomer+p-isomer) of the vinylbenzyl group in the compound is 0.6 to 1.0. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2024 / 111414 [Patent Document 2] Japanese Patent Publication No. 2022-167558 Summary of the Invention [Problem to be solved by the invention]

[0005] Since the divinylbenzylfluorene compound has two polymerizable unsaturated bonds, it can be used as a component of a curable resin composition that is cured by heat, light, electron beams, etc. From the viewpoint of formulation design of such a curable resin composition, it is desirable for the divinylbenzylfluorene compound to have improved solubility in organic solvents such as methyl ethyl ketone. Furthermore, from the viewpoint of processing conditions when producing a resin product using the curable resin composition, it is sometimes desirable for the divinylbenzylfluorene compound to have a high melting point.

[0006] The above-mentioned Patent Document 1 discloses the molar numbers of para and meta vinylbenzyl halide compounds used in the production of divinylbenzyl fluorene compounds. Furthermore, the above-mentioned Patent Document 2 discloses the ratio of para vinylbenzyl groups to the total amount of para and meta vinylbenzyl groups in divinylbenzyl fluorene compounds. However, these patent documents do not disclose setting the ratio of p,p-isomers, in which both vinylbenzyl groups in one molecule are para, within a specific range, nor does it disclose that this allows for both a high melting point and solubility to be achieved.

[0007] An object of an embodiment of the present invention is to provide a divinylbenzylfluorene compound that can achieve both solubility in methyl ethyl ketone and a high melting point. [Means for solving the problem]

[0008] The present invention includes the embodiments shown below. [1] A divinylbenzylfluorene compound represented by the following general formula (1): [ka] R in general formula (1) 1 , R 2 and R 3 each independently represents a hydrocarbon group having 1 to 5 carbon atoms, a, b, and c each independently represent an integer of 0 to 4, A divinylbenzylfluorene compound represented by the general formula (1), in which the ratio of p,p-isomers, in which two vinylbenzyl groups are both para-isomers, is 20 to 50%.

[0009] [2] The divinylbenzylfluorene compound according to [1], which has a solubility in methyl ethyl ketone at 22°C of 20% by mass or more.

[0010] [3] The divinylbenzylfluorene compound according to [1] or [2], which has a melting point of more than 130°C and not more than 200°C.

[0011] [4] A curable resin composition containing the divinylbenzylfluorene compound according to any one of [1] to [3].

[0012] [5] A cured product obtained by curing the divinylbenzylfluorene compound according to any one of [1] to [3] or the curable resin composition according to [4].

[0013] [6] A method for producing a vinylbenzyl halide compound represented by the following general formula (3) in a molar ratio of meta-isomer to para-isomer of 30 / 70 to 60 / 40, in an aprotic polar solvent having a boiling point of less than 100°C in the presence of an alkali, comprising reacting a fluorene compound represented by the following general formula (2) with a vinylbenzyl halide compound represented by the following general formula (3) in a molar ratio of meta-isomer to para-isomer of 30 / 70 to 60 / 40 in an aprotic polar solvent having a boiling point of less than 100°C in the presence of an alkali; and precipitating the obtained product in a mixed solvent of an alcohol having 1 to 4 carbon atoms and water, [ka] R in general formula (2) 1 and R 2 each independently represents a hydrocarbon group having 1 to 5 carbon atoms, a and b each independently represent an integer of 0 to 4, [ka] R in general formula (3) 3 represents a hydrocarbon group having 1 to 5 carbon atoms, c represents an integer of 0 to 4, and X represents a halogen atom. A method for producing a divinylbenzylfluorene compound.

[0014] [7] The method for producing a divinylbenzylfluorene compound according to [6], further comprising washing the product obtained by the reaction with water, and carrying out the precipitation after the washing with water.

[0015] [8] The method for producing a divinylbenzylfluorene compound according to [6] or [7], wherein the aprotic polar solvent is methyl ethyl ketone.

[0016] [9] The method for producing a divinylbenzylfluorene compound according to any one of [6] to [8], wherein the amount of water in the mixed solvent is 20 to 40 mass %. [Effects of the Invention]

[0017] According to this embodiment, since the ratio of p,p-isomer is 20 to 50%, it is possible to provide a divinylbenzylfluorene compound that has a high melting point and improved solubility in methyl ethyl ketone.

[0018] The production method according to this embodiment can improve the yield of the divinylbenzylfluorene compound. DETAILED DESCRIPTION OF THE INVENTION

[0019] The divinylbenzylfluorene compound according to this embodiment is represented by the following general formula (1). [ka]

[0020] R in formula (1) 1 , R 2 and R 3 represents a substituent substituting a hydrogen atom on the aromatic ring, and each independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, more preferably a hydrocarbon group having 1 or 2 carbon atoms. The hydrocarbon group is preferably an alkyl group. 1 , R 2 and R3 When there are a plurality of each of the groups, they may be the same or different.

[0021] In formula (1), a, b, and c each independently represent an integer of 0 to 4, preferably 0 or 1, and more preferably 0. That is, the substituent R 1 ~R 3 Preferably, it is an unsubstituted divinylbenzylfluorene having no

[0022] In the divinylbenzylfluorene compound according to this embodiment, the ratio of the p,p-isomer, in which both vinylbenzyl groups in formula (1) are para-isomers, is 20 to 50%. The higher the ratio of the p,p-isomer, the more improved the solubility of the divinylbenzylfluorene compound in organic solvents such as methyl ethyl ketone (MEK). On the other hand, if the ratio of the p,p-isomer is too high, the melting point decreases. By setting the ratio of the p,p-isomer to 20 to 50%, it is possible to improve the solubility in MEK while maintaining a high melting point. The ratio of the p,p-isomer is preferably 23 to 45%, more preferably 25 to 40%.

[0023] where the ratio of p,p-isomers is 13 It is the ratio of the peak area of ​​the peak derived from benzyl carbon in C-NMR, and corresponds to the amount (molar ratio) of p,p-isomer when the amount of all isomers of the divinylbenzylfluorene compound is taken as 100% (the same applies to the total ratio of p,m-isomer and m,m-isomer described later). The detailed measurement method is as described in the Examples section.

[0024] Regarding the vinylbenzyl group, the para isomer (paravinylbenzyl) refers to a structure in which the vinyl group is bonded to the benzylic carbon at the para position. The meta isomer (metavinylbenzyl) refers to a structure in which the vinyl group is bonded to the benzylic carbon at the meta position. The same applies to the para and meta isomers of vinylbenzyl halide compounds.

[0025] The p,p-isomer is represented by the following general formula (1-1). [ka] R in formula (1-1) 1 , R 2 , R 3 , a, b, and c are R in formula (1), respectively. 1 , R 2 , R 3 , a, b and c.

[0026] In one embodiment, the divinylbenzylfluorene compound contains the p,p-isomer as well as the p,m-isomer and / or the m,m-isomer. The ratio of the p,m-isomer and the m,m-isomer in total is preferably 50 to 80%, more preferably 55 to 77%, and even more preferably 60 to 75%. The total ratio of the p,p-isomer, the p,m-isomer, and the m,m-isomer is not particularly limited and may be, for example, 80% or more, 85% or more, 90% or more, 95% or more, or even 100%.

[0027] Here, the p,m-isomer is an isomer in which one of the two vinylbenzyl groups in the above formula (1) is a para isomer and the other is a meta isomer, and is therefore represented by the following general formula (1-2). [ka] R in formula (1-2) 1 , R 2 , R 3 , a, b, and c are R in formula (1), respectively. 1 , R 2 , R 3 , a, b and c.

[0028] The m,m-isomer is an isomer in which both of the two vinylbenzyl groups in the above formula (1) are meta-isomers, and is therefore represented by the following general formula (1-3). [ka] R in formula (1-3) 1 , R2 , R 3 , a, b, and c are R in formula (1), respectively. 1 , R 2 , R 3 , a, b and c.

[0029] As described above, the divinylbenzylfluorene compound according to the embodiment has a p,p-isomer ratio of 20 to 50%, and therefore has a high melting point and excellent solubility in MEK. In one embodiment, the solubility of the divinylbenzylfluorene compound in MEK is preferably 20% by mass or more. Here, the solubility is the concentration of a saturated solution at 22°C, i.e., the mass % of the divinylbenzylfluorene compound in 100% by mass of a saturated solution, and detailed measurement methods are as described in the Examples section. The solubility in MEK is more preferably 21% by mass or more. Since a higher solubility is preferable, the upper limit is not particularly limited, but may be 30% by mass (e.g., 20 to 30% by mass) or 28% by mass (e.g., 21 to 28% by mass).

[0030] In one embodiment, the melting point of the divinylbenzylfluorene compound is preferably higher than 130°C and lower than 200°C. Here, the melting point is the melting point under 1 atmosphere, and detailed measurement methods are as described in the Examples section. The melting point of the divinylbenzylfluorene compound is more preferably higher than 130°C and lower than 150°C, and more preferably 131°C or higher and 140°C or lower.

[0031] In one embodiment, the solubility of the divinylbenzylfluorene compound in toluene at 22° C. is preferably greater than 20% by mass, more preferably 20.5% by mass or greater. Since a higher solubility is preferable, the upper limit is not particularly limited, and may be 30% by mass (e.g., 20 to 30% by mass) or 25% by mass (e.g., 20.5 to 25% by mass).

[0032] In one embodiment, the exothermic peak temperature of the divinylbenzylfluorene compound is preferably 135° C. to 200° C., more preferably 140° C. to 160° C., and even more preferably 140° C. to 150° C. Here, the exothermic peak temperature is the temperature at the exothermic peak measured by differential scanning calorimetry (DSC), and detailed measurement methods are as described in the Examples section.

[0033] The method for producing the divinylbenzyl fluorene compound according to the present embodiment is not particularly limited. In one embodiment, a fluorene compound represented by the following general formula (2) is reacted with a vinylbenzyl halide compound represented by the following general formula (3) in a specific solvent in the presence of an alkali, and the resulting product is precipitated in a mixed solvent of alcohol and water, thereby obtaining the divinylbenzyl fluorene compound.

[0034] Here, the vinylbenzyl halide compound used has a meta / para molar ratio of 30 / 70 to 60 / 40. An aprotic polar solvent with a boiling point of less than 100°C is used as the solvent during the reaction (reaction solvent). A mixed solvent of an alcohol having 1 to 4 carbon atoms and water is used as the solvent for precipitation (precipitation solvent). By employing such a production method, a divinylbenzylfluorene compound having a p,p-isomer ratio of 20 to 50% can be obtained, and the yield can be improved.

[0035] [ka] R in equation (2) 1 , R 2 , a and b are R in formula (1), 1 , R 2 , a and b are the same as above. As the fluorene compound, one type may be used alone, or two or more types having different substituents may be used in combination.

[0036] [ka] R in equation (3)3 and c are R in formula (1), respectively. 3 and c are the same as those in (a) and (b). X represents a halogen atom, preferably a chlorine atom or a bromine atom, and more preferably a chlorine atom. The vinylbenzyl halide compound may be used alone or in combination of two or more types having different substituents.

[0037] In the vinylbenzyl halide compound represented by formula (3), the molar ratio of meta-isomer to para-isomer is 30 / 70 to 60 / 40, as described above, and preferably 35 / 65 to 55 / 45. When the molar ratio is 60 / 40 or less, the ratio of p,p-isomer can be increased. When the molar ratio is 30 / 70 or more, the ratio of p,p-isomer can be reduced.

[0038] In the vinylbenzyl halide compound, the total ratio of meta and para isomers is, for example, preferably 80 mol % or more, more preferably 90 mol % or more, more preferably 95 mol % or more, and may be 100 mol %.

[0039] As described above, an aprotic polar solvent with a boiling point of less than 100°C is used as the reaction solvent. This allows precipitation in a mixed solvent of alcohol and water after the reaction. It is more preferable to use an aprotic polar solvent with low solubility in water as the reaction solvent. Specifically, the solubility in water at 22°C is preferably 30% by mass or less, more preferably 5 to 30% by mass, more preferably 10 to 28% by mass, and even more preferably 15 to 25% by mass. Examples of such aprotic polar solvents include methyl ethyl ketone (MEK) and 2-methyltetrahydrofuran, with MEK being particularly preferred.

[0040] The alkali used in the reaction may be a hydroxide, alkoxide, or hydride of an alkali metal or alkaline earth metal, such as sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, sodium hydride, or potassium hydride. These may be used alone or in combination of two or more. The amount of alkali used is not particularly limited, and may be, for example, about 1.1 to 3.0 equivalents per equivalent of hydrogen at the 9-position of the fluorene compound. In one embodiment, the alkali may be dissolved in water and added to the reaction system containing the reaction solvent. When a reaction solvent with low solubility in water is used, the aqueous alkali solution and the reaction solvent may partially dissolve but are essentially immiscible, and the reaction proceeds in a finely dispersed state upon stirring.

[0041] A phase transfer catalyst may be used during the reaction. The phase transfer catalyst may be an onium salt, such as quaternary ammonium compounds such as tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltrimethylammonium chloride, and tricaprylmethylammonium chloride; or quaternary phosphonium compounds such as tetrabutylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium chloride, and tetraphenylphosphonium bromide. These may be used alone or in combination of two or more. The amount of the phase transfer catalyst used is not particularly limited, and may be, for example, about 0.01 to 0.2 equivalents relative to 1 equivalent of hydrogen at the 9-position of the fluorene compound.

[0042] The reaction temperature and reaction time are not particularly limited, and may be, for example, 30 to 100° C. and 0.5 to 20 hours.

[0043] After the reaction is complete, the resulting product is preferably washed with water, and the above-mentioned precipitation is carried out after the water washing, which can increase the purity of the divinylbenzylfluorene compound. Specifically, an acid is added to the liquid after the reaction, which contains an aprotic polar solvent solution in which the product has been dissolved and an alkaline aqueous solution, to neutralize the liquid, and the aqueous layer is separated and removed to remove the salt generated by the neutralization. Water is added to the organic layer (the aprotic polar solvent solution in which the product has been dissolved) after the water layer has been removed, and the mixture is stirred, and the aqueous layer is separated and removed, thereby washing the product with water. The water washing may be repeated multiple times. Next, the organic layer containing the product after the water layer has been removed is added to a mixed solvent of alcohol and water as a precipitation solvent, and precipitated in the mixed solvent. This yields the divinylbenzylfluorene compound according to the embodiment.

[0044] As the precipitation solvent, a mixed solvent of an alcohol having 1 to 4 carbon atoms (hereinafter also referred to as a lower alcohol) and water is used as described above, which can improve the yield. Examples of the lower alcohol include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol, and any one of these may be used alone or in combination of two or more. Methanol and / or ethanol are preferred, and methanol is more preferred.

[0045] Regarding the ratio of lower alcohol to water in the mixed solvent, it is preferable that the amount of water in the mixed solvent is 20 to 40% by mass, i.e., 20 to 40% by mass of water and 60 to 80% by mass of lower alcohol. By setting the water ratio in this manner, it becomes easier to adjust the ratio of p,p-isomers to within the range of 20 to 50%. Furthermore, a small water ratio can increase the drying efficiency of the product after precipitation. More preferably, the mixed solvent contains 25 to 35% by mass of water and 65 to 75% by mass of lower alcohol.

[0046] The divinylbenzylfluorene compound according to the present embodiment can be cured by itself by heating or the like, but may also be blended with various components such as a curing agent to form a curable resin composition. The divinylbenzylfluorene compound or the curable resin composition can be cured by heat, light, electron beam, or the like to obtain the cured product according to the present embodiment.

[0047] The curable resin composition according to the present embodiment contains the divinylbenzylfluorene compound, and may contain various additives, such as a curing agent, a copolymerizable monomer, an oligomer and / or a polymer, an inorganic filler, a photopolymerization initiator, a polymerization inhibitor, a flame retardant, and a colorant, together with the compound.

[0048] Examples of the curing agent include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, t-butylcumyl peroxide, methyl ethyl ketone peroxide, and dicumyl peroxide.

[0049] Examples of monomers, oligomers, and / or polymers copolymerizable with the divinylbenzylfluorene compound include oligomers or polymers having a polymerizable unsaturated group, such as vinyl ester resins, unsaturated polyester resins, and diallyl phthalate resins, and monofunctional or polyfunctional (meth)acrylic acid derivatives, such as styrene, vinyltoluene, and divinylbenzene.

[0050] The uses of the divinylbenzylfluorene compound and curable resin composition according to this embodiment are not particularly limited, and examples thereof include various resin materials such as printed wiring boards, semiconductor encapsulants, and optical components. [Example]

[0051] The present invention will be explained in more detail below based on examples and comparative examples, but the present invention is not limited thereto.

[0052] <Measurement and evaluation methods> [p,p-isomer ratio] Approximately 30 mg of each product in the Examples and Comparative Examples was dissolved in approximately 1 g of deuterated chloroform (containing 0.03% by mass of TMS (tetramethylsilane)) to prepare a sample. The sample was transferred to an NMR measurement tube with a diameter of 5 mm, and analyzed by the inversed decoupling method using a nuclear magnetic resonance spectrometer (manufactured by JEOL Ltd.). 13 C-NMR was measured under the following conditions: room temperature, pulse width 45°, delay time 50 seconds, and accumulation count 512.

[0053] 13 As a result of C-NMR measurement, peaks derived from four types of benzylic carbons, each having a peak top at 45.0 ppm, 45.2 ppm, 45.3 ppm, and 45.5 ppm, were detected in Examples 1 and 2 and Comparative Examples 1 and 2. On the other hand, in Comparative Example 3, which was synthesized using vinylbenzyl chloride with a meta / para molar ratio of 5 / 95, no peak at 45.3 ppm was detected, and a significantly large peak area was detected at 45.2 ppm.

[0054] In the following examples and comparative examples, fluorene and vinylbenzyl chloride are reacted, and a mixture of meta and para vinylbenzyl chloride is used. Therefore, the divinylbenzylfluorene compound (9,9-bis(vinylbenzyl)fluorene) can be synthesized as a p,p-isomer represented by the following formula (1-1A), a p,m-isomer represented by the following formula (1-2A), and an m,m-isomer represented by the following formula (1-3A). [ka]

[0055] Therefore, the four types of benzylic carbons are the benzylic carbon of the p,p-isomer, the benzylic carbon of the meta-isomer of the p,m-isomer, the benzylic carbon of the para-isomer of the p,m-isomer, and the benzylic carbon of the m,m-isomer. As described above, in Comparative Example 3, the peak at 45.3 ppm was not detected, and the peak area at 45.2 ppm was significantly larger. This indicates that the peak at 45.2 ppm is assigned to the benzylic carbon of the p,p-isomer, and the peak at 45.3 ppm is assigned to the benzylic carbon of the m,m-isomer. Therefore, the ratio of the peak area at 45.2 ppm to the total area of ​​the four peaks around 45 ppm was calculated as the p,p-isomer ratio.

[0056] [Melting point / exothermic peak temperature] For each product of the Examples and Comparative Examples, the melting point and exothermic peak temperature were measured by heating from room temperature to 350°C at a rate of 10°C / min under a nitrogen stream using a differential scanning calorimeter (manufactured by Rigaku Corporation).

[0057] [Solubility] 5 g of each product from the Examples and Comparative Examples was placed in a screw bottle, 11.7 g of toluene or methyl ethyl ketone (MEK) was added, and the mixture was shaken well and then left to stand overnight in a constant temperature and humidity chamber at 22°C. The supernatant was filtered through a syringe filter (pore size 0.45 μm) to obtain a saturated solution. The solid content of approximately 1 g of the saturated solution was measured using an infrared moisture meter (Kett Electric Laboratory) at 120°C for 30 minutes, and the concentration of the saturated solution was calculated from the solid content, which was used as the solubility of each product.

[0058] Example 1 In a 3 L reactor equipped with a condenser and a stirrer, 149.6 g of fluorene, 274.6 g of vinylbenzyl chloride (meta / para (molar ratio) = 50 / 50, trade name: CMS-P, manufactured by AGC Seimi Chemical Co., Ltd.), 13.2 g of tetrabutylammonium bromide, and 150.0 g of MEK were charged and dissolved at 40 ° C. Next, 300.0 g of 48 mass % aqueous sodium hydroxide solution was added, and the reaction solution was heated and reacted at 50 to 60 ° C. for 6 hours, after which 1050.9 g of MEK was added for dilution. 330.0 g of water and 196.8 g of 35 mass % hydrochloric acid were added to this, and the mixture was stirred at 45 to 55 ° C. for 15 minutes, and then allowed to stand, after which the aqueous layer was separated and removed. Further, 311.9 g of water was added, and the mixture was stirred at 45 to 55°C. After the operation of leaving the mixture to stand and separating and removing the aqueous layer was repeated twice, the resulting organic layer was added dropwise to a mixed solvent of 1949.5 g of water and 5848.4 g of methanol (MeOH), and the precipitated solid was collected and dried in vacuo at 40°C overnight, yielding 307.1 g of a product (yield 85.6% by mass).

[0059] Example 2 A 1-L reactor equipped with a condenser and a stirrer was charged with 74.8 g of fluorene, 103.0 g of vinylbenzyl chloride (meta / para (molar ratio) = 50 / 50, trade name: CMS-P, manufactured by AGC Seimi Chemical Co., Ltd.), 34.3 g of vinylbenzyl chloride (meta / para (molar ratio) = 5 / 95, trade name: CMS-14, manufactured by AGC Seimi Chemical Co., Ltd.), 6.6 g of tetrabutylammonium bromide, and 75.0 g of MEK, and dissolved at 40 °C. Next, 150.0 g of 48% by weight aqueous sodium hydroxide solution was added, and the reaction solution was heated to 50 to 60 °C and continued for 6 hours. After that, 525 g of MEK was added for dilution. 165.0 g of water and 95.6 g of 35% by weight hydrochloric acid were added to the mixture, and the mixture was stirred at 45 to 55 °C for 15 minutes, then allowed to stand and the aqueous layer was separated and removed. Further, 165.0 g of water was added, and the mixture was stirred at 45 to 55°C. After the operation of leaving the mixture to stand and separating and removing the aqueous layer was repeated twice, the resulting organic layer was added dropwise to a mixed solvent of 904.0 g of water and 2711.0 g of methanol, and the precipitated solid was collected and dried in vacuo at 40°C overnight to obtain 147.8 g of a product (yield 82.3% by mass).

[0060] (Comparative Example 1) In a 1 L reactor equipped with a condenser and a stirrer, 74.8 g of fluorene, 137.3 g of vinylbenzyl chloride (meta / para (molar ratio) = 50 / 50, trade name: CMS-P, manufactured by AGC Seimi Chemical Co., Ltd.), 6.6 g of tetrabutylammonium bromide, and 75.0 g of MEK were charged and dissolved at 40 °C. Next, 150.0 g of 48 mass% aqueous sodium hydroxide solution was added, and the reaction solution was heated and reacted at 50 to 60 °C for 7 hours, after which 525 g of MEK was added for dilution. 165.0 g of water and 95.6 g of 35 mass% hydrochloric acid were added to this, and the mixture was stirred at 45 to 55 °C for 15 minutes, and then allowed to stand, after which the aqueous layer was separated and removed. Further, 151.5 g of water was added, and the mixture was stirred at 45 to 55°C. After the procedure of leaving the mixture to stand and separating and removing the aqueous layer was repeated twice, the resulting organic layer was added dropwise to 3400 g of methanol, and the precipitated solid was collected and dried in vacuum at 40°C overnight to obtain 90.7 g of a product (yield 50.5% by mass).

[0061] (Comparative Example 2) In a 1 L reactor equipped with a condenser and a stirrer, 74.8 g of fluorene, 137.3 g of vinylbenzyl chloride (meta / para (molar ratio) = 50 / 50, trade name: CMS-P, manufactured by AGC Seimi Chemical Co., Ltd.), 6.6 g of tetrabutylammonium bromide, and 75.0 g of toluene were added and dissolved at 40 ° C. Next, 150.0 g of 48 mass% aqueous sodium hydroxide solution was added, and the reaction solution was heated to 50-60 ° C. and the reaction was continued for 11 hours, after which 343.4 g of toluene was added for dilution. To this, 165.0 g of water, 18.8 g of isopropanol, and 95.6 g of 35 mass% hydrochloric acid were added, and the mixture was stirred at 45-55 ° C. for 15 minutes, and then allowed to stand, followed by the separation and removal of the aqueous layer. Further, 30.0 g of water and 7.5 g of isopropanol were added, and the mixture was stirred at 45 to 55°C, and the mixture was left to stand and the aqueous layer was separated and removed. This procedure was repeated four times, and then 181.6 g of toluene was added for dilution. The resulting organic layer was added dropwise to 3738 g of methanol, and the precipitated solid was collected and dried in vacuo at 40°C overnight to obtain 72.2 g of product (yield: 40.3% by mass).

[0062] (Comparative Example 3) A 500 mL reactor equipped with a condenser and a stirrer was charged with 29.9 g of fluorene, 54.9 g of vinylbenzyl chloride (meta / para (molar ratio) = 5 / 95, product name: CMS-14, manufactured by AGC Seimi Chemical Co., Ltd.), 2.6 g of tetrabutylammonium bromide, and 30.0 g of MEK, and dissolved at 40°C. Next, 60.0 g of a 48% by mass aqueous sodium hydroxide solution was added, and the reaction solution was heated to 50-60°C and continued for 6 hours. After that, 210.2 g of MEK was added for dilution. 66.0 g of water and 39.4 g of 35% by mass hydrochloric acid were added to the mixture, and the mixture was stirred at 45-55°C for 15 minutes, and then allowed to stand, during which the aqueous layer was separated and removed. Further, 62.4 g of water was added, and the mixture was stirred at 45 to 55°C. After allowing to stand and separating and removing the aqueous layer, this operation was repeated twice. The resulting organic layer was then added dropwise to a mixed solvent of 389.9 g of water and 1,169.7 g of methanol, and the deposited sticky solid was collected and dried in vacuo at 40°C overnight to obtain 51.5 g of product (yield 71.8% by mass).

[0063] Comparative Example 4 A 500 mL reactor equipped with a condenser and stirrer was charged with 29.9 g of fluorene, 54.9 g of vinylbenzyl chloride (meta / para (molar ratio) = 50 / 50, product name: CMS-P, manufactured by AGC Seimi Chemical Co., Ltd.), and 30.0 g of dimethyl sulfoxide (DMSO) and dissolved at 45°C. Next, 60.0 g of 48% by mass aqueous sodium hydroxide solution was added, and the reaction solution was heated to 50-60°C and continued for 6 hours. After that, 210.2 g of DMSO was added for dilution. 66.0 g of water and 39.4 g of 35% by mass hydrochloric acid were added to this mixture, and the mixture was stirred at 45-55°C for 15 minutes. Upon allowing to stand, a product precipitated. Furthermore, the organic and aqueous layers did not separate, making it impossible to carry out subsequent operations.

[0064] The products of Examples 1 and 2 and Comparative Examples 1 to 3 were measured and evaluated for p,p-isomer ratio, melting point, exothermic peak temperature, solubility in toluene, and solubility in MEK. The results are shown in Table 1. In Table 1, "m / p of CMS" represents the molar ratio of meta-isomer to para-isomer of vinylbenzyl chloride used in the reaction.

[0065] [Table 1]

[0066] As shown in Table 1, the product obtained in Example 1 was a divinylbenzylfluorene compound with a p,p-isomer ratio of 25.2% and a total ratio of p,m-isomer and m,m-isomer of 74.8%. The divinylbenzylfluorene compound had a melting point of 138.9°C, an exothermic peak temperature of 145.2°C, a solubility in toluene of 20.7% by mass, and a solubility in MEK of 21.1% by mass.

[0067] The product obtained in Example 2 was a divinylbenzylfluorene compound with a p,p-isomer ratio of 38.2%, a melting point of 131.1°C, an exothermic peak temperature of 142.4°C, a solubility in toluene of 23.9% by mass, and a solubility in MEK of 24.1% by mass.

[0068] In contrast, the products obtained in Comparative Examples 1 and 2 were divinylbenzylfluorene compounds with a lower p,p-isomer ratio than those in Examples 1 and 2, and were inferior in solubility in toluene and MEK. Furthermore, the yields were significantly lower than those in Examples 1 and 2.

[0069] On the other hand, in Comparative Example 3, which used vinylbenzyl chloride with a meta / para molar ratio of 5 / 95, the product had a higher p,p-isomer ratio and higher solubility in toluene and MEK than in Examples 1 and 2. Specifically, the solubility measurement showed that the product was completely dissolved, i.e., the solubility was 30% by mass or more. However, in Comparative Example 3, the melting point of the product was significantly lower than in Examples 1 and 2, and the exothermic peak temperature was also lower, raising concerns about limitations on processing conditions. Furthermore, the yield was also lower than in Examples 1 and 2.

[0070] As described above, in Examples 1 and 2, the p,p-isomer ratio was higher than in Comparative Examples 1 and 2, and therefore, a divinylbenzylfluorene compound having high solubility in toluene and MEK was obtained. Furthermore, the p,p-isomer ratio was lower than in Comparative Example 3, and therefore, the compound had a high melting point. Thus, in Examples 1 and 2, both solubility in toluene and MEK and a high melting point were achieved. Furthermore, in Examples 1 and 2, a divinylbenzylfluorene compound was obtained in higher yield than in Comparative Examples 1 to 3.

[0071] In Comparative Example 4, in which DMSO was used as the reaction solvent, a solid precipitated when water and 35% by mass hydrochloric acid were added after the reaction, and therefore, operations subsequent to washing with water could not be carried out.

[0072] The curability of the divinylbenzylfluorene compounds obtained in Examples 1 and 2 was evaluated. Specifically, using a research and development test press (300 x 300 test press KVHC, manufactured by Kitagawa Seiki Co., Ltd.), the temperature was raised from 20°C to 160°C at a pressure of 10 Pa at a rate of 5°C / min, and then 10.0 g of sample was pressed at 160°C for 10 minutes to prepare a 100 mm x 100 mm x 1 mm thick plate. The obtained plate was cut into test pieces measuring 60 mm wide, 1 mm thick, and 100 mm long, and the dielectric constant (Dk) and dielectric loss tangent (Df) at 10 GHz were measured using a split cylinder resonator (manufactured by EM Lab Co., Ltd.). The results are shown in Table 2.

[0073] [Table 2] As shown in Table 2, the cured products obtained by curing the divinylbenzylfluorene compounds of Examples 1 and 2 all exhibited good dielectric properties.

[0074] The various numerical ranges described in this specification can be arbitrarily combined with their upper and lower limits, and all such combinations are considered to be preferred numerical ranges described in this specification. Furthermore, a numerical range described as "X to Y" means from X to Y.

[0075] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their omissions, substitutions, modifications, etc. are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

Claims

1. A mixture of divinylbenzylfluorene compounds represented by the following general formula (1): 【Chemistry 1】 R in general formula (1) １ , R ２ and R ３ each independently represents a hydrocarbon group having 1 to 5 carbon atoms; a, b, and c each independently represent an integer of 0 to 4; the compound contains a p,p-isomer in which both vinylbenzyl groups in general formula (1) are para-isomers, a p,m-isomer in which one vinylbenzyl group in general formula (1) is para-isomer and the other is meta-isomer, and / or an m,m-isomer in which both vinylbenzyl groups in general formula (1) are meta-isomers, and the proportion of the p,p-isomer is 20 to 50% and the total proportion of the p,m-isomer and the m,m-isomer is 50 to 80%; A mixture of divinylbenzylfluorene compounds.

2. The mixture of divinylbenzylfluorene compounds according to claim 1, which has a solubility in methyl ethyl ketone at 22°C of 20% by mass or more.

3. 2. The mixture of divinylbenzylfluorene compounds according to claim 1, having a melting point of more than 130°C and not more than 200°C.

4. A curable resin composition comprising the mixture of divinylbenzylfluorene compounds of claim 1.

5. A cured product obtained by curing the mixture of divinylbenzylfluorene compounds according to any one of claims 1 to 3 or the curable resin composition according to claim 4.

6. A method for producing a vinylbenzyl halide compound having a meta-isomer / para-isomer molar ratio of 30 / 70 to 60 / 40, comprising reacting a fluorene compound represented by the following general formula (2) with a vinylbenzyl halide compound represented by the following general formula (3) in the presence of an alkali in an aprotic polar solvent having a boiling point of less than 100°C: and precipitating the obtained product in a mixed solvent of an alcohol having 1 to 4 carbon atoms and water; 【Chemistry 2】 R in general formula (2) １ and R ２ each independently represents a hydrocarbon group having 1 to 5 carbon atoms, a and b each independently represent an integer of 0 to 4, 【Transformation 3】 R in general formula (3) ３ represents a hydrocarbon group having 1 to 5 carbon atoms, c represents an integer of 0 to 4, and X represents a halogen atom; the aprotic polar solvent is methyl ethyl ketone; the mixed solvent is a mixed solvent of methanol and water, and the amount of water in the mixed solvent is 20 to 40 mass%; A method for producing a mixture of divinylbenzylfluorene compounds.

7. 7. The method for producing a mixture of divinylbenzylfluorene compounds according to claim 6, further comprising washing the product obtained by the reaction with water, and carrying out the precipitation after washing with water.

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