An asymmetric divinylbenzylfluorene, thermosetting hydrocarbon resin, thermosetting crosslinking resin, and preparation method and application thereof

Abstract

The application belongs to the technical field of high-frequency high-speed substrate materials, and provides an asymmetric divinyl benzyl fluorene (9-(2-vinyl benzyl)-9'- (4-vinyl benzyl)-9H-fluorene, o, p-BVBF) and a thermosetting hydrocarbon resin thereof, a preparation method and application thereof, and simultaneously provides a thermosetting hydrocarbon resin of o, p-BVBF and symmetric divinyl benzyl fluorene (9, 9'-bis (4-vinyl benzyl)-9H-fluorene, p, p-BVBF) and a thermosetting crosslinking resin with o, p-BVBF and / or p, p-BVBF as a crosslinking agent and a terminal alkenyl polyphenyl ether and a preparation method and application thereof. The thermosetting hydrocarbon resin and the thermosetting crosslinking resin provided in the application both have very low dielectric constant and dielectric loss tangent and very high glass transition temperature, and have a good application prospect as a resin of a high-frequency high-speed substrate.

Description

Technical Field

[0001] This invention belongs to the field of high-frequency and high-speed substrate material technology, specifically relating to an asymmetric bisvinylbenzylfluorene, a thermosetting hydrocarbon resin, a thermosetting crosslinked modified polyphenylene ether resin, and their preparation methods and applications. Background Technology

[0002] With the rapid development of 5G / 6G communications, artificial intelligence, AR / VR, satellite navigation, and autonomous driving, electronic products require high frequencies, high speeds, and greater capacity to transmit audio, video, and data. Simultaneously, electronic products are trending towards being lighter, thinner, and smaller. To maintain higher transmission rates and signal integrity, the laminating resin materials of printed circuit boards (PCBs), the core components of electronic products, need to possess lower dielectric constants, lower dielectric loss tangents, higher glass transition temperatures, and stronger peel strength. Therefore, further improving the dielectric and thermomechanical properties of resin materials is a key technical problem that urgently needs to be solved.

[0003] Epoxy resin is a primary resin material for printed circuit boards (PCBs) due to its low cost. However, its relatively high dielectric constant and high dielectric loss tangent make it difficult to achieve a suitable low dielectric loss tangent under high-frequency signals, hindering the high-speed signal transmission required. Fluoropolymers, such as polytetrafluoroethylene (PTFE), possess low dielectric constant and low dielectric loss tangent, but as thermoplastic resins, they are difficult to process and mold for multilayer and lightweight, thin, and small PCBs. Low molecular weight vinylbenzyl or acryloyl-terminated modified polyphenylene ether (mPPO) exhibits lower dielectric constant and dielectric loss tangent. Crosslinked polyphenylene ether resins, formed by crosslinking mPPO with dienes (e.g., 1,2-bis(4-vinylphenyl)ethane, BVPE), possess high thermomechanical properties and have been used as laminate resin materials for high-end PCBs.

[0004] 9,9-Disubstituted fluorenyl hydrocarbon derivatives, due to their unique Cardo structure, possess excellent optoelectronic properties such as low dielectric constant and low dielectric loss tangent, high refractive index and transparency, as well as good heat resistance, moisture resistance and good solubility in organic solvents, and are widely used as materials for microelectronic devices.

[0005] Japanese Patent JP2003283076A discloses a mixture prepared by reacting vinylbenzyl chloride (a mixture of meta and para isomers in a 1:1 mass ratio) and allyl chloride with fluorene. The thermosetting resin of this mixture has a dielectric constant (5 GHz) of 4.0 and a dielectric loss tangent (5 GHz) of 0.0035, both of which are clearly too high. Furthermore, the presence of the allyl group on the 9-fluorene group results in a low glass transition temperature. Patent WO2022207741A1 discloses a thermosetting resin made from a mixture of vinylbenzylindene and 9,9-bisvinylbenzyl-9H-fluorene containing the meta isomer, with a dielectric loss tangent (10 GHz) of 0.00089. For resins used in high-frequency, high-speed substrates, both the dielectric constant and dielectric loss tangent remain relatively high. Meanwhile, in patent WO2022207741A1, bismaleimide was used as a crosslinking agent to increase the glass transition temperature. Bismaleimide contains polar groups, which, while increasing the glass transition temperature, leads to an increase in the dielectric loss tangent. CN1501899A discloses the reaction of a mixture of vinylbenzyl chloride (meta- and para-isomers in a 1:1 mass ratio) and fluorene to prepare a mixture of meta- and para-isomers of 9,9-bis(vinylbenzyl)-9H-fluorene with a melting point of 142℃. The dielectric constant and dielectric loss tangent (1MHz) of its thermosetting resin are 0.0013, which is obviously too high and unsuitable for use as a resin material for high-frequency and high-speed substrates.

[0006] To meet the needs of high-frequency and high-speed transmission in next-generation printed circuit laminates, further reducing the dielectric constant and dielectric loss tangent of the resin material in printed circuit boards and further increasing the glass transition temperature are key technical issues that urgently need to be addressed. Summary of the Invention

[0007] In view of the above, the present invention provides an asymmetric divinylbenzylfluorene, a thermosetting hydrocarbon resin using asymmetric divinylbenzylfluorene as a raw material, a method for preparing the resin and its application; a thermosetting hydrocarbon resin using asymmetric divinylbenzylfluorene and / or symmetrical divinylbenzylfluorene as raw materials, a method for preparing the resin and its application; and a thermosetting crosslinked polyphenylene ether resin using asymmetric divinylbenzylfluorene, symmetrical divinylbenzylfluorene, or a mixture thereof as a crosslinking agent and terminal alkenyl polyphenylene ether for crosslinking, a method for preparing the resin and its application. Since the asymmetric divinylbenzylfluorene (9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene, o,p-BVBF) provided by this invention is a nonpolar all-hydrocarbon compound, and the two asymmetric substituents of the fluorene group at the 9-position form a rigid cardo structure, it results in thermosetting hydrocarbon resins and thermosetting cross-linked polyphenylene ether resins having small dielectric loss tangents, low dielectric constants, and high glass transition temperatures, making it a promising resin material for high-frequency and high-speed substrates.

[0008] To address the aforementioned technical problems, this invention provides an asymmetric bisvinylbenzylfluorene, which is 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene having the structure shown in Formula 1:

[0009]

[0010] The thermal analysis of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene shows an endothermic melting peak of 169–175 °C, indicating a monoclinic crystal system with space group P21 / c.

[0011] This invention also provides a method for preparing the asymmetric divinylbenzylfluorene described in the above technical solution, comprising the following steps:

[0012] Fluorene, a basic reagent, a polymerization inhibitor, and a polar aprotic solvent are mixed to obtain a fluorene-containing mixed system.

[0013] The asymmetric divinylbenzylfluorene is obtained by sequentially adding 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, or by adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, to the fluorene-containing mixed system to carry out a nucleophilic substitution reaction.

[0014] Preferably, the alkaline reagent includes one or more of alkali metal hydroxides, alkali metal alkoxides, sodium hydride, and potassium hydride;

[0015] The polymerization inhibitor includes one or more of nitromethane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide, and 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide.

[0016] The polar aprotic solvents include dimethyl sulfoxide, sulfolane, N,N-dimethylformamide, N,N-diethylformamide, acetonitrile, or hexamethylphosphoramide;

[0017] The molar ratio of fluorene to the alkaline reagent is 1:1.8 to 5;

[0018] The molar ratio of 2-vinylbenzyl chloride to 4-vinylbenzyl chloride is 2-6:4-8;

[0019] The total molar amount of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride and the molar ratio of fluorene are 1.8 to 2.2:1.

[0020] Preferably, the nucleophilic substitution reaction is carried out at a temperature of 20–50°C for a time of 2–8 hours.

[0021] This invention also provides a method for preparing the asymmetric divinylbenzylfluorene described in the above technical solution, comprising the following steps:

[0022] Fluorene, a basic reagent, a polymerization inhibitor, a phase transfer catalyst, and a solvent were mixed to obtain a fluorene-containing phase transfer catalytic system.

[0023] The asymmetric divinylbenzylfluorene is obtained by sequentially adding 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, or by adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, to the fluorene-containing phase transfer catalytic system under phase transfer catalytic conditions for nucleophilic substitution reaction.

[0024] Preferred alkaline reagents include alkali metal hydroxides and / or alkali metal alkoxides;

[0025] The polymerization inhibitor includes one or more of nitromethane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide, and 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide.

[0026] The phase transfer catalyst includes one or more of quaternary ammonium salts, quaternary phosphorus salts, and polyethylene glycol;

[0027] The mass of the phase transfer catalyst is 5-25% of the mass of fluorene;

[0028] The molar ratio of fluorene to the alkaline reagent is 1:1.8 to 5;

[0029] The molar ratio of 2-vinylbenzyl chloride to 4-vinylbenzyl chloride is 2-6:4-8;

[0030] The total molar amount of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride and the molar ratio of fluorene are 1.8 to 2.2:1.

[0031] Preferably, the nucleophilic substitution reaction under the phase transfer catalytic conditions is carried out at a temperature of 25–75°C for a time of 8–18 h.

[0032] The present invention also provides thermosetting resins, including thermosetting hydrocarbon resins and / or thermosetting crosslinking resins, wherein the thermosetting hydrocarbon resins include thermosetting hydrocarbon resins prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene as a raw material and / or thermosetting hydrocarbon resins prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene and 9,9'-bis(4-vinylbenzyl)-9H-fluorene as raw materials;

[0033] The thermosetting crosslinked resin includes a thermosetting crosslinked resin prepared using a crosslinking agent and a terminal alkenyl polyphenylene ether as raw materials; the crosslinking agent includes 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene and / or 9,9'-bis(4-vinylbenzyl)-9H-fluorene; the terminal alkenyl polyphenylene ether has a structure shown in any one of Formulas 2 to 5;

[0034]

[0035] The 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene is the asymmetric divinylbenzylfluorene described in the above technical solution or the asymmetric divinylbenzylfluorene prepared by the preparation method described in the above technical solution.

[0036] The present invention also provides a method for preparing the thermosetting resin described in the above technical solution, comprising the following steps:

[0037] The raw materials and initiator were dissolved in toluene to obtain a mixed solution;

[0038] After removing toluene from the mixed solution, the solution is subjected to melt thermosetting to obtain the thermosetting resin.

[0039] The present invention also provides the application of the thermosetting resin described in the above technical solution or the thermosetting resin prepared by the preparation method described in the above technical solution as a resin material for high-frequency and high-speed substrates.

[0040] This invention provides an asymmetric divinylbenzylfluorene having the structure shown in Formula 1: The thermal analysis of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene shows a melting endothermic peak of 169–175 °C, indicating a monoclinic crystal system with space group P21 / c. The bisvinylbenzylfluorene (9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) provided by this invention has an asymmetric structure and is a nonpolar all-hydrocarbon compound. Simultaneously, the two asymmetric substituents at the 9-position fluorene group constitute a rigid cordo structure. This results in thermosetting resins prepared using the asymmetric bisvinylbenzylfluorene provided by this invention as a raw material exhibiting characteristics such as a small dielectric loss tangent, low dielectric constant, high glass transition temperature, and ease of processing, making it suitable as a resin material for high-frequency and high-speed substrates. Attached Figure Description

[0041] Figure 1 A schematic diagram of the process for synthesizing asymmetric divinylbenzylfluorene via nucleophilic substitution reaction;

[0042] Figure 2 The HPLC spectrum of o,p-BVBF prepared in Example 1;

[0043] Figure 3 o,p-BVBF prepared in Example 1 1 HNMR spectrum;

[0044] Figure 4 o,p-BVBF prepared in Example 1 13 CNMR spectrum;

[0045] Figure 5 The thermal analysis DSC spectrum of o,p-BVBF prepared in Example 1;

[0046] Figure 6 The single-crystal structure diagram of o,p-BVBF prepared in Example 1;

[0047] Figure 7 The cell packing diagram is for o,p-BVBF prepared in Example 1. Detailed Implementation

[0048] This invention synthesizes an asymmetric bisvinylbenzylfluorene, which is 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) having the structure shown in Formula 1:

[0049]

[0050] The thermal analysis of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene shows an endothermic melting peak of 169–175 °C, indicating a monoclinic crystal system with space group P21 / c.

[0051] In this invention, the "asymmetric" in "asymmetric bisvinylbenzylfluorene" refers to the presence of different substituents at the 9-position of the fluorene group.

[0052] As a specific embodiment of the present invention, the thermal analysis melting endothermic peak of the 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene is 169-175℃, and can be 171-173℃; the purity (HPLC) of the asymmetric divinylbenzylfluorene can be >98.5%.

[0053] The present invention synthesized the 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) using two methods.

[0054] The present invention also provides a first method for preparing the asymmetric divinylbenzylfluorene described in the above technical solution, comprising the following steps:

[0055] Fluorene, a basic reagent, a polymerization inhibitor, and a polar aprotic solvent are mixed to obtain a fluorene-containing mixed system.

[0056] The asymmetric divinylbenzylfluorene is obtained by sequentially adding 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, or by adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, to the fluorene-containing mixed system to carry out a nucleophilic substitution reaction.

[0057] In one specific embodiment of the present invention, the alkaline reagent may include one or more of alkali metal hydroxides, alkali metal alkoxides, sodium hydride, and potassium hydride, specifically a mixture of alkali metal hydroxides and alkali metal alkoxides, alkali metal hydroxides, alkali metal alkoxides, sodium hydride, or potassium hydride; the alkali metal hydroxide may be sodium hydroxide or potassium hydroxide; the alkali metal alkoxide may be potassium tert-butoxide or sodium tert-butoxide; the molar ratio of fluorene to the alkaline reagent may be 1:1.8 to 5, or 1:2 to 4.

[0058] In one specific embodiment of the present invention, the polymerization inhibitor may include one or more of the following: nitromethane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide, and 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide (701 polymerization inhibitor), specifically nitromethane. Alkane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide compound or 701 polymerization inhibitor; the amount of the polymerization inhibitor can be 0.01-0.5% of the mass of vinylbenzyl chloride, or 0.1-0.4%; the vinylbenzyl chloride is 2-vinylbenzyl chloride and 4-vinylbenzyl chloride.

[0059] In one specific embodiment of the present invention, the polar aprotic solvent includes dimethyl sulfoxide, sulfolane, N,N-dimethylformamide, N,N-diethylformamide, acetonitrile, or hexamethylphosphoramide; the present invention does not have a special limitation on the amount of the polar aprotic solvent used, as long as it can mix the materials evenly.

[0060] The present invention does not have special requirements for the mixing of fluorene, basic reagent, polymerization inhibitor and polar aprotic solvent, as long as they can be mixed evenly.

[0061] In this invention, 2-vinylbenzyl chloride is first added dropwise to the fluorene-containing mixed system to generate a monosubstituted 9-(2-vinylbenzyl)fluorene intermediate, followed by the dropwise addition of 4-vinylbenzyl chloride. Compared to directly adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, the yield of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) is significantly increased. If 4-vinylbenzyl chloride is added dropwise first, followed by the addition of 2-vinylbenzyl chloride... The reaction of 2-vinylbenzyl chloride mainly yields 9,9'-bis-(4-vinylbenzyl)fluorene (p,p-BVBF), while the yield of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) is very low. This is because 2-vinylbenzyl chloride is much more sterically hindered than 4-vinylbenzyl chloride in the reaction, and it is difficult to introduce 2-vinylbenzyl when there is already a 4-vinylbenzyl group on the fluorene group at the 9-position.

[0062] In one specific embodiment of the present invention, the molar ratio of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride can be 2 to 6:4 to 8, specifically 2:8, 3:7, 4:6, 5:5 or 6:4; the total molar amount of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride and the molar ratio of fluorene can be 1.8 to 2.2:1, specifically 2:1.

[0063] In one specific embodiment of the present invention, the temperature of the nucleophilic substitution reaction can be 20–50°C or 30–40°C; the time of the nucleophilic substitution reaction can be 2–8 hours or 3–7 hours. In another specific embodiment of the present invention, the nucleophilic substitution reaction can be carried out under stirring conditions. The present invention does not impose any particular limitation on the stirring.

[0064] As a specific embodiment of the present invention, the nucleophilic substitution reaction may further include:

[0065] The system following the nucleophilic substitution reaction was mixed with ice water and then separated into solid and liquid phases to obtain a solid.

[0066] The solid was washed with water and then subjected to pulping, filtration, recrystallization and drying to obtain the asymmetric divinylbenzylfluorene.

[0067] In one specific embodiment of the present invention, the volume ratio of the system after the nucleophilic substitution reaction to ice water can be 3:8–12, or 3:10–11; the solid-liquid separation can be filtration; the present invention has no special requirements on the number of water washings, as long as the pH of the filtrate after water washing is neutral. In one specific embodiment of the present invention, the solvent for pulping can be an alcohol solvent; the alcohol solvent can include methanol, ethanol, or isopropanol; the pulping temperature can be 0–40°C, or 10–30°C. The present invention has no special limitations on the filtration, and conventional methods in the art can be used. In one specific embodiment of the present invention, the solvent for recrystallization can include toluene, ethylbenzene, xylene, or cumene; the drying can be vacuum drying, and the vacuum drying temperature can be 70–90°C, or 75–80°C; the present invention has no special requirements on the vacuum drying time, as long as the solvent is removed.

[0068] The present invention also provides a second method for preparing the asymmetric divinylbenzylfluorene described in the above technical solution, comprising the following steps:

[0069] Fluorene, a basic reagent, a polymerization inhibitor, a phase transfer catalyst, and a solvent were mixed to obtain a fluorene-containing phase transfer catalytic system.

[0070] The asymmetric divinylbenzylfluorene is obtained by sequentially adding 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, or by adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, to the fluorene-containing phase transfer catalytic system under phase transfer catalytic conditions for nucleophilic substitution reaction.

[0071] In one specific embodiment of the present invention, the alkaline reagent may include alkali metal hydroxides and / or alkali metal alkoxides; specifically, it may be a mixture of alkali metal hydroxides and alkali metal alkoxides, alkali metal hydroxides or alkali metal alkoxides; the alkali metal hydroxide may be sodium hydroxide or potassium hydroxide; the alkali metal alkoxide may be potassium tert-butoxide or sodium tert-butoxide; the molar ratio of fluorene to the alkaline reagent may be 1:1.8 to 5, or 1:2 to 4.

[0072] In one specific embodiment of the present invention, the polymerization inhibitor may include one or more of the following: nitromethane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide, and 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide (701 polymerization inhibitor), specifically nitro... Methane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide compound, or 701 polymerization inhibitor; the amount of the polymerization inhibitor is 0.01-0.5% of the mass of vinylbenzyl chloride, and may also be 0.1-0.4%; the vinylbenzyl chloride is 2-vinylbenzyl chloride and 4-vinylbenzyl chloride.

[0073] In one specific embodiment of the present invention, the phase transfer catalyst may include one or more of quaternary ammonium salts, quaternary phosphonium salts, and polyethylene glycol, specifically quaternary ammonium salts, quaternary phosphonium salts, or polyethylene glycol; the quaternary ammonium salt may be tetrabutylammonium bromide (TBAB), tetrabutylammonium chloride (TBAC), benzyltriethylammonium bromide (BTEAB), benzyltriethylammonium chloride (BTEAC), hexadecyltriethylammonium bromide (HTEAB), or hexadecyltriethylammonium chloride (HTEAC); the quaternary phosphonium salt may be hexadecyltributylphosphonium bromide (HTBPB), hexadecyltributylphosphonium chloride (HTBPC), tetrabutylphosphonium bromide (TBPB), tetrabutylphosphonium chloride (TBPC), tetraphenylphosphonium bromide (TPPB), or tetraphenylphosphonium chloride (TPPC); the polyethylene glycol may be PEG-400, PEG-600, or PEG-800. In one specific embodiment of the present invention, the mass of the phase transfer catalyst can be 5-25% of the mass of fluorene, or it can be 10-20%.

[0074] As a specific embodiment of the present invention, the nucleophilic substitution reaction under the phase transfer catalysis conditions can be a nucleophilic substitution reaction under liquid-liquid phase transfer catalysis conditions or a nucleophilic substitution reaction under solid-liquid phase transfer catalysis conditions.

[0075] As a specific embodiment of the present invention, when the nucleophilic substitution reaction under the phase transfer catalytic conditions is a reaction under solid-liquid phase transfer catalytic conditions, the solvent can be an organic solvent, which may include dimethyl sulfoxide, sulfolane, N,N-dimethylformamide, N,N-diethylformamide, acetonitrile or hexamethylphosphoramide.

[0076] In one specific embodiment of the present invention, when the nucleophilic substitution reaction under the phase transfer catalytic conditions is a reaction under liquid-liquid phase transfer catalytic conditions, the solvent can be a mixture of aromatic hydrocarbons and water or a mixture of alkanes and water; the aromatic hydrocarbons can be toluene, xylene, ethylbenzene or cumene; the alkanes can be n-hexane, n-heptane, cyclohexane, methylcyclopentane or petroleum ether.

[0077] In this invention, 2-vinylbenzyl chloride is added dropwise to generate a monosubstituted 9-(2-vinylbenzyl)fluorene intermediate, followed by the dropwise addition of 4-vinylbenzyl chloride. Compared to directly adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, the yield of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) is significantly increased. If 4-vinylbenzyl chloride is added dropwise first, followed by 2-vinylbenzyl chloride, the reaction mainly yields 9,9'-bis-(4-vinylbenzyl)fluorene (p,p-BVBF), while 9-( The yield of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) is very low. This is because the steric hindrance of 2-vinylbenzyl chloride is much greater than that of 4-vinylbenzyl chloride in the reaction. When there is already a 4-vinylbenzyl group on the fluorene group at the 9-position, it is difficult to introduce the 2-vinylbenzyl group. Therefore, 2-vinylbenzyl chloride is added dropwise first, and after reacting for a period of time, 4-vinylbenzyl chloride is added dropwise to carry out the reaction, which is beneficial to improve the yield of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF).

[0078] In one specific embodiment of the present invention, the molar ratio of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride can be 2 to 6:4 to 8, specifically 2:8, 3:7, 4:6, 5:5 or 6:4; the total molar amount of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride and the molar ratio of fluorene can be 1.8 to 2.2:1, specifically 2:1.

[0079] In one specific embodiment of the present invention, the temperature of the nucleophilic substitution reaction under the phase transfer catalytic conditions can be 25–75°C, or even 30–70°C; the time of the nucleophilic substitution reaction under the phase transfer catalytic conditions can be 8–18 h, or even 10–15 h. In another specific embodiment of the present invention, the reaction under the phase transfer catalytic conditions must be carried out under good stirring conditions.

[0080] As a specific embodiment of the present invention, the nucleophilic substitution reaction under the phase transfer catalytic conditions may further include:

[0081] After the nucleophilic substitution reaction under the phase transfer catalytic conditions was carried out by distillation to remove the solvent, water and toluene were added for extraction, and the organic phase was obtained.

[0082] The organic phase was concentrated and then washed, pulped, filtered, recrystallized and dried in sequence to obtain the asymmetric divinylbenzylfluorene.

[0083] In one specific embodiment of the present invention, the volume ratio of the extraction water to toluene can be 1:0.8-1.2, or even 1:1; the concentration can be vacuum distillation, and the present invention has no special requirements for the vacuum distillation, as long as the solvent can be removed. In one specific embodiment of the present invention, the washing solvent can be a saturated ammonium chloride solution, and the present invention has no special requirements for the number of washings, as long as the pH of the washing solution after washing is neutral. In one specific embodiment of the present invention, the pulping solvent can be an alcohol solvent with five or fewer carbon atoms; the alcohol solvent with five or fewer carbon atoms includes methanol, ethanol, or isopropanol; the pulping temperature can be 0-40°C, or even 10-30°C. The present invention has no special limitations on the filtration, and conventional methods in the art can be used. In one specific embodiment of the present invention, the recrystallization solvent can include toluene, ethylbenzene, xylene, or isopropylbenzene; the drying can be vacuum drying, and the vacuum drying temperature can be 70-90°C, or even 75-80°C; the present invention has no special requirements for the vacuum drying time, as long as the solvent can be removed.

[0084] Figure 1 This is a schematic diagram of the process for synthesizing asymmetric divinylbenzylfluorene via nucleophilic substitution reaction.

[0085] The present invention also provides thermosetting resins, including thermosetting hydrocarbon resins and / or thermosetting crosslinking resins, wherein the thermosetting hydrocarbon resins include thermosetting hydrocarbon resins prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene as a raw material and / or thermosetting hydrocarbon resins prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene and 9,9'-bis(4-vinylbenzyl)-9H-fluorene as raw materials;

[0086] The thermosetting crosslinked resin includes a thermosetting crosslinked resin prepared using a crosslinking agent and a terminal alkenyl polyphenylene ether as raw materials; the crosslinking agent includes 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene and / or 9,9'-bis(4-vinylbenzyl)-9H-fluorene; the terminal alkenyl polyphenylene ether has a structure shown in any one of Formulas 2 to 5;

[0087]

[0088] The 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene is the asymmetric divinylbenzylfluorene described in the above technical solution or the asymmetric divinylbenzylfluorene prepared by the preparation method described in the above technical solution.

[0089] As a specific embodiment of the present invention, the thermosetting hydrocarbon resin prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene as the raw material has a low dielectric constant (Dk(10GH) 2.8), a low dielectric loss tangent (Df(10GH) 0.00030), and a high glass transition temperature (Tg 360℃).

[0090] In one specific embodiment of the present invention, the molar percentage of o,p-BVF in the raw materials of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVF) and 9,9'-bis(4-vinylbenzyl)-9H-fluorene (p,p-BVBF) can be 10-60%, or even 25-50%. In this invention, 9,9'-bis(4-vinylbenzyl)-9H-fluorene is a symmetrical bisvinylbenzylfluorene, where symmetry refers to the presence of identical substituents at the 9-position of the fluorene group. The structural formula of 9,9'-bis(4-vinylbenzyl)-9H-fluorene is as follows:

[0091] As a specific embodiment of the present invention, the thermosetting hydrocarbon resin prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene and 9,9'-bis(4-vinylbenzyl)-9H-fluorene as raw materials has the properties of very low dielectric constant, very low dielectric loss tangent, and relatively high glass transition temperature. For example, when the molar ratio of o,p-BVF and p,p-BVBF is 1:1, the resulting thermosetting hydrocarbon resin has a dielectric constant of Dk(10GH) 2.8, a dielectric loss tangent of Df(10GH) 0.00042, and a glass transition temperature of 352°C.

[0092] In one specific embodiment of the present invention, the number average molecular weight (Mn) of the terminal alkenyl polyphenylene ether in the thermosetting crosslinking resin prepared by using a crosslinking agent and terminal alkenyl polyphenylene ether as raw materials can be 1800-2300. The terminal alkenyl polyphenylene ether can specifically be terminal vinyl benzyl modified polyphenylene ether, and the structural formula of the terminal vinyl benzyl modified polyphenylene ether is as follows;

[0093]

[0094] As a specific embodiment of the present invention, the preparation method of the terminal vinyl benzyl modified polyphenylene ether may include the following steps:

[0095] 2,6-Dimethylphenol, diphenol and catalyst were subjected to oxidative coupling copolymerization under oxygen conditions to obtain hydroxyl polyphenylene ether;

[0096] The hydroxyl polyphenylene ether and vinyl benzyl chloride were reacted under phase transfer conditions and then precipitated with methanol to obtain the terminal vinyl benzyl modified polyphenylene ether.

[0097] In one specific embodiment of the present invention, the catalyst includes a copper amine complex catalyst; the copper amine complex catalyst includes N,N'-tetra-tert-butylethylenediamine, N-methylbutylamine, cuprous bromide, cuprous chloride, cupric chloride, or cupric bromide; the number average molecular weight of the hydroxyl polyphenylene ether can be 1600-2000.

[0098] In one specific embodiment of the present invention, when 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene and 9,9'-bis(4-vinylbenzyl)-9H-fluorene are used as crosslinking agents to prepare thermosetting crosslinked resins, the mass percentage of the crosslinking agent in the raw materials can be 10-50%, or even 20-40%; the molar percentage of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVF) in the crosslinking agent can be 10-60%, or even 25-50%.

[0099] The thermosetting resin provided by this invention has a low dielectric constant, a low dielectric loss tangent, and an increased glass transition temperature, making it a promising resin material for high-frequency substrates.

[0100] The present invention also provides a method for preparing the thermosetting resin described in the above technical solution, comprising the following steps:

[0101] The raw materials and initiator were dissolved in toluene to obtain a mixed solution;

[0102] After removing toluene from the mixed solution, the solution is subjected to melt thermosetting to obtain the thermosetting resin.

[0103] In one specific embodiment of the present invention, the initiator may include peroxides, which may include di-tert-butyl peroxide, tert-butyl hydroperoxide, cumene peroxide, benzoyl tert-butyl peroxide, di(tert-butylperoxy)isopropylbenzene, dibenzoyl peroxide, di(4-methylbenzoyl peroxide), dilauroyl peroxide, 1,1-di(tert-butylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 3,3,5,7,7-pentamethyl-1,2,4-trioxane (T311), tert-butyl peroxide-2-ethylhexanoate, and tert-butylperoxy-2-hexylhexane carbonate; the mass ratio of the raw materials to the initiator may be 1:0.001 to 0.008, or 1:0.003 to 0.005.

[0104] As a specific embodiment of the present invention, the method for removing toluene from the mixed solution can be vacuum distillation.

[0105] In one specific embodiment of the present invention, the temperature of the melt heat curing can be 200-240°C or 210-230°C; the pressure of the melt heat curing can be 70-80 mmHg or 75-78 mmHg; and the time of the melt heat curing can be 80-120 min or 90-110 min.

[0106] The present invention also provides the application of the thermosetting resin described in the above technical solution or the thermosetting resin prepared by the preparation method described in the above technical solution as a resin material for high-frequency and high-speed substrates.

[0107] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0108] The analytical instruments and analytical testing methods used in the examples are as follows:

[0109] 1. Purity determination method (HPLC): Agilent 1260 high-performance liquid chromatograph (HPLC); column type: Kromasil 100-5 C18 250cm×4.6mm; mobile phase: acetonitrile / methanol volume ratio = 9:1; flow rate: 0.8mL / min; detection wavelength: 254nm; injection volume: 2μL; pump mode: binary high-pressure gradient.

[0110] 2. Thermal analysis method: DSC was measured using a Pyris1 thermal analyzer (PerkinElemer), with a heating range of 50–200 °C and a heating rate of 10 °C / min.

[0111] 3. Nuclear magnetic resonance spectroscopy determination: Bruker AV 400 nuclear magnetic resonance spectrometer, DMSO-d6 as solvent, TMS as internal standard.

[0112] 4. Single crystal structure determination: Bruker D8 Venture single crystal diffractometer, JY / T0588-2020 General Rules for Molecular Structure Analysis.

[0113] 5. Determination of dielectric constant Dk (10 GHz) and dielectric loss tangent Df (10 GHz): The molten sample casting method was used (thermosetting conditions: temperature 220℃, pressure 70–80 mmHg, time 100 min). Resin sheets of 80 mm × 80 mm × 0.4 mm were prepared and measured at 10 GHz using an Agilent N5230A vector network analyzer (SPDR).

[0114] 6. Polymer molecular weight determination: Agilent 1260 gel permeation chromatography system (USA), tetrahydrofuran as mobile phase, polystyrene as standard.

[0115] 7. Polymer glass transition temperature determination: determined by Perkin Elemer Differential Scanning Calorimeter dsc 4000 instrument.

[0116] The 2-vinylbenzyl chloride (HPLC purity 99.0%), 4-vinylbenzyl chloride (HPLC purity 99.5%), and 1,2-bis(4-vinylphenyl)ethane (BVPE) (HPLC purity 99.5%) in the examples were all produced by Shandong Xingshun New Materials Co., Ltd.

[0117] Examples 1-7 prepared 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), and Examples 8-13 prepared thermosetting resins.

[0118] Example 1

[0119] 300 mL of anhydrous dimethyl sulfoxide, 1.10 mol of potassium tert-butoxide, and 0.3 g of 701 polymerization inhibitor were added to a reaction flask. After stirring under a nitrogen stream for 30 min, 0.5 mol of fluorene was added and stirred until dissolved. Then, 0.4 mol of 2-chloromethylstyrene was added dropwise. The reaction was carried out at 30–35 °C and 350 r / min for 1.0 h with stirring. Then, 0.6 mol of 4-chloromethylstyrene was added dropwise with stirring, and the reaction was continued for 2.5 h with stirring. The solution after the reaction was slowly added to 1000 mL of ice water. The precipitated solid was filtered and washed with water until the filtrate was neutral. The solid was slurried twice with 500 mL of methanol (30 °C). The obtained solid was recrystallized twice with toluene. The obtained solid was dried under vacuum at 80 °C to constant weight to obtain 144.5 g of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), with a yield of 72.5%.

[0120] o,p-BVBF is a white crystalline solid. The prepared o,p-BVBF was detected by high-performance liquid chromatography (HPLC), and the HPLC chromatogram was obtained, as shown below. Figure 2 As shown in Table 1, the peak information is obtained from high-performance liquid chromatography (HPLC). According to the HPLC detection results, the HPLC purity of o,p-BVBF is 99.15%.

[0121] The prepared o,p-BVBF was subjected to nuclear magnetic resonance detection to obtain... 1 HNMR spectrum and 13 C NMR spectrum, such as Figures 3-4 As shown, where Figure 3 For o,p-BVBF 1 HNMR spectrum Figure 4 For o,p-BVBF 13 C10 NMR spectrum.

[0122] 1 ¹H NMR (400MHz, DMSO-d6) δ: 3.43 (s, 2H, CH₂), 3.54 (s, 2H, CH₂), 5.03–5.08 (m, 2H, 2× olefinic hydrogen), 5.40–5.59 (m, 2H, 2× olefinic hydrogen), 6.40–6.42 (m, 1H, 1× olefinic hydrogen), 6.49 (d, 2H, 2× benzene ring hydrogen), 6. 70-6.77 (m, 2H, 2×benzene ring hydrogen), 6.97-7.01 (m, 3H, 2×benzene ring hydrogen, 1×olefinic hydrogen), 6.87-6.95 (m, 1H, 1×benzene ring hydrogen), 7.05-7.20 (m, 4H, 4×fluorene ring hydrogen), 7.22-7.25 (m, 1H, 1×benzene ring hydrogen), 7.33-7.58 (m, 4H, 4×fluorene ring hydrogen).

[0123] 13C NMR (100MHz, DMSO-d6) δ: 40.9 (CH2), 43.3 (CH2), 56.7 (9-fluorene C), 113.2, 115.0, 119.7, 124.7, 124.9, 125.3, 126.3, 126.5, 126.7, 127.1, 129.9, 130.9, 134.3, 134.9, 135.1, 136.3, 136.9, 137.0, 140.3, 148.0 (benzene ring C, fluorene ring C, vinyl C).

[0124] 1 HNMR spectrum and 13 The C NMR spectrum is in perfect agreement with the structure of o,p-BVBF.

[0125] The prepared o,p-BVBF was analyzed using a Pyris1 thermal analyzer, and the DSC spectrum was obtained as follows: Figure 5 As shown. By Figure 5 It can be seen that the melting point of o,p-BVBF is 171.4~172.7℃.

[0126] Figure 6 This is a single crystal structure diagram of o,p-BVBF, where ○ represents H atoms; Figure 7 The cell packing diagram of o,p-BVBF is shown. The crystallographic parameters of o,p-BVBF are shown in Table 2, and the bond lengths and bond angles of o,p-BVBF are shown in Table 3. The single-crystal structure determination results further confirm the molecular structure of o,p-BVBF.

[0127] Table 1. HPLC peak information for p-BVBF

[0128]

[0129]

[0130] Table 2. Crystallographic parameters of o, p-BVBF

[0131]

[0132] Table 3. Bond lengths of o, p-BVBF Bond angle [°]

[0133]

[0134]

[0135] Example 2

[0136] 300 mL of anhydrous dimethyl sulfoxide, 1.10 mol of potassium tert-butoxide, and 0.3 g of 701 polymerization inhibitor were added to a reaction flask. After stirring under a nitrogen stream for 30 min, 0.5 mol of fluorene was added and stirred until dissolved. Then, 0.3 mol of 2-chloromethylstyrene was added dropwise. The reaction was carried out at 35 °C and 350 r / min for 1.0 h. Then, 0.7 mol of 4-chloromethylstyrene was added dropwise with stirring, and the reaction was continued for 2.5 h. The solution after the reaction was slowly added to 1000 mL of ice water, and the precipitated solid was filtered. The solid was washed with water until the filtrate was neutral. The solid was slurried twice with 500 mL of methanol (30 °C). The obtained solid was recrystallized twice with toluene. The obtained solid was dried under vacuum at 80 °C to constant weight to obtain 110.8 g of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), white crystals with a purity (HPLC) of 99.1% and a yield of 55.6%.

[0137] Example 3

[0138] Add 300 mL of anhydrous dimethyl sulfoxide, 1.10 mol of potassium tert-butoxide, and 0.3 g of 701 polymerization inhibitor to a reaction flask. Stir under a nitrogen stream for 30 min, then add 0.5 mol of fluorene. After stirring to dissolve, add 0.5 mol of 2-chloromethylstyrene dropwise. React at 35 °C and 350 rpm for 1.0 h with stirring. Then add 0.5 mol of 4-chloromethylstyrene dropwise with stirring, and continue stirring for 2.5 h. Slowly add the reaction solution to 1000 mL of ice water, filter the precipitated solid, wash with water until the filtrate is neutral, and slurry the solid twice with 500 mL of methanol (30 °C). Recrystallize the obtained solid twice with toluene, and dry the solid under vacuum at 80 °C to constant weight to obtain 126.7 g. 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), white crystals, purity (HPLC) 99.2%, yield 63.6%.

[0139] Example 4

[0140] 300 mL of anhydrous dimethyl sulfoxide, 1.10 mol of potassium tert-butoxide, and 0.3 g of 701 polymerization inhibitor were added to a reaction flask. After stirring under a nitrogen stream for 30 min, 0.5 mol of fluorene was added and stirred until dissolved. Then, a mixed solution of 0.4 mol of 2-chloromethylstyrene and 0.6 mol of 4-chloromethylstyrene was added dropwise. The reaction was carried out at 35 °C and 350 r / min for 3.5 h. The reaction solution was then slowly added to 1000 mL of ice water. The precipitated solid was filtered and washed with water until the filtrate was neutral. The solid was slurried twice with 500 mL of methanol (30 °C). The filtered solid was recrystallized twice with toluene. The solid was dried under vacuum at 80 °C to constant weight to obtain 90.6 g of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), white crystals with a purity (HPLC) of 98.5% and a yield of 45.5%.

[0141] Example 5

[0142] Add 500 mL of toluene and 0.5 mol of fluorene to a reaction flask and stir to dissolve. Add 180 g of a pre-prepared 50% sodium hydroxide solution, 8.5 g of tetrabutylammonium bromide (TBAB), and 0.3 g of 701 polymerization inhibitor while stirring. Add 0.4 mol of 2-chloromethylstyrene dropwise at 40 °C under a nitrogen atmosphere and stirring at 350 r / min for 4.0 h. Then add 0.6 mol of 4-chloromethylstyrene dropwise while stirring and continue the reaction for 10 h. Cool to room temperature, slowly add 500 mL of water while stirring, separate the organic phase, and wash twice with 500 mL of water each time. Wash the organic phase with 500 mL of saturated ammonium chloride aqueous solution, then wash with water until neutral. Separate the organic phase and evaporate the toluene under reduced pressure. Pulverize the solid twice with 500 mL of methanol (30 °C). Recrystallize the obtained solid twice with toluene and dry the solid under vacuum at 80 °C to constant weight, yielding 124.3 g. 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), white crystals, purity (HPLC) 98.5%, yield 62.4%.

[0143] Example 6

[0144] Add 500 mL of toluene and 0.5 mol of fluorene to a reaction flask and stir to dissolve. Add 180 g of a pre-prepared 50% sodium hydroxide solution, 8.5 g of tetrabutylammonium bromide (TBAB), and 0.3 g of 701 polymerization inhibitor while stirring at 40 °C. Add a mixed solution of 0.5 mol 2-chloromethylstyrene and 0.5 mol 4-chloromethylstyrene dropwise under nitrogen flow and stirring. React for 14.0 h at 350 rpm. Cool to room temperature, slowly add 500 mL of water while stirring, separate the organic phase, and wash twice with 500 mL of water each time. Wash the organic phase with 500 mL of saturated ammonium chloride aqueous solution, followed by water washing at neutral pH. Separate the organic phase and evaporate the toluene under reduced pressure. Pulverize the solid twice with 500 mL of methanol (30 °C). Recrystallize the obtained solid twice with toluene after filtration. Dry the obtained solid under vacuum at 80 °C to constant weight to obtain 84.7 g. 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), white crystals, purity (HPLC) 98.5%, yield 42.5%.

[0145] Example 7

[0146] Add 500 mL of acetonitrile, 1.2 mol of potassium hydroxide powder, 30 g of PEG-400, and 0.3 g of 701 polymerization inhibitor to a reaction flask. Add 0.5 mol (83 g) of fluorene under stirring. Add 0.4 mol of 2-chloromethylstyrene dropwise under nitrogen flow and stirring at 40 °C. React at 350 r / min for 4.0 h. Then add 0.6 mol of 4-chloromethylstyrene dropwise under stirring, and continue stirring for another 8.0 h. Stop the reaction, evaporate the acetonitrile, add 500 mL of water and 500 mL of toluene, and allow the layers to separate. Wash the organic phase with 500 mL of saturated ammonium chloride solution and water until neutral. Evaporate the toluene under reduced pressure. Pulverize the solid twice with 500 mL of methanol (30 °C). Recrystallize the obtained solid twice with toluene. Dry the obtained solid under vacuum at 80 °C to constant weight to obtain 106.6 g. 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), white crystals, purity (HPLC) 98.7%, yield 53.5%.

[0147] Example 8

[0148] 20g of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) prepared in Example 1 and 0.1g of T311 peroxide initiator were dissolved in 50g of toluene; the solvent was removed under reduced pressure, and then a thermosetting hydrocarbon resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70~80mmHg, time 100min); the glass transition temperature was determined; the prepared resin was made into 80mm×80mm×0.4mm thin sheets, and the dielectric constant and dielectric loss tangent of the sample at a frequency of 10GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0149] Example 9

[0150] Add 500 mL of acetonitrile, 1.4 mol of potassium tert-butoxide, 30 g of PEG-400, and 0.5 g of polymerization inhibitor 701 to a reaction flask. Then, under stirring conditions with a nitrogen stream, add 0.6 mol of fluorene and 1.4 mol of... 4-Vinylbenzyl chloride (HPLC, 99%) was reacted at 30–35 °C and 350 rpm with stirring until the fluorene content was <1 wt% according to HPLC analysis. The reaction was stopped, acetonitrile was evaporated, and 500 mL of water and 500 mL of toluene were added. The phases were separated, and the organic phase was washed with saturated ammonium chloride solution and water three times (500 mL each time) until neutral. Toluene was evaporated under reduced pressure, and a mixed solvent of toluene and methanol in a volume ratio of 1:0.3 was added. The mixture was heated until completely dissolved, and the temperature was lowered to 5 °C at a rate of 0.5 °C / min to crystallize. The solid fraction was filtered and dried at 90 °C to constant weight to obtain 9,9-bis(2-vinylbenzyl)-9H-fluorene (p,p-BVBF), white crystals with a melting point of 118.5–120.0 °C and a purity (HPLC) of 99.5%.

[0151] 20 g of 9,9-bis(4-vinylbenzyl)-9H-fluorene (p,p-BVBF) and 0.1 g of T311 peroxide initiator were dissolved in 50 g of toluene. The solvent was removed under reduced pressure, and then a thermosetting hydrocarbon resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70~80mmHg, time 100min). The glass transition temperature was determined. The prepared resin was made into 80mm×80mm×0.4mm thin films, and the dielectric constant and dielectric loss tangent of the samples at a frequency of 10GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0152] Example 10

[0153] 9,9-bis(2-vinylbenzyl)-9H-fluorene (p,p-BVBF) was prepared according to the method of Example 9. It is a white crystal with a melting point of 118.5-120.0 °C and a purity (HPLC) of 99.5%.

[0154] 10 g of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) and 10 g of 9,9-bis(4-vinylbenzyl)-9H-fluorene (p,p-BVBF) and 0.1 g of T311 peroxide initiator prepared in Example 1 were dissolved in 50 g of toluene. The solvent was removed under reduced pressure, and then a thermosetting hydrocarbon resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70-80 mmHg, time 100 min). The glass transition temperature was determined. The prepared resin was made into 80 mm × 80 mm × 0.4 mm sheets, and the dielectric constant and dielectric loss tangent of the sample at a frequency of 10 GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0155] Example 11

[0156] Add 150 mL of methanol, 0.09 mol of N,N-di-tert-butylethylenediamine, and 0.07 mol of copper bromide to a 2 L four-necked flask. After stirring and dissolving, continuously bubble with oxygen while maintaining the temperature at 40-45 °C. Add a 500 mL toluene / 150 mL methanol mixture of 1.0 mol of 2,6-dimethylphenol and 0.125 mol of tetramethylbisphenol A to the reaction flask. After the addition is complete, continue bubbling with oxygen and stirring at the same temperature for 4 h. After the reaction is complete, neutralize with 10% dilute hydrochloric acid. Add 50 mL of an aqueous solution containing 7 g (0.04 mol) of EDTA-2Na and stir for 30 min. Add 600 mL of methanol, filter out the precipitate, and wash three times with 300 mL of methanol. Dry under vacuum at 80 °C for 8 h to obtain 285.0 g of polyphenylene ether (XSPPO); Mn = 1750, Mw = 2030.

[0157] Add 120 mL of toluene, 60 g of polyphenylene ether (SXPPO), 60 mL of 50% sodium hydroxide solution, 4 g (0.043 mol) of tetrabutylammonium bromide, 0.1 g of 701 polymerization inhibitor, and 15 g (0.18 mol) of p-chloromethylstyrene to a 500 mL four-necked flask. Stir and heat to 70 °C under nitrogen protection; stir for 8 h; cool to room temperature and neutralize with 10% dilute hydrochloric acid; wash the organic phase three times with 200 mL of water; add to 800 mL of methanol, filter the precipitate, wash with methanol / water (weight ratio 80:20), and dry under vacuum at 80 °C for 8 h to obtain 82 g of modified polyphenylene ether (XSmPPO), Mn = 1860, Mw = 2180; the structural formula of XSmPPO is:

[0158]

[0159] 4 g (0.01 mol) of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), 16 g of XSmPPO, and 0.1 g of T311 peroxide initiator prepared in Example 1 were dissolved in 50 g of toluene. The solvent was removed under reduced pressure, and then crosslinked resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70-80 mmHg, time 100 min). The glass transition temperature was determined. The crosslinked resin was made into 80 mm × 80 mm × 0.4 mm sheets, and the dielectric constant and dielectric loss tangent of the sample at a frequency of 10 GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0160] Example 12

[0161] 9,9-bis(4-vinylbenzyl)-9H-fluorene (p,p-BVBF) was prepared according to the method of Example 9;

[0162] Modified polyphenylene ether (XSmPPO) was prepared according to the method of Example 11;

[0163] 4 g (0.01 mol) p,p-BVBF, 16 g XSmPPO, and 0.1 g T311 peroxide initiator were dissolved in 50 g toluene. The solvent was removed under reduced pressure, and then crosslinked resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70-80 mmHg, time 100 min). The glass transition temperature was determined. The crosslinked resin was made into 80 mm × 80 mm × 0.4 mm sheets, and the dielectric constant and dielectric loss tangent of the sample at a frequency of 10 GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0164] Example 13

[0165] 9,9-bis(4-vinylbenzyl)-9H-fluorene (p,p-BVBF) was prepared according to the method of Example 9;

[0166] Modified polyphenylene ether (XSmPPO) was prepared according to the method of Example 11;

[0167] 2 g (0.005 mol) of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF), 2 g (0.005 mol) of p,p-BVBF, 16 g of XSmPPO, and 0.1 g of T311 peroxide initiator prepared in Example 1 were dissolved in 50 g of toluene. The solvent was removed under reduced pressure, and then crosslinked resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70-80 mmHg, time 100 min). The glass transition temperature was determined. The crosslinked resin was made into 80 mm × 80 mm × 0.4 mm sheets, and the dielectric constant and dielectric loss tangent of the sample at a frequency of 10 GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0168] Comparative Example 1

[0169] 20 g of 1,2-bis(4-vinylphenyl)ethane (BVPE) and 0.1 g of T311 peroxide initiator were dissolved in 50 g of toluene. The solvent was removed under reduced pressure, and then a thermosetting hydrocarbon resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70~80mmHg, time 100min). The glass transition temperature was determined. The resin was made into 80mm×80mm×0.4mm resin sheets, and the dielectric constant and dielectric loss tangent of the samples at a frequency of 10GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0170] Comparative Example 2

[0171] Modified polyphenylene ether (XSmPPO) was prepared according to the method of Example 11;

[0172] 20g of modified polyphenylene ether (XSmPPO) and 0.1g of T311 peroxide initiator were dissolved in 50g of toluene, and the solvent was removed under reduced pressure. Then, a thermosetting resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70~80mmHg, time 100min). The glass transition temperature was determined. The resin was made into 80mm×80mm×0.4mm sheets, and the dielectric constant and dielectric loss tangent of the sample at a frequency of 10GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0173] Comparative Example 3

[0174] Modified polyphenylene ether (XSmPPO) was prepared according to the method of Example 11;

[0175] 2.34 g (0.01 mol) of 1,2-bis(4-vinylphenyl)ethane (BVPE), 17.66 g of modified polyphenylene ether (XSmPPO), and 0.1 g of T311 peroxide initiator were dissolved in 50 g of toluene, and the solvent was removed under reduced pressure. Then, a crosslinked resin was prepared by melt casting (thermosetting conditions: temperature 220℃, pressure 70-80 mmHg, time 100 min). The glass transition temperature was determined. The crosslinked resin was made into 80 mm × 80 mm × 0.4 mm sheets, and the dielectric constant and dielectric loss tangent of the sample at a frequency of 10 GHz were determined using an Agilent N5230A vector network analyzer. The results are listed in Table 4.

[0176] Table 4. Performance parameters of the thermosetting resins prepared in Examples 8-13 and Comparative Examples 1-3.

[0177]

[0178]

[0179] In Table 4, Dk is the dielectric constant, Df is the dielectric loss tangent, and Tg is the glass transition temperature.

[0180] Table 4 shows that the thermosetting hydrocarbon resins prepared from 9,9-bis(4-vinylbenzyl)-9H-fluorene exhibit very low dielectric loss tangents and relatively high glass transition temperatures (Examples 8, 9, and 10). Among them, the thermosetting hydrocarbon resin prepared from 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) has the lowest dielectric loss tangent and the highest glass transition temperature (Example 8). The crosslinked resins of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene (o,p-BVBF) (Example 11), 9,9-bis(4-vinylbenzyl)-9H-fluorene (p,p-BVBF) (Example 12), or a 1:1 mixture of both (Example 13) with terminal vinyl-modified polyphenylene ether exhibit significantly lower dielectric constants, substantially lower dielectric loss tangents, and significantly higher glass transition temperatures compared to crosslinked resins of 1,2-bis(4-vinylphenyl)ethane (BVPE) with terminal vinyl-modified polyphenylene ether (Comparative Example 3). Furthermore, the higher the weight percentage of o,p-BVBF used as the crosslinking agent, the lower the dielectric loss tangent and the higher the glass transition temperature. Therefore, the thermosetting hydrocarbon resin and the thermosetting crosslinked resin with modified polyphenylene ether of the present invention possess excellent comprehensive properties and can be used as resin materials for high-frequency, high-speed printed circuit boards.

[0181] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A thermosetting resin, characterized in that, Thermosetting hydrocarbon resin prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene as a raw material; The 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene is an asymmetric divinylbenzylfluorene with the structure shown in Formula 1: Formula 1; The thermal analysis of 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene shows a melting endothermic peak at 169~175℃, indicating a monoclinic crystal system with space group P21 / c. The thermosetting hydrocarbon resin prepared using 9-(2-vinylbenzyl)-9'-(4-vinylbenzyl)-9H-fluorene as the raw material has a glass transition temperature of 360°C, and a dielectric constant and dielectric loss tangent of 2.8 and 0.00030 at a frequency of 10 GHz, respectively. The method for preparing the thermosetting resin includes the following steps: The raw materials and initiator were dissolved in toluene to obtain a mixed solution; After removing toluene from the mixed solution, the solution is subjected to melt thermosetting to obtain the thermosetting resin.

2. The thermosetting resin according to claim 1, characterized in that, The method for preparing the asymmetric divinylbenzylfluorene according to claim 1 includes the following steps: Fluorene, a basic reagent, a polymerization inhibitor, and a polar aprotic solvent are mixed to obtain a fluorene-containing mixed system. The asymmetric divinylbenzylfluorene is obtained by sequentially adding 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, or by adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, to the fluorene-containing mixed system to carry out a nucleophilic substitution reaction.

3. The thermosetting resin according to claim 2, characterized in that, The alkaline reagent includes one or more of alkali metal hydroxides, alkali metal alkoxides, sodium hydride, and potassium hydride; The polymerization inhibitor includes one or more of nitromethane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide, and 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide. The polar aprotic solvents include dimethyl sulfoxide, sulfolane, N,N-dimethylformamide, N,N-diethylformamide, acetonitrile, or hexamethylphosphoramide; The molar ratio of fluorene to alkaline reagent is 1:1.8~5; The molar ratio of 2-vinylbenzyl chloride to 4-vinylbenzyl chloride is 2~6:4~8; The total molar amount of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride and the molar ratio of fluorene are 1.8~2.2:

1.

4. The thermosetting resin according to claim 2 or 3, characterized in that, The nucleophilic substitution reaction is carried out at a temperature of 20-50°C for 2-8 hours.

5. The thermosetting resin according to claim 1, characterized in that, The preparation method of the asymmetric divinylbenzylfluorene includes the following steps: Fluorene, a basic reagent, a polymerization inhibitor, a phase transfer catalyst, and a solvent were mixed to obtain a fluorene-containing phase transfer catalytic system. The asymmetric divinylbenzylfluorene is obtained by sequentially adding 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, or by adding a mixed solution of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride, to the fluorene-containing phase transfer catalytic system under phase transfer catalytic conditions for nucleophilic substitution reaction.

6. The thermosetting resin according to claim 5, characterized in that, The alkaline reagent includes alkali metal hydroxides and / or alkali metal alkoxides; The polymerization inhibitor includes one or more of nitromethane, nitrobenzene, o-nitrophenol, phenothiazine, 2-phenylnaphthylamine, hydroquinone, catechol, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, p-tert-butyl-catechol, 2,2,6,6-tetramethylpiperidine nitroxide, and 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide. The phase transfer catalyst includes one or more of quaternary ammonium salts, quaternary phosphorus salts, and polyethylene glycol; The mass of the phase transfer catalyst is 5-25% of the mass of fluorene; The molar ratio of fluorene to alkaline reagent is 1:1.8~5; The molar ratio of 2-vinylbenzyl chloride to 4-vinylbenzyl chloride is 2~6:4~8; The total molar amount of 2-vinylbenzyl chloride and 4-vinylbenzyl chloride and the molar ratio of fluorene are 1.8~2.2:

1.

7. The thermosetting resin according to claim 5 or 6, characterized in that, The nucleophilic substitution reaction under the phase transfer catalytic conditions is carried out at a temperature of 25-75°C for 8-18 hours.

8. A method for preparing the thermosetting resin according to any one of claims 1 to 7, characterized in that, Includes the following steps: The raw materials and initiator were dissolved in toluene to obtain a mixed solution; After removing toluene from the mixed solution, the solution is subjected to melt thermosetting to obtain the thermosetting resin.

9. The application of the thermosetting resin according to any one of claims 1 to 7 or the thermosetting resin prepared by the preparation method according to claim 8 as a resin material for high-frequency and high-speed substrates.

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