Vinyl aromatic acid ester active ester compound as well as preparation method and application thereof
By combining vinyl aromatic ester active ester compounds with epoxy resin, the problems of high dielectric loss and high coefficient of thermal expansion of epoxy resin materials are solved, and a new type of epoxy resin material with low dielectric loss, low coefficient of thermal expansion and high glass transition temperature is prepared, which is suitable for high-frequency communication and military electronic equipment.
Patent Information
- Application Number
- CN202511252368.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-03
- Publication Date
- 2025-10-28
AI Technical Summary
Existing epoxy resin materials suffer from high dielectric loss and high coefficient of thermal expansion in high-frequency communication and military electronic equipment, leading to signal attenuation, localized high temperature and mechanical reliability issues. The high CTE and low Tg of traditional reactive ester curing agents limit their application.
A novel epoxy resin material with low dielectric loss, low coefficient of thermal expansion, and high glass transition temperature was prepared by compounding vinyl aromatic ester active ester compounds with epoxy resin and catalyzing the esterification reaction with carbodiimide compounds and organic bases.
It achieves material properties of low dielectric loss, low coefficient of expansion and high glass transition temperature in the high frequency band, reduces processing risks and costs, and is suitable for industrial production.
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Figure CN120842084A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of low dielectric resin materials, specifically to a vinyl aromatic ester active ester compound, its preparation method, and its application. Background Technology
[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
[0003] With the rapid development of 5G high-frequency communication and military electronic technology, the requirements for signal transmission performance in mobile terminals, servers, and base stations have significantly increased. The signal spectrum is extending towards the millimeter-wave band, and transmission rates are evolving towards the terahertz level, posing a severe challenge to the electromagnetic wave transmission efficiency and accuracy of materials. However, existing epoxy resin materials face a dual bottleneck: on the one hand, high dielectric loss (Df>0.01) not only leads to signal attenuation and delay but also causes localized high temperatures due to energy dissipation, accelerating material aging and even functional failure. On the other hand, a high coefficient of thermal expansion (CTE>80ppm / ℃) induces interfacial shear stress during thermal cycling, which, under long-term action, can easily cause mechanical reliability problems such as solder joint cracking and circuit breakage. To address these challenges, there is an urgent need to develop novel epoxy resin materials with high frequency, low transmission loss, and low coefficient of thermal expansion to meet market demands. In contrast, while materials such as polytetrafluoroethylene (PTFE) and cyanate ester resins exhibit significant advantages in dielectric properties and heat resistance, their complex synthesis processes and high manufacturing costs limit their large-scale application. Epoxy resins, with their designable molecular chains, offer material systems that combine process adaptability and performance tunability, attracting considerable attention in the field of high-frequency, low-dielectric materials. Therefore, developing novel high-performance epoxy resin materials with low dielectric constant (Df) and low catalytic conductivity (CTE) has become a key research focus in fields such as chip packaging, printed circuit boards, and radomes.
[0004] For epoxy resin materials, simultaneously achieving high frequency (8.2~10GHz), low dielectric loss (Df<0.005), low coefficient of thermal expansion (CTE<50ppm), and high glass transition temperature (Tg>180℃) remains a challenge. While traditional reactive ester curing agents and epoxy resins produce epoxy composites with relatively excellent dielectric properties, the high CTE and low Tg significantly limit their application in fields such as electronic packaging. This study designed a novel reactive ester curing agent and, through curing with epoxy resin, successfully designed a novel epoxy resin composite material with high frequency, low Df, low CTE, and high Tg. Due to the reasonable raw material prices and convenient synthesis method, industrial production is expected to be feasible. Summary of the Invention
[0005] To prepare epoxy resin materials with low dielectric loss (Df<0.005), low coefficient of thermal expansion (CTE<50ppm), and high glass transition temperature (Tg>180℃), this invention provides a vinyl aromatic ester reactive ester compound, its preparation method, and its application in epoxy resin composites. This invention addresses the problems of high CTE and low Tg in traditional reactive esters while ensuring low Df, achieving low Df, low CTE, and high Tg simultaneously, thus further meeting the application requirements of the material.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] The vinyl aromatic ester active ester compound prepared by the present invention is represented by the following general formula (1);
[0008] General formula (1)
[0009] In the general formula (1), AR is the structure represented by general formula (2), general formula (3), general formula (4), general formula (5), general formula (6) or general formula (7); R1 to R3 may be the same or different, representing hydrogen or methyl;
[0010] The hydroxyl groups linked by the connecting bonds in the structures of general formulas (2), (3), (4), (5), (6), or (7) can be located at any position on the aromatic ring. R in general formula (2) represents hydrogen or methyl.
[0011] In the general formula (5), D represents -CH2-, -C(CH3)2-, -CH(CH3)-, sulfone, ether bond or -C(CF3)2-.
[0012] General formula (2);
[0013] General formula (3);
[0014] General formula (4);
[0015] General formula (5);
[0016] General formula (6);
[0017] General formula (7);
[0018] The method for synthesizing the vinyl aromatic ester active ester compounds of the present invention is not limited, and the following synthesis methods can be used to effectively manufacture the vinyl aromatic ester active ester compounds.
[0019] Using carbodiimide compounds as decarboxylating agents and organic bases as catalysts, vinyl aromatic acid compounds are esterified with monocyclic or polycyclic aromatic phenolic compounds to obtain vinyl aromatic acid ester active ester compounds.
[0020] The carbodiimide compounds include one or more combinations of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N,N-dicyclohexylcarbodiimide, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. Since esterification reactions catalyzed by concentrated acids or bases typically require high temperatures to achieve high yields, significantly complicating the reaction process, using carbodiimide compounds as decarboxylating agents can effectively promote a milder reaction and ensure a high yield. The core function of the organic base catalyst is to significantly improve reaction efficiency and selectivity by enhancing nucleophilicity and accelerating intermediate conversion.
[0021] The organic base includes one or more combinations of tertiary amine compounds, imidazole compounds, and phosphine compounds. The tertiary amine compounds include one or more combinations of triethylamine, benzyldimethylamine, and 4-dimethylaminopyridine; the imidazole compounds include one or more combinations of 4-dimethylimidazole, 2-methylimidazole, and 2-phenylimidazole; and the phosphine compounds include one or more combinations of triphenylphosphine and tributylphosphine.
[0022] The method for manufacturing the aromatic phenolic compound is not limited, and the aromatic phenolic compound is represented by the following structural formulas (1), (2), (3), (4), (5) or (6);
[0023] Structural formula (1), where R represents hydrogen or methyl.
[0024] Structural formula (2)
[0025] Structural formula (3)
[0026] Structural formula (4), where D represents -CH2-, -C(CH3)2-, -CH(CH3)-, sulfone, ether bond or -C(CF3)2-.
[0027] Structural formula (5)
[0028] Structural formula (6).
[0029] Vinyl aromatic acid compounds only require the presence of vinyl and carboxyl groups on the aromatic ring; the positional relationship between the vinyl and carboxyl groups is not limited.
[0030] The input amounts or reaction conditions of aromatic phenolic compounds and vinyl aromatic acid compounds are determined based on the reactivity of the two compounds, and are set according to the suitable activation ratio of the carbodiimide compound. The mass ratio of aromatic phenolic compounds to vinyl aromatic acid compounds is 0.1-2. The preferred mass ratio of carbodiimide compounds to vinyl aromatic acids is 0.5-2. The preferred mass ratio of organic base catalyst to vinyl aromatic acid is 0.1-1.
[0031] Solvents used in the reaction of aromatic phenolic compounds with vinyl aromatic acids include acetone, butanone, toluene, dichloromethane, or tetrahydrofuran.
[0032] The application of the aforementioned vinyl aromatic ester active ester compound involves compounding and curing the vinyl aromatic ester active ester compound with epoxy resin under the catalysis of an organic base to obtain an active ester / epoxy resin composite material.
[0033] The epoxy resins mentioned are all derived from common epoxy resins, including bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, and other epoxy resins with binary or higher epoxy groups. These epoxy resins can be used alone or in combination to achieve specific performance requirements.
[0034] From the perspectives of dielectric properties and thermal stability, biphenyl-type epoxy resin, naphthalene-type epoxy resin, and dicyclopentadiene-type epoxy resin are preferred.
[0035] The ratio of the vinyl aromatic ester active ester compound (general formula 1) to the epoxy resin is preferably selected to be in the range of 0.2 to 2 by mass.
[0036] The organic base catalyst primarily functions as a curing accelerator, promoting the curing of the ester groups in vinyl aromatic ester active ester compounds with epoxy resin. Known substances can be used, including one or more combinations of tertiary amine compounds, imidazole compounds, and phosphine compounds. Specifically: the tertiary amine compounds include one or more combinations of triethylamine, benzyldimethylamine, and 4-dimethylaminopyridine; the imidazole compounds include one or more combinations of 4-dimethylimidazole, 2-methylimidazole, and 2-phenylimidazole; and the phosphine compounds include one or more combinations of triphenylphosphine and tributylphosphine. These organic base catalysts can be used alone or in combination to achieve specific performance characteristics. The organic base added during the preparation of the active ester / epoxy resin composite material accounts for 0.5%-5% of the total mass of the raw materials.
[0037] The raw materials for composite curing also include inorganic fillers. The inorganic filler is silica, including one or a combination of two types of amorphous silica with a particle size of 0.1-3 μm and amorphous silica with a particle size of 5 μm. To maintain a high inorganic filler dosage, the two fillers are mixed at a mass ratio of (5%-70%) and (95%-30%).
[0038] The proportion of the inorganic filler can be adjusted according to different applications, and the amount of inorganic filler added usually accounts for 5% to 80% of the total mass of the raw materials.
[0039] Compared with the prior art, the present invention has the following beneficial effects:
[0040] 1. The preparation of vinyl aromatic ester active ester curing agents is carried out under mild conditions and avoids the strong acid or strong base catalysts used in traditional esterification processes, which greatly reduces the preparation risks in the synthesis process.
[0041] 2. The vinyl aromatic ester active ester curing agent prepared by this invention has a simple synthesis process, high and stable yield, and readily available raw materials, making it suitable for industrial production.
[0042] 3. Vinyl aromatic ester active ester curing agents not only have excellent compatibility with epoxy resins, but also have low viscosity at high temperatures, which greatly improves the processing technology.
[0043] 4. A novel composite material was prepared by combining vinyl aromatic esters with epoxy resin and silica. This composite material exhibits excellent dielectric and thermal properties: in the high-frequency band of 8.2-10 GHz, the dielectric constant is less than 3; the dielectric loss is stable in the range of 0.003-0.004; the CTE value is reduced to 34.22 ppm / ℃; and the Tg is greater than 180℃.
[0044] 5. The present invention has the advantages of simple preparation method, convenient curing process, strong practicality and low preparation cost. Attached Figure Description
[0045] Figure 1 This is a test graph of the dielectric constant of the active ester / epoxy resin composite material prepared in Example 7;
[0046] Figure 2 This is a test graph of the dielectric loss of the active ester / epoxy resin composite material prepared in Example 7. Detailed Implementation
[0047] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0048] In the following embodiments, the following test methods are used:
[0049] Dielectric performance testing was performed at room temperature using a vector network analyzer and waveguide testing methods.
[0050] Example 1
[0051] In a nitrogen atmosphere, 33 parts of vinyl aromatic acid, 12 parts of resorcinol, 42 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 13 parts of 4-dimethylaminopyridine (DMAP) were dissolved in dichloromethane at room temperature and reacted for 24 hours. After the reaction, the mixture was washed in ethanol and then recrystallized in dichloromethane to obtain the final product Rev3. 52 parts of Rev3, 47 parts of bisphenol A epoxy resin, 1 part of DMAP, and 0 parts of silica were added to a tetrafluoroethylene mold and placed in an oven at 120°C. The temperature was increased by 30°C every 2 hours until the curing temperature reached 210°C, yielding the active ester / epoxy resin composite material FRev3.
[0052] Example 2
[0053] In a nitrogen atmosphere, 33 parts of vinyl aromatic acid, 17 parts of 1,6-naphthol, 40 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 10 parts of DMAP were dissolved in dichloromethane at room temperature and reacted for 24 hours. After the reaction, the mixture was washed in ethanol and then recrystallized in dichloromethane to obtain the final product BCP. 55 parts of BCP, 44 parts of bisphenol A epoxy resin, 1 part of DMAP, and 0 parts of silica were added to a tetrafluoroethylene mold and placed in an oven at 120°C. The temperature was increased by 30°C every 2 hours until the curing temperature reached 210°C, yielding the reactive ester / epoxy resin composite material FBCP.
[0054] Example 3
[0055] In a nitrogen atmosphere, 31 parts of vinyl aromatic acid, 21 parts of biphenyl hydrochloride, 39 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 9 parts of DMAP were dissolved in dichloromethane at room temperature and reacted for 24 hours. After the reaction, the mixture was washed in ethanol and then recrystallized in dichloromethane to obtain the final product CCP. 57 parts of CCP, 42 parts of bisphenol A epoxy resin, 1 part of DMAP, and 0 parts of silica were added to a tetrafluoroethylene mold and placed in an oven at 120°C. The temperature was increased by 30°C every 2 hours until the curing temperature reached 210°C, yielding the reactive ester / epoxy resin composite material FCCP.
[0056] Example 4
[0057] In a nitrogen atmosphere, 29 parts of vinyl aromatic acid, 23 parts of 2,2-bis(p-hydroxyphenyl)propane, 38 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 10 parts of DMAP were dissolved in dichloromethane at room temperature and reacted for 24 hours. After the reaction, the solution was washed in ethanol and then recrystallized in dichloromethane to obtain the final product DCP. 51 parts of DCP, 48 parts of bisphenol A epoxy resin, 1 part of DMAP, and 0 parts of silica were added to a tetrafluoroethylene mold and placed in an oven at 120°C. The temperature was increased by 30°C every 2 hours until the curing temperature reached 210°C, yielding the reactive ester / epoxy resin composite material FDCP.
[0058] Example 5
[0059] In a nitrogen atmosphere, 33 parts of vinyl aromatic acid, 12 parts of resorcinol, 42 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 13 parts of DMAP were dissolved in dichloromethane at room temperature and reacted for 24 hours. After the reaction, the mixture was washed in ethanol and then recrystallized in dichloromethane to obtain the final product Rev3.
[0060] 47 parts Rev3, 43 parts bisphenol A epoxy resin, 1 part DMAP and 9 parts silica were added to a tetrafluoroethylene mold and placed in an oven at 120°C. The temperature was increased by 30°C every 2 hours until the curing temperature reached 210°C, thus obtaining the active ester / epoxy resin composite material FRev3 / 9%SiO2.
[0061] Example 6
[0062] In a nitrogen atmosphere, 33 parts of vinyl aromatic acid, 12 parts of resorcinol, 42 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 13 parts of DMAP were dissolved in dichloromethane at room temperature and reacted for 24 hours. After the reaction, the mixture was washed in ethanol and then recrystallized in dichloromethane to obtain the final product Rev3. 40 parts of Rev3, 36 parts of bisphenol A epoxy resin, 0.7 parts of DMAP, and 23.3 parts of silica were added to a tetrafluoroethylene mold and placed in an oven at 120°C. The temperature was increased by 30°C every 2 hours until the curing temperature reached 210°C, yielding the active ester / epoxy resin composite material FRev3 / 23.3%SiO2.
[0063] Example 7
[0064] In a nitrogen atmosphere, 33 parts of vinyl aromatic acid, 12 parts of resorcinol, 42 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 13 parts of DMAP were dissolved in dichloromethane at room temperature and reacted for 24 hours. After the reaction, the mixture was washed in ethanol and then recrystallized in dichloromethane to obtain the final product Rev3. 35 parts of Rev3, 32 parts of bisphenol A epoxy resin, 0.6 parts of DMAP, and 32.4 parts of silica were added to a tetrafluoroethylene mold and placed in an oven at 120°C. The temperature was increased by 30°C every 2 hours until the curing temperature reached 210°C, yielding the active ester / epoxy resin composite material FRev3 / 32.4%SiO2. The dielectric constant and dielectric loss graphs are shown below. Figure 1 and 2 As shown.
[0065] Comparative Example 1
[0066] 65 parts of bisphenol A epoxy resin and 35 parts of 4,4-diaminodiphenylmethane were mixed evenly and added into a tetrafluoroethylene mold. The mold was placed in an oven at 120°C and the temperature was increased by 20°C every 2 hours until the curing temperature reached 160°C to obtain the resin material FSAA.
[0067] Comparative Example 2
[0068] 51 parts of bisphenol A epoxy resin, 48 parts of methyl hexahydrophthalic anhydride and 1 part of N,N-dimethylbenzylamine were mixed evenly and added to a tetrafluoroethylene mold. The mold was placed in an oven at 120°C and the temperature was increased by 20°C every 2 hours until the curing temperature reached 160°C to obtain the resin material FSSG.
[0069] Detailed data is shown in Table 1.
[0070]
[0071] The active ester / epoxy resin composite material prepared by this invention has low Df and low CTE, while also possessing excellent comprehensive performance. Moreover, the required raw materials are reasonably priced, making it promising for industrial production.
[0072] This invention introduces vinyl groups into the molecular structure, significantly reducing the processing viscosity of the cured system, greatly reducing the dielectric loss of the cured product, and simultaneously increasing the crosslinking density of the cured product, thereby improving the dielectric properties, mechanical properties, and thermal stability of epoxy resin materials. Compared with existing technologies, this curing agent has the following advantages: (1) the resulting cured product has low dielectric loss and excellent overall performance; (2) a wide curing process window and convenient operation; (3) a simple synthesis process, readily available raw materials, and low production cost. This curing agent can be widely used in electronic packaging, radar transmission windows, composite materials, coatings, and other fields.
[0073] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A vinyl aromatic ester active ester compound, characterized in that: The structural formula of the compound is shown in general formula (1): General formula (1); AR is the structure represented by the following general formulas (2), (3), (4), (5), (6) or (7); R1 to R3 may be the same or different, representing hydrogen or methyl; General formula (2), where R represents hydrogen or methyl; General formula (3); General formula (4); General formula (5), where D represents -CH2-, -C(CH3)2-, -CH(CH3)-, sulfone, ether bond or -C(CF3)2-; General formula (6); General formula (7).
2. A method for preparing the vinyl aromatic ester active ester compound according to claim 1, characterized in that, Includes the following steps: Using carbodiimide compounds as decarboxylating agents and organic bases as catalysts, aromatic phenolic compounds are esterified with vinyl aromatic acids to obtain vinyl aromatic ester active ester compounds.
3. The preparation method according to claim 2, characterized in that: The mass ratio of aromatic phenolic compounds to vinyl aromatic acid compounds is 0.1-2:1, the mass ratio of carbodiimide compounds to vinyl aromatic acids is 0.5-2:1, and the mass ratio of organic bases to vinyl aromatic acids is 0.1-1:
1.
4. The preparation method according to claim 2, characterized in that: The carbodiimide compounds include any one or more combinations of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N,N-dicyclohexylcarbodiimide, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride; the organic bases include one or more combinations of tertiary amine compounds, imidazole compounds, and phosphine compounds.
5. The preparation method according to claim 4, characterized in that: The tertiary amine compounds include one or more combinations of triethylamine, benzyldimethylamine, and 4-dimethylaminopyridine; the imidazole compounds include one or more combinations of 4-dimethylimidazole, 2-methylimidazole, and 2-phenylimidazole; and the phosphine compounds include one or a combination of triphenylphosphine and tributylphosphine.
6. The preparation method according to claim 2, characterized in that: The aromatic phenolic compounds are represented by the following structural formulas (1), (2), (3), (4), (5), or (6); Structural formula (1), wherein R is hydrogen or methyl; Structural formula (2); Structural formula (3); Structural formula (4), wherein D is -CH2-, -C(CH3)2-, -CH(CH3)-, sulfone, ether bond or -C(CF3)2-; Structural formula (5); Structural formula (6).
7. The application of the vinyl aromatic ester active ester compound according to claim 1, characterized in that: Reactive ester / epoxy resin composites are obtained by compounding and curing vinyl aromatic ester active ester compounds with epoxy resin under organic base catalysis.
8. The application according to claim 7, characterized in that: The mass ratio of vinyl aromatic ester active ester compound to epoxy resin is 0.2-2:1, and the organic base accounts for 0.5%-5% of the total mass of the raw materials.
9. The application according to claim 7, characterized in that: The raw materials for composite curing include inorganic fillers, and the inorganic fillers account for 5% to 80% of the total mass of the raw materials.
10. The application according to claim 9, characterized in that: The inorganic filler is silicon dioxide, which includes one or a combination of two types of amorphous silicon dioxide with a particle size of 0.1-3 μm and amorphous silicon dioxide with a particle size of 5 μm.