Low dielectric active ester, preparation method and application thereof, and resin composition

Abstract

The invention provides low-dielectric-activity ester, a preparation method and application thereof and a resin composition, and relates to the technical field of epoxy resin curing agents, the low-dielectric-activity ester is a polymer containing a styrene-acrylic cyclobutene structure, and the polymer is prepared through an esterification reaction of phenolic resin and styrene-acrylic cyclobutene acyl chloride. The synthesis steps are simple, and the active ester curing agent with low dielectric property, low thermal expansion coefficient and high heat resistance can be synthesized by a one-step method.

Description

Technical Field

[0001] This invention relates to the field of epoxy resin curing agent technology, and in particular to a low dielectric active ester, its preparation method and application, and resin composition. Background Technology

[0002] Modern electronic products demand high-speed and high-volume information transmission, driving the development of digital signal technology towards higher frequencies. To achieve this, substrate materials must possess low dielectric constants and low dielectric loss tangents to reduce damping effects on electrical signals, thereby increasing transmission speed and minimizing signal loss. Furthermore, electronic devices are trending towards high integration, density, and multifunctionality. As chip integration increases, so does power consumption. Increased power consumption generates more heat, and sustained high temperatures can gradually degrade the performance and reliability of electronic products. This is manifested in reduced connection reliability due to the mismatch in thermal expansion between the substrate material and the chip, posing a serious challenge to the overall reliability and stability of the product.

[0003] In substrate materials, resin compositions formed by combining epoxy resin with curing agents such as amines, phenolic resins, and cyanate esters can generate polar groups that hinder further improvement in the resin's dielectric properties. In contrast, thermosetting resin systems composed of reactive esters and epoxy resins do not generate additional hydroxyl groups (-OH) during the reaction, exhibiting low dielectric loss and low water absorption, thus meeting the electrical performance requirements of next-generation substrate materials.

[0004] The substrate material must match the coefficient of thermal expansion (CTE1 (25-150℃)) to ≤20 ppm / ℃ to prevent cracking during a single reflow soldering cycle. CTE2 (150-245℃) must be extremely low (≤100 ppm / ℃) to avoid delamination failure after multiple reflow soldering cycles. TGA measurements show a 5wt% loss temperature >350℃ (meeting high-temperature lead-free soldering and long-term reliability requirements), with higher values ​​being preferable. Currently, improving the CTE2 (150-245℃) of materials still relies on traditional filler additions, but this leads to poor subsequent processability, and the filler-resin interface easily becomes a crack initiation point, severely impacting the long-term reliability of the substrate.

[0005] For example, Chinese invention patent application CN 119306606 A discloses a hyperbranched active ester curing agent containing double bonds and its composition. Although the Df can be as low as 0.0050, its CTE1 (25-150℃) is as high as 51ppm / ℃, and the CTE2 (150-245℃) is not given. It is evident that there is currently a lack of effective strategies and methods to improve CTE2.

[0006] Therefore, how to provide a resin material that combines low dielectric loss characteristics and ultra-low thermal expansion rate has become an urgent problem to be solved in this field.

[0007] In view of this, the present invention is proposed. Summary of the Invention

[0008] One of the objectives of this invention is to provide a low dielectric activity ester to at least solve one of the technical problems existing in the prior art.

[0009] The second objective of this invention is to provide a method for preparing a low dielectric active ester.

[0010] A third objective of this invention is to provide an application of the low-dielectric-activity ester prepared by the aforementioned method in the preparation of resin compositions.

[0011] The fourth objective of this invention is to provide a resin composition.

[0012] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a low dielectric active ester, wherein the low dielectric active ester is a polymer containing a phenylcyclobutene structure, and the polymer is prepared by esterification reaction of phenolic resin and phenylcyclobutenoyl chloride.

[0013] Furthermore, the phenolic resin includes one or more of the following: phenolic resin, DCPD phenolic resin, phenolic aromatic hydrocarbon resin, and phenolic biphenyl resin.

[0014] Secondly, the present invention provides a method for preparing a low-dielectric-activity ester, comprising: esterifying a phenolic resin with phenylcyclobutenoyl chloride in the presence of a catalyst and a base to obtain the low-dielectric-activity ester.

[0015] Furthermore, the molar ratio of the phenolic resin to phenylcyclobutenoyl chloride is 1:1.3-1.6; the molar ratio of the phenolic resin to the catalyst is 1:0.08-0.12; and the molar ratio of the phenolic resin to the alkali is 1:1.5-1.7. Preferably, the catalyst comprises one or more of 4-dimethylaminopyridine, 1,8-diazabicycloundec-7-ene, and potassium carbonate; Preferably, the base comprises one or more of triethylamine, pyridine, and DIPEA; Preferably, the organic solvent used in the esterification reaction includes one or more of toluene, dichloromethane, and chloroform.

[0016] Furthermore, the esterification reaction is carried out at a temperature of 85-95°C for 4-6 hours.

[0017] Furthermore, the phenylcyclobutenoyl chloride is prepared by reacting phenylcyclobutenoic acid with a chlorinating agent; Preferably, the phenylcyclobutenoic acid comprises bicyclic [4.2.0]octyl-1,3,5-triene-3-carboxylic acid; The chlorinating agent includes one or more of thionyl chloride, oxalyl chloride, phosphorus pentachloride, and phosphorus oxychloride; The organic solvent used in the reaction of phenylcyclobutenoic acid with the chlorinating agent includes one or more of dichloromethane, chloroform, or tetrahydrofuran; The reaction of phenylcyclobutenoic acid with the chlorinating agent is carried out in the presence of a catalytic amount of an organic nitrogen compound; Preferably, the organic nitrogen compound includes N,N-dimethylformamide; Preferably, the molar ratio of phenylcyclobutenoic acid to the chlorinating agent is 1:1.2 to 1.4; Preferably, the reaction temperature of the phenylcyclobutenoic acid with the chlorinating agent is 40-45°C, and the reaction time is 1-3 hours.

[0018] Furthermore, after the esterification reaction, a post-treatment is also included, which includes: removing the solvent and volatile components by rotary evaporation, washing with dichloromethane and water, separating the organic phase, and then purifying by silica gel column chromatography to obtain the low dielectric activity ester.

[0019] Thirdly, the present invention provides the application of a low dielectric active ester prepared by the aforementioned preparation method in the preparation of resin compositions.

[0020] Fourthly, the present invention provides a resin composition comprising the following components: epoxy resin, reactive ester curing agent, filler, curing accelerator, additives, and solvent; The active ester curing agent includes a low-dielectric active ester prepared by the preparation method described above.

[0021] Furthermore, the resin composition comprises, by weight, the following components: 11-14 parts epoxy resin, 12-13 parts reactive ester curing agent, 70-80 parts filler, 0.1-0.5 parts curing accelerator, and 40-60 parts solvent; Preferably, the resin composition further includes 1-2 parts of additives; the additives include one or more of leveling agents, defoamers, thickeners, and homogenizers; Preferably, the epoxy resin comprises a low dielectric epoxy resin; Preferably, the filler comprises one or more of spherical silica, fused silica powder, surface-modified silica micropowder, and hollow glass microspheres; Preferably, the solvent includes one or both of butanone and cyclohexanone.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The low-dielectric-activity ester provided by this invention introduces a styrene-cyclobutene structure into the phenolic resin backbone to form a polymer with a highly rigid aromatic ring structure. During the curing process, it can generate dibenzocyclooctadiene (DBCOD) units with near-zero thermal expansion characteristics, thereby significantly reducing the coefficient of thermal expansion (CTE2) of the material at high temperatures. At the same time, this active ester does not produce strongly polar groups such as hydroxyl groups when reacting with epoxy resin, effectively reducing the dielectric constant and dielectric loss of the resin system. It has both excellent electrical properties and thermal dimensional stability, making it suitable for high-frequency and high-speed electronic packaging. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 The TMA test diagram for application example 2; Figure 2 The TMA test diagram for application example 3; Figure 3 The TMA test diagram for application example 4; Figure 4 The TMA test diagram for application example 5; Figure 5 The TMA test diagram is for application example 7; Figure 6 To compare the TMA test chart in Application Example 1; Figure 7 For comparison, see the TMA test chart in Application Example 2. Detailed Implementation

[0025] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The first aspect of the present invention provides a low dielectric active ester, wherein the low dielectric active ester is a polymer containing a phenylcyclobutene structure, and the polymer is prepared by esterification reaction of phenolic resin and phenylcyclobutenoyl chloride.

[0028] The low-dielectric active ester provided by this invention is a low-dielectric-loss, low-thermal-expansion-coefficient active ester. Styrene-cyclobutene resin has extremely low dielectric constant and loss, and after curing, it exhibits high crosslinking density and a high-rigidity aromatic ring backbone. Furthermore, one of the generated products, the dibenzocyclooctadiene (DBCOD) unit, has a near-zero thermal expansion coefficient due to the unique conformational transformation of the DBCOD unit. Therefore, this invention aims to utilize styrene-cyclobutene combined with an active ester to synthesize a series of active ester curing agents possessing both low dielectric loss characteristics and ultra-low thermal expansion coefficients. Using these as curing agents, combined with epoxy resins, fillers, etc., resin compositions with low dielectric loss, low CTE, and high heat resistance are obtained, ensuring the performance of the substrate material in the field of integrated circuit packaging.

[0029] This invention utilizes different series of phenolic resins to react with phenylcyclobutene chloride or acids to prepare a series of phenylcyclobutene-containing active esters, such as phenolic resins, DCPD phenols, phenolic aromatic hydrocarbons, and phenolic biphenyls reacting with phenylcyclobutene chloride. The reaction formula is as follows:

[0030] In some preferred embodiments, the phenolic resin includes one or more of phenolic resins, DCPD phenolic resins, phenolic aromatic hydrocarbon phenolic resins, and phenolic biphenyl phenolic resins.

[0031] A second aspect of the present invention provides a method for preparing a low-dielectric-activity ester, comprising: esterifying a phenolic resin with phenylpropylcyclobutenoyl chloride in the presence of a catalyst and a base to obtain the low-dielectric-activity ester.

[0032] The present invention features a simple synthesis process, enabling the one-step synthesis of an active ester curing agent with low dielectric constant, low coefficient of thermal expansion, and high heat resistance. Using this as a curing agent, combined with epoxy resin, fillers, etc., a resin composition with low dielectric loss, low CTE, and high heat resistance can be obtained. While exhibiting low dielectric loss (Df 0.0047@10GHz), it also possesses a low CTE1 (25-150℃) of 14.6ppm / ℃, and particularly an extremely low CTE2 (150-245℃) of 22ppm / ℃, with a Td (5%wt) 10℃ higher than the comparative.

[0033] In some preferred embodiments, the molar ratio of the phenolic resin to phenylcyclobutenoyl chloride (equivalent to the formulation ratio eq.) is 1:1.3 to 1.6, preferably 1.5; the molar ratio of the phenolic resin to the catalyst (equivalent to the formulation ratio eq.) is 1:0.08 to 0.12, preferably 0.1; and the molar ratio of the phenolic resin to the base (equivalent to the formulation ratio eq.) is 1:1.5 to 1.7, preferably 1.6. Preferably, the catalyst comprises one or more of 4-dimethylaminopyridine (DMAP), 1,8-diazabicycloundec-7-ene (DBU), and potassium carbonate; Preferably, the base comprises one or more of triethylamine, pyridine, and DIPEA; Preferably, the organic solvent used in the esterification reaction includes one or more of toluene, dichloromethane, and chloroform.

[0034] In some preferred embodiments, the temperature of the esterification reaction is 85-95°C, for example, 85°C, 90°C, 95°C, etc.; the reaction time is 4-6 hours, for example, 4 hours, 5 hours, 6 hours, etc.

[0035] In some preferred embodiments, the phenylcyclobutenoyl chloride is prepared by reacting phenylcyclobutenoic acid with a chlorinating agent; Preferably, the phenylcyclobutenoic acid comprises bicyclic [4.2.0]octyl-1,3,5-triene-3-carboxylic acid; The chlorinating agent includes one or more of thionyl chloride, oxalyl chloride, phosphorus pentachloride, and phosphorus oxychloride; The organic solvent used in the reaction of phenylcyclobutenoic acid with the chlorinating agent includes one or more of dichloromethane, chloroform, or tetrahydrofuran; The reaction of phenylcyclobutenoic acid with the chlorinating agent is carried out in the presence of a catalytic amount of an organic nitrogen compound; Preferably, the organic nitrogen compound includes N,N-dimethylformamide; Preferably, the molar ratio (equivalent to the mixing ratio eq.) of the phenylcyclobutenoic acid to the chlorinating reagent is 1:1.2 to 1.4, and more preferably 1.3; Preferably, the reaction temperature of the phenylcyclobutenoic acid with the chlorinating agent is 40-45℃, for example, 40℃, 41℃, 42℃, 43℃, 44℃, 45℃, etc., and the reaction time is 1-3 hours, for example, 1 hour, 2 hours, 3 hours, etc.

[0036] In some preferred embodiments, the esterification reaction is followed by a post-treatment process, which includes: rotary evaporation to remove solvent and volatile components, washing with dichloromethane and water, separating the organic phase, and then purifying by silica gel column chromatography to obtain the low-dielectric-activity ester.

[0037] A third aspect of this invention provides the application of the low-dielectric-activity ester prepared by the aforementioned method in the preparation of resin compositions. This invention utilizes the synthesized active ester as a curing agent to prepare a series of compositions, which are then coated into films and their physical properties, such as Tg, CTE, and electrical properties, are tested.

[0038] A fourth aspect of the present invention provides a resin composition comprising the following components: epoxy resin, an active ester curing agent, a filler, a curing accelerator, and a solvent; wherein the active ester curing agent comprises a low-dielectric active ester prepared by the preparation method described above.

[0039] This invention utilizes phenylcyclobutene chloride to synthesize a series of low-dielectric polymeric active esters containing phenylcyclobutene structures with a series of phenolic resins. The synthesis is a one-pot process, with simple steps and readily available raw materials. By substituting a simple formula with epoxy resin, the synthesized active ester, filler, catalyst, film-forming resin, and leveling agent, a thickening film can be coated. After curing, the resin composition exhibits low dielectric constant, low coefficient of thermal expansion, and excellent heat resistance.

[0040] In some preferred embodiments, the resin composition comprises, by weight, the following components: 11-14 parts epoxy resin, 12-13 parts reactive ester curing agent, 70-80 parts filler, 0.1-0.5 parts curing accelerator, and 40-60 parts solvent; In the resin composition, the amount of epoxy resin added is 11-14 parts, for example, 11 parts, 12 parts, 13 parts, 14 parts, etc. In the resin composition, the amount of active ester curing agent added is 12-13 parts, for example, 12 parts, 12.5 parts, 13 parts, etc. In the resin composition, the amount of filler added is 70-80 parts, for example, 70 parts, 75 parts, 80 parts, etc.; In the resin composition, the amount of curing accelerator added is 0.1-0.5 parts, for example, it can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.; In the resin composition, the amount of solvent added is 40-60 parts, for example, 40 parts, 50 parts, 60 parts, etc.

[0041] Preferably, the resin composition further includes 1-2 parts of an additive, such as 1 part, 1.5 parts, 2 parts, etc.; the additive includes one or more of leveling agents, defoamers, thickeners, and homogenizers. Preferably, the epoxy resin comprises a low dielectric epoxy resin; Preferably, the filler comprises one or more of spherical silica (such as SCO2), fused silica powder, surface-modified silica micropowder, and hollow glass microspheres; Preferably, the solvent includes one or both of butanone and cyclohexanone.

[0042] Alternatively, a low coefficient of thermal expansion can be achieved by adding fiberglass cloth (the CTE of fiberglass is extremely low (typical value: 5-6 ppm / ℃). This invention can also be used in the field of copper clad laminates, where it can be made into a prepreg and then used to prepare a prepreg, which can further reduce the CTE while the fiberglass cloth reduces the CTE.

[0043] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0044] Example 1 This embodiment provides a low dielectric activity ester, the synthesis steps of which are as follows: Step 1: Reaction equation:

[0045] Table 1 below shows the material input: Table 1

[0046] Experimental steps: Experimental steps: 1. Under natural conditions, add benzocyclobutene carboxylic acid and dichloromethane to a 500 mL three-necked flask and stir until completely dissolved.

[0047] 2. Under natural conditions, add 2-3 drops of DMF to a 500 mL three-necked flask using a syringe.

[0048] 3. Under natural conditions, while stirring, slowly add thionyl chloride to a 50 mL three-necked flask using a syringe.

[0049] 4. Heat to 40~45℃, and after 2 hours, monitor with TLC. Once the reaction is complete, evaporate directly to dryness for later use. Step 2: Synthesis of low dielectric active esters: Taking biphenyl aryl phenolic aldehyde as an example (Example 1: Synthesis of low dielectric active esters). The reaction equation is as follows:

[0050] Table 2 below shows the material input: Table 2

[0051] Experimental steps: 1. Under natural conditions, add phenolic resin, DMAP, triethylamine and toluene to a 250 mL three-necked flask and stir until completely dissolved.

[0052] 2. Under natural conditions, slowly add 30 mL of the dissolved product from the previous step to a 250 mL three-necked flask using a constant-pressure dropping funnel. (Observe the reaction state; if the reaction is exothermic, an ice bath is required); the dropping rate can be controlled to be completed within 1 hour. 3. Heat to 90℃ and react for 5 hours, monitoring with TLC to ensure complete reaction of the phenolic resin; 4. After the reaction is complete, remove triethylamine and toluene by rotary evaporation, add dichloromethane and a large amount of water, and wash several times. 5. Purification: After passing through a short silica gel column, 6.73 g of the corresponding low-dielectric-activity ester was obtained, with a yield of 94.90%. Example 2 This embodiment provides a low-dielectric-active ester, which differs from Example 1 in that: the phenolic resin is SH7110, and 3.77g of it is added to obtain 5.72g of low-dielectric-active ester, with a yield of 89.2%; the structure of SH7110 is as follows: , where n = 0.5~10.

[0053] Example 3 This embodiment provides a low-dielectric-active ester, which differs from Example 1 in that: the phenolic resin is SH4100, and 3.48g is added to obtain 4.25g of low-dielectric-active ester, with a yield of 69.4%; The SH4100 structure is as follows: , where n = 2 - 6.

[0054] Example 4 This embodiment provides a low-dielectric-active ester, which differs from Example 1 in that: the phenolic resin is SH8011, and 3.24g of it is added to obtain 5.73g of low-dielectric-active ester, with a yield of 70.3%; The structure of SH8011 is as follows: , where n = 5 - 20.

[0055] Comparative Example 1 This comparative example provides a conventional active ester, HPC-8000-65T.

[0056] Application Example 1 This application example provides a resin composition comprising: epoxy resin, reactive ester curing agent, filler, curing accelerator, leveling agent, and solvent, wherein the reactive ester curing agent is the low dielectric reactive ester prepared in Example 1; the specific component selection and weight parts are shown in Table 3; The resin composition is prepared as follows: After the raw material components of the insulating laminate film are mixed evenly in proportion, they are coated onto a PET release film. After drying at 90°C for 3 minutes, the PET release film is removed to obtain the insulating laminate film.

[0057] Application Example 2 This application example provides a resin composition that differs from Application Example 1 in that the component ratios are different, as detailed in Table 3.

[0058] Application Example 3 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is the low dielectric active ester prepared in Example 2, and the component ratio is different, as shown in Table 3.

[0059] Application Example 4 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is the low dielectric active ester prepared in Example 2, and the component ratio is different, as shown in Table 3.

[0060] Application Example 5 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is the low dielectric active ester prepared in Example 3, and the component ratio is different, as shown in Table 3.

[0061] Application Example 6 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is the low dielectric active ester prepared in Example 3, and the component ratio is different, as shown in Table 3.

[0062] Application Example 7 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is the low dielectric active ester prepared in Example 4, and the component ratios are different, as shown in Table 3.

[0063] Application Example 8 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is the low dielectric active ester prepared in Example 4, and the component ratios are different, as shown in Table 3.

[0064] Comparative Application Example 1 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is a low dielectric active ester provided in Comparative Example 1, and the specific component ratios are shown in Table 3.

[0065] Comparative Application Example 2 This application example provides a resin composition that differs from Application Example 1 in that the active ester curing agent is a low dielectric active ester provided in Comparative Example 1, and the specific component ratios are shown in Table 3.

[0066] Table 3

[0067] The thermodynamic and dielectric properties of the thickened films obtained from the above application examples and comparative application examples were tested. The specific test methods are as follows: Thermal expansion coefficient and glass transition temperature: The obtained laminated film was cured at 220℃ for 120 min, and then the substrate was peeled off to obtain the test sample; the test sample was cut into test pieces with a width of 5 mm and a length of 10 mm, and tested in tensile mode using a thermomechanical analysis device with a preload force of 0.05 N. First scan: room temperature to 150℃ (heating rate 10℃ / min), and after the temperature dropped to room temperature, the thermal stress was removed; Second scan: room temperature to 260℃ (heating rate 3℃ / min), and after the temperature dropped to room temperature, the data of the second cooling segment were taken to obtain CTE1 (25-150℃) and CTE2 (150-245℃), and TMA Tg; Dielectric constant: The obtained laminated film was cured at 220℃ for 120 min, and then the substrate was peeled off to obtain the test sample; the test sample was cut into 80mm×100mm test pieces, and then the product was baked in an oven at 105℃ / 2H, and tested under the conditions of 23±1~5℃ and 50±5% relative humidity. Then, the dielectric constant and dielectric loss of the test piece were determined by SPDR method at a measurement frequency of 10GHz. Thermal decomposition temperature (Td) test: The obtained laminated film was cured at 220℃ for 120 min, and then the substrate was peeled off to obtain the test sample; the test was carried out in accordance with the provisions of 9.10 in GB / T 33016—2016.

[0068] The test results are shown in Table 4.

[0069] Table 4

[0070] As shown in Table 4, the present invention, through the design of specific proportions of styrene-containing cyclobutene resin, low-dielectric epoxy resin, and fillers, as well as the mutual compounding of each component, forms a highly cross-linked system with low polarity and high rigidity in the cured product, enabling the resin composition to achieve characteristics such as low coefficient of thermal expansion, high glass transition temperature, and low dielectric loss. Application Examples 1 to 8 used styrene-containing reactive esters derived from phenolic resins with different structures as curing agents. The CTE1 (25-150℃) and CTE2 (150-245℃) of their cured films were significantly better than those of the system using the conventional reactive ester HPC-8000-65T in the comparative application examples (CTE1 21~23.9ppm / ℃, CTE2 79~81ppm / ℃), and the Tg was significantly better than the comparative example, indicating that it has superior thermal dimensional stability. Furthermore, in Application Examples 1 to 6, the Dk (10 GHz) of the cured film ranged from 3.13 to 3.30, and the Df (10 GHz) ranged from 0.0048 to 0.0058, which is almost equivalent to the system using the conventional active ester HPC-8000-65T in the comparative application examples (Df 0.0044 and 0.0047, respectively). These data indicate that the examples achieved better thermal dimensional stability while maintaining low dielectric loss. Application Example 2 was particularly outstanding, specifically, in Application Example 2, CTE1 (25-150 °C) was as low as 14.0 ppm / °C, CTE2 (150-245 °C) was as low as 22.1 ppm / °C, Tg (TMA) was as high as 177.7 °C, and Df (10 GHz) ≤ 0.0048. This indicates that by introducing a highly rigid phenylcyclobutene structure and forming a dibenzocyclooctadiene (DBCOD) crosslinking network, the system effectively suppresses molecular chain segment movement at high temperatures, thereby significantly reducing thermal expansion behavior.

[0071] Comparing Table 4, it can be seen that compared to Application Examples 1 and 2, which do not contain the phenylcyclobutene structure, their CTE1 (25-150℃), CTE2 (150-245℃), and Tg show varying degrees of degradation, especially CTE2, which reaches as high as 79-81 ppm / ℃. From Figures 1-7 It can be seen that using phenolic resin-derived active esters containing phenylcyclobutene with different structures as curing agents, the CTE1 (25-150℃) and CTE2 (150-245℃) of the cured film are significantly better than those of the system using the traditional active ester HPC-8000-65T in the comparative application example (CTE1 21~23.9ppm / ℃, CTE2 79~81ppm / ℃), and the Tg is significantly better than that of the comparative example, indicating that it has better thermal dimensional stability.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low dielectric active ester characterized in that, The low dielectric active ester is a polymer containing a phenylpropylcyclobutene structure, which is prepared by esterification of phenolic resin and phenylpropylcyclobutene acid chloride.

2. The low dielectric active ester according to claim 1, characterized in that, The phenolic resin comprises one or more of phenol novolac phenolic resin, DCPD phenol phenolic resin, phenol aralkane phenolic resin and phenol biphenyl phenolic resin.

3. The method for preparing a low dielectric active ester according to claim 1 or 2, characterized by, Comprise: The phenolic resin and the phenylpropylcyclobutene acid chloride are subjected to esterification in the presence of a catalyst and a base to obtain the low dielectric active ester.

4. The production method according to claim 3, characterized by, The molar ratio of the phenolic resin to the phenylpropylcyclobutene acid chloride is 1:1.3-1.6; the molar ratio of the phenolic resin to the catalyst is 1:0.08-0.12; and the molar ratio of the phenolic resin to the base is 1:1.5-1.

7. Preferably, the catalyst comprises one or more of 4-dimethylamino pyridine, 1,8-diazabicycloundec-7-ene and potassium carbonate; Preferably, the base comprises one or more of triethylamine, pyridine and DIPEA; Preferably, the organic solvent used in the esterification reaction comprises one or more of toluene, dichloromethane and chloroform.

5. The preparation method according to claim 3, characterized in that, The temperature of the esterification reaction is 85-95℃, and the reaction time is 4-6 hours.

6. The preparation method according to claim 3, characterized in that, The phenylpropylcyclobutene acid chloride is prepared by reacting phenylpropylcyclobutene acid with a chlorinating agent; Preferably, the phenylpropylcyclobutene acid comprises bicyclo[4.2.0]octa-1,3,5-triene-3-carboxylic acid; The chlorinating agent comprises one or more of dichlorosulfoxide, oxalyl chloride, phosphorus pentachloride and phosphorus oxychloride; The organic solvent used in the reaction of the phenylpropylcyclobutene acid with the chlorinating agent comprises one or more of dichloromethane, chloroform or tetrahydrofuran; The reaction of the phenylpropylcyclobutene acid with the chlorinating agent is carried out in the presence of a catalytic amount of an organic nitrogen compound; Preferably, the organic nitrogen compound comprises N,N-dimethylformamide; Preferably, the molar ratio of the phenylpropylcyclobutene acid to the chlorinating agent is 1:1.2-1.4; Preferably, the temperature of the reaction of the phenylpropylcyclobutene acid with the chlorinating agent is 40-45℃, and the reaction time is 1-3 hours.

7. The preparation method according to claim 3, characterized in that, After the esterification reaction, a post-treatment is further included, which comprises: removing the solvent and volatile components by rotary evaporation, adding dichloromethane and water for washing, separating the organic phase, and then purifying by silica gel column chromatography to obtain the low dielectric active ester.

8. Use of the low dielectric active ester prepared by the preparation method of any one of claims 3-7 in the preparation of a resin composition.

9. A resin composition characterized by comprising: Comprise the following components: epoxy resin, active ester curing agent, filler, curing accelerator, auxiliary agent and solvent; The active ester curing agent comprises the low dielectric active ester prepared by the preparation method of any one of claims 3-7.

10. The resin composition according to claim 9, characterized by The resin composition comprises the following components in parts by weight: 11-14 parts of epoxy resin, 12-13 parts of active ester curing agent, 70-80 parts of filler, 0.1-0.5 parts of curing accelerator and 40-60 parts of solvent; Preferably, the resin composition further comprises 1-5 parts of auxiliary agent; the auxiliary agent comprises one or more of leveling agent, defoaming agent, thickening agent and homogenizing agent; Preferably, the epoxy resin comprises a low dielectric epoxy resin; Preferably, the filler comprises one or more of spherical silica, fused quartz powder, surface-modified silica micropowder, and hollow glass microspheres. Preferably, the solvent comprises one or more of butanone and cyclohexanone, toluene.

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