Low-dielectric low-water-absorption epoxy resin, resin composition and method for producing the same

Abstract

The application is suitable for preparation of high molecular compound, and provides a preparation method of low dielectric and low water absorption rate epoxy resin, wherein TBBA, fluorine-containing hydroxyl compound, bisphenol type diglycidyl ether and tetraphenyl ethane phenolic resin are added into a reactor, and stirred and heated to 80-110 DEG C, and kept at the temperature for 1.5-3.5 h, then heated to 120-150 DEG C, and a catalyst is added, and kept at the temperature for reaction, and then heated to 160-190 DEG C for 4-7 h, bisphenol type diglycidyl ether and phenolic epoxy resin are added, and kept at 120-140 DEG C, and cooled to 100-120 DEG C, and solvent is added dropwise, and the low dielectric and low water absorption rate epoxy resin is prepared after mixing, dissolving and being transparent; the preparation process is simple, the prepared low dielectric and low water absorption rate epoxy resin product has good performance, has excellent low dielectric performance, low water absorption rate, excellent flame retardance and heat resistance stability, has the characteristics of environment friendliness, simple operation, fast reaction speed and low cost, and has strong practicability.

Description

Technical Field

[0001] This invention pertains to the preparation of polymer compounds, specifically a low-dielectric-rate, low-water-absorption epoxy resin, a resin composition, and a method for its preparation. The low-dielectric-rate, low-water-absorption epoxy resin prepared by this invention is particularly suitable as a matrix resin for Low Dk electronic copper-clad laminates and has broad application prospects in fields such as high-performance printed circuit boards. Background Technology

[0002] With the rapid development of cloud computing, the Internet of Things and big data, the high frequency, high speed and small size of electronic products have placed higher demands on printed circuit boards, which are the carriers of information transmission and the polymer resins that are important components of them. The polymer resins are required to have low dielectric constant and dielectric loss.

[0003] Currently, low-dielectric-constant copper-clad laminates (CCLs) are generally manufactured using high-performance resins such as polytetrafluoroethylene (PTFE), cyanate ester resins, polyphenylene ether (PPE) resins, or polyimide resins, combined with low-dielectric-constant, low-dielectric-loss fiberglass cloth. These CCLs all possess excellent dielectric properties, but each also has its own drawbacks. PTFE resin has a high melt viscosity, requiring PTFE-based CCLs to be pressed at high temperatures of 380–400°C, resulting in a complex process. PPE resin-based CCLs require toluene in their manufacturing process, causing environmental pollution, and also suffer from high melt viscosity. Cyanate ester-based CCLs are too expensive. Polyimide resin-based CCLs are also expensive and have complex manufacturing processes.

[0004] Besides using high-performance resin materials, the overall performance of a composition can be further improved by selecting epoxy resins and curing agents with specific structures and through their interactions. CN201310206428A discloses a thermosetting resin composition for integrated circuits, which contains allyl-modified bismaleimide prepolymer, anhydride compounds, benzoxazine resin, epoxy resin, flame retardant, curing agent, accelerator, and inorganic filler. After curing, this resin composition exhibits excellent heat resistance and flame retardancy, while also possessing the low dielectric constant of anhydrides, meeting the production process requirements of high-density interconnect (HDI) and other high-performance printed circuit boards. CN201410230519A discloses a halogen-free resin composition, in which the curing action of phosphorus-containing active esters gives the product good heat resistance, low dielectric constant, and low moisture absorption, solving the problem of decreased dielectric and moisture absorption properties caused by halogen-free flame retardancy in the prior art.

[0005] Epoxy resin, as a traditional matrix resin, has excellent physical and mechanical properties, bonding properties, wear resistance, high chemical stability, high temperature resistance, electrical insulation properties, as well as advantages such as low shrinkage, easy processing and molding, and low cost. However, the saturated water absorption rate of epoxy resin is generally 1% to 2%, and the dielectric constant under 10G conditions is generally 3.0 to 3.4, which cannot meet the requirements for high-performance copper-clad laminates. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a low-dielectric-content, low-water-absorption epoxy resin and its composition. This invention redesigns the product structure by introducing a fluorinated compound into the epoxy resin backbone. Utilizing the low polarizability of the C-F bond, the resin is endowed with low dielectric properties and low moisture absorption. Furthermore, by compounding with a low-hydroxyl epoxy resin, an epoxy resin and its composition with excellent low dielectric and low water absorption are prepared.

[0007] This invention is implemented as follows: a low-dielectric-density, low-water-absorption epoxy resin, wherein the structural formula of the low-dielectric-density, low-water-absorption epoxy resin is: or or or

[0008] The molecular weight of the low dielectric and low water absorption epoxy resin is 1000-5000. In the formula: m = 1~5, R is C(CF3)2, CH2, C(CH3)2, And n=1~10, and z=1~5, R1 and R3 are H or CH3 or F, R2 and R4 are H or CH3 or F, and R5 and R6 are... .

[0009] As a further aspect of the present invention, the method for preparing a low-dielectric-weight, low-water-absorption epoxy resin includes the following steps: S1. Add 1-5 parts by weight of TBBA, 15-25 parts by weight of fluorinated hydroxyl compound, 35-55 parts by weight of bisphenol diglycidyl ether, and 1-3 parts by weight of tetraphenol ethane phenolic resin to the reactor, and heat to 80℃-110℃ with stirring, and maintain the temperature for 1.5-3.5h. S2, then heat to 120℃~150℃ and add 0.2~1 part by mass of catalyst, and keep the temperature for 30 min; S3. Then heat to 160℃~190℃ and react for 4~7h. Then add 25~60 parts by weight of bisphenol diglycidyl ether and 5~9 parts by weight of phenolic epoxy resin, and keep the temperature at 120℃~140℃ for 30min. S4. Then cool to 100℃~120℃, add 25~40 parts by weight of solvent, and wait for it to mix and dissolve until it becomes transparent to obtain low dielectric and low water absorption epoxy resin.

[0010] As a further embodiment of the present invention, the fluorinated hydroxy compound is one or a mixture of several of bisphenol AF, tetrafluoroterephthalic acid, and tetrafluorohydroquinone.

[0011] As a further embodiment of the present invention, the bisphenol diglycidyl ether is one or a mixture of two of E51 epoxy resin, E54 epoxy resin, N-170 epoxy, E12, and E20.

[0012] As a further embodiment of the present invention, the catalyst is one or a mixture of two of imidazole, triphenylphosphine, triphenyl phosphate, triethylbenzylammonium chloride, tetrabutylammonium bromide, and butyltriphenylphosphine bromide.

[0013] As a further aspect of the present invention, the phenolic epoxy resin is one or a mixture of two of the following: phenolic epoxy resin, bisphenol A phenolic epoxy resin, o-cresol phenolic epoxy resin, and DCPD phenolic epoxy resin.

[0014] As a further aspect of the present invention, the solvent is one of butanone, acetone, a mixture of butanone and propylene glycol methyl ether, or a mixture of acetone and propylene glycol methyl ether.

[0015] As a further embodiment of the present invention, the low-dielectric-low-water-absorption epoxy resin composition is prepared using the low-dielectric-low-water-absorption epoxy resin as raw material. The resin composition is mainly composed of low-dielectric-low-water-absorption epoxy resin, low-hydroxyl epoxy resin, thixotropic agent, filler, phenolic epoxy resin, active ester curing agent, and methyl ethyl ketone (MEK), with the following weight proportions: 10-40 parts low-dielectric-low-water-absorption epoxy resin, 10-20 parts low-hydroxyl epoxy resin, 0-5 parts thixotropic agent, 0-140 parts filler, 1-5 parts phenolic epoxy resin, 40-50 parts active ester curing agent, and 60-85 parts MEK.

[0016] As a further aspect of the present invention, the low-hydroxyl epoxy resin is end-capped with MDI to produce a low-hydroxyl epoxy resin with a mass percentage content of 70±1% and a hydroxyl equivalent of 5000 to 10000.

[0017] As a further embodiment of the present invention, the thixotropic agent is one or a mixture of several of fumed silica and surface-treated fumed silica; the filler is molten spherical silica powder, and the average particle size D95 of the filler is ≤15 micrometers; the active ester curing agent is one or a combination of several of DFE616, DFE617, DFE617L or DFE618 from Dongcai Technology Group Co., Ltd.

[0018] Compared with the prior art, the beneficial effects of the present invention are: (1) In this invention, fluorine-containing hydroxyl compounds are used as nucleophiles. Through nucleophilic substitution reaction, fluorine is introduced into the molecular backbone. The low polarizability of C-F bond is used to give the resin low dielectric properties and low moisture absorption. At the same time, bromine is introduced into the reaction to obtain low dielectric and low water absorption epoxy resin with flame retardant function, which greatly improves the possibility of epoxy resin being used for high-performance copper-clad laminates. (2) By compounding with low-hydroxyl epoxy, the present invention prepares a resin composition with good comprehensive performance. The copper clad laminate prepared by it has a small dielectric constant, low water absorption, good hygrothermal stability and heat resistance, which meets the application requirements of high-performance copper clad laminate. (3) The preparation process of this invention is simple, and the low dielectric and low water absorption epoxy resin (solution) product obtained has good performance. It has excellent low dielectric properties, low water absorption, excellent flame retardancy and heat resistance stability. It is environmentally friendly, easy to operate, fast reaction speed and low cost, and has strong practicality. Attached Figure Description

[0019] Figure 1 Table of raw material ratios and process parameters for preparing low dielectric and low water absorption epoxy resins in Examples 1-1 to 1-9 of this invention; Figure 2 The following is a material ratio table for the low dielectric and low water absorption epoxy resin compositions in Examples 2-1 to 2-9 of this invention; Figure 3 The table shows the performance results of copper-clad laminates with low dielectric and low water absorption epoxy resin compositions in Examples 2-1 to 2-9 of this invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0022] A low-dielectric, low-water-absorption epoxy resin, wherein the structural formula of the low-dielectric, low-water-absorption epoxy resin is as follows: or or or

[0023] The low dielectric and low water absorption epoxy resin has a molecular weight of 1000-5000. The physicochemical data of the prepared low dielectric and low water absorption epoxy resin solution are as follows: solid content 79%-81%, viscosity 1000-2000 mPa·s, epoxy equivalent 380-430 g / eq, fluorine content 9%-13%, glass transition temperature 135℃-145℃, and it is a reddish-brown transparent liquid. In the formula: m = 1~5, R is C(CF3)2, CH2, C(CH3)2, And n=1~10, and z=1~5, R1 and R3 are H or CH3 or F, R2 and R4 are H or CH3 or F, and R5 and R6 are... ; The definition of "solid quantity" in this invention is: the percentage of the mass of non-volatile matter in 1g of sample (i.e., low dielectric and low water absorption epoxy resin solution) after baking in an oven at 160°C for 1 hour, and the final solid quantity is determined by calculating the mass of solvent added based on the mass of non-volatile matter. The definition of "fluorine content" in this invention is: the percentage of fluorine content in the total mass of low dielectric and low water absorption epoxy resin solids.

[0024] Example 1-1: A method for preparing a low-dielectric-content, low-water-absorption epoxy resin includes the following steps: 42 parts by weight of bisphenol A type diglycidyl ether E51, 2 parts by weight of TBBA, 24 parts by weight of bisphenol AF, and 1 part by weight of tetraphenol ethane phenolic resin are added to a reactor. The mixture is heated to 80°C (T1, same in subsequent examples) under stirring, and the reaction is maintained at this temperature for 1.5 hours (t1, same in subsequent examples). Then, the temperature is raised to 120°C, 0.2 parts by weight of triphenylphosphine catalyst are added, and the reaction is maintained at this temperature for 30 minutes. Finally, the temperature is raised to 170°C. The reaction was carried out at ℃ (T2, same in subsequent examples) for 4 hours (t2, same in subsequent examples). Then, 5 parts by mass of bisphenol F diglycidyl ether 170 epoxy resin, 9 parts by mass of phenolic epoxy resin 638s, and 20 parts by mass of bisphenol diglycidyl ether E20 were added. The reaction was maintained at 120℃ (T3, same in subsequent examples) for 30 minutes (t3, same in subsequent examples). Then, the mixture was cooled to 100℃, and 26 parts by mass of solvent were added dropwise. After mixing and dissolving until transparent, a low dielectric and low water absorption epoxy resin was obtained. The product has a fluorine content of 13.0% and an epoxy equivalent of 404 g / eq.

[0025] Examples 1-2: A method for preparing a low-dielectric, low-water-absorption epoxy resin includes the following steps: 35 parts by mass of bisphenol A type diglycidyl ether E51, 1 part by mass of TBBA, 22 parts by mass of bisphenol AF, and 2 parts by mass of tetraphenol ethane phenolic resin are added to a reactor. The mixture is heated to 80°C with stirring and maintained at this temperature for 1.5 hours. Then, the temperature is raised to 125°C, and 0.2 parts by mass of butyltriphenylphosphine bromide catalyst are added. The mixture is kept at this temperature for 30 minutes, and then the temperature is raised to 170°C (and kept at this temperature) for 4 hours. Next, 9 parts by mass and 23 parts by mass of bisphenol A type diglycidyl ether E54 and E51, and 5 parts by mass of phenolic epoxy resin 638s are added respectively. The mixture is kept at 120°C for 30 minutes. The mixture is then cooled to 110°C, and 24 parts by mass of solvent are added dropwise. After mixing and dissolving until transparent, the low-dielectric, low-water-absorption epoxy resin is obtained. The product has a fluorine content of 12.0% and an epoxy equivalent of 412 g / eq.

[0026] Examples 1-3: A method for preparing a low-dielectric-rate, low-water-absorption epoxy resin includes the following steps: 55 parts by mass of bisphenol A type diglycidyl ether E51, 3 parts by mass of TBBA, 4 parts by mass of bisphenol AF, 18 parts by mass of tetrafluorohydroquinone, and 1 part by mass of tetraphenol ethane phenolic resin are added to a reactor. The mixture is heated to 90°C under stirring and maintained at this temperature for 2 hours. Then, the temperature is raised to 125°C and 0.8 parts by mass of tetrabutylammonium bromide catalyst are added. The mixture is kept at this temperature for 30 minutes. The temperature is then raised to 180°C and kept at this temperature for 5 hours. Next, 6 parts by mass of phenolic epoxy resin 638s, 9 parts by mass of bisphenol type diglycidyl ether E20, 11 parts by mass of E51, and 9 parts by mass of bisphenol F type diglycidyl ether 170 epoxy are added. The mixture is kept at 120°C and kept at this temperature for 30 minutes. Then, the mixture is cooled to 110°C and 32 parts by mass of solvent are added dropwise. After mixing and dissolving until transparent, the low-dielectric-rate, low-water-absorption epoxy resin is obtained. The product has a fluorine content of 12.5% ​​and an epoxy equivalent of 409 g / eq.

[0027] Examples 1-4: A method for preparing a low-dielectric-rate, low-water-absorption epoxy resin includes the following steps: 35 parts by mass of bisphenol diglycidyl ether E51, 1 part by mass of TBBA, 1 part by mass of bisphenol AF, 22 parts by mass of tetrafluoroterephthalic acid, and 1 part by mass of tetraphenol ethane phenolic resin are added to a reactor. The mixture is heated to 90°C under stirring and maintained at this temperature for 2 hours. Then, the temperature is raised to 140°C and 0.3 parts by mass of imidazole catalyst are added. The mixture is kept at this temperature for 30 minutes. The temperature is then raised to 160°C and kept at this temperature for 5 hours. Next, 7 parts by mass of bisphenol A phenolic epoxy resin BNE200, 15 parts by mass of bisphenol diglycidyl ether E12, 6 parts by mass of E54, and 26 parts by mass of bisphenol F diglycidyl ether 170 epoxy resin are added. The mixture is kept at 130°C and kept at this temperature for 30 minutes. Then, the temperature is cooled to 110°C and 29 parts by mass of butanone are added dropwise. After mixing and dissolving until transparent, the low-dielectric-rate, low-water-absorption epoxy resin is obtained. The product has a fluorine content of 10.5% and an epoxy equivalent of 429 g / eq.

[0028] Examples 1-5: A method for preparing a low-dielectric, low-water-absorption epoxy resin includes the following steps: 2 parts by mass of TBBA, 35 parts by mass of bisphenol diglycidyl ether E51, 2 parts by mass of tetraphenol ethane phenolic resin, 4 parts by mass of tetrafluorohydroquinone, and 15 parts by mass of tetrafluoroterephthalic acid are added to a reactor. The mixture is heated to 100°C with stirring and maintained at this temperature for 3 hours. Then, the temperature is raised to 145°C, 0.3 parts by mass of triphenylphosphine catalyst are added, and the reaction is maintained at this temperature for 30 minutes. The temperature was raised to 160℃ and the reaction was maintained for 6 hours. Then, 5 parts by weight of bisphenol A phenolic epoxy resin BNE200, 25 parts by weight of bisphenol type diglycidyl ether E12, 15 parts by weight of E54, and 7 parts by weight of bisphenol F type diglycidyl ether 170 epoxy were added. The reaction was maintained at 130℃ for 30 minutes, and then cooled to 110℃. 3 parts by weight of propylene glycol methyl ether and 25 parts by weight of acetone were added dropwise. After mixing and dissolving until transparent, a low dielectric and low water absorption epoxy resin was obtained. The product has a fluorine content of 9.5% and an epoxy equivalent of 422 g / eq.

[0029] Examples 1-6: A method for preparing a low-dielectric-content, low-water-absorption epoxy resin includes the following steps: adding 3 parts by mass of TBBA, 38 parts by mass of bisphenol diglycidyl ether E51, 1 part by mass of tetraphenol ethane phenolic resin, 1 part by mass of bisphenol AF, 2 parts by mass of tetrafluorohydroquinone, and 18 parts by mass of tetrafluoroterephthalic acid to a reactor; heating the mixture to 100°C with stirring; maintaining this temperature for 3 hours; then heating the mixture to 135°C and adding 0.4 parts by mass of triphenyl phosphate catalyst; and maintaining the temperature for 3 hours. After 0 min, the temperature was raised to 180℃ (and held) for 6 h. Then, 7 parts by weight of o-cresol formaldehyde epoxy resin CNE704, 28 parts by weight of bisphenol type diglycidyl ether E12, 15 parts by weight of E54, and 8 parts by weight of bisphenol F type diglycidyl ether 170 epoxy were added. The reaction was maintained at 130℃ for 30 min, then cooled to 110℃. 1 part by weight of propylene glycol methyl ether and 29 parts by weight of butanone were added dropwise. After mixing and dissolving until transparent, a low dielectric and low water absorption epoxy resin was obtained. The product has a bromine content of 9.3% and an epoxy equivalent of 398 g / eq.

[0030] Examples 1-7: A method for preparing a low-dielectric-rate, low-water-absorption epoxy resin includes the following steps: 5 parts by mass of TBBA, 54 parts by mass of bisphenol-type diglycidyl ether E51, 3 parts by mass of tetraphenol ethane phenolic resin, 23 parts by mass of tetrafluorohydroquinone, and 2 parts by mass of tetrafluoroterephthalic acid diethanolamide are added to a reactor. The mixture is heated to 110°C under stirring and maintained at this temperature for 3.5 hours. Then, the temperature is raised to 130°C and 0.4 parts by mass of triphenyl phosphate catalyst are added. The mixture is kept at this temperature for 30 minutes. The temperature is then raised to 160°C and kept at this temperature for 7 hours. Next, 7 parts by mass of o-cresol phenolic epoxy resin CNE704, 51 parts by mass of bisphenol F-type diglycidyl ether 170 epoxy resin, and 10 parts by mass of E51 are added. The mixture is kept at 140°C and kept at this temperature for 30 minutes. Then, the temperature is cooled to 120°C, and 39 parts by mass of acetone are added dropwise. Once the mixture is thoroughly mixed, dissolved, and transparent, the low-dielectric-rate, low-water-absorption epoxy resin is obtained. The product has a bromine content of 10.2% and an epoxy equivalent of 425 g / eq.

[0031] Examples 1-8: A method for preparing a low-dielectric, low-water-absorption epoxy resin includes the following steps: 3 parts by mass of TBBA, 42 parts by mass of bisphenol-type diglycidyl ether E51, 1 part by mass of tetraphenol ethane phenolic resin, 23 parts by mass of bisphenol AF, and 2 parts by mass of tetrafluorohydroquinone are added to a reactor. The mixture is heated to 85°C with stirring and maintained at this temperature for 3 hours. Then, the temperature is raised to 120°C, 0.5 parts by mass of catalyst are added, and the mixture is kept at this temperature for 30 minutes. The temperature is then raised to 185°C (and kept at this temperature) for 4.5 hours. Next, 8 parts by mass of phenolic epoxy, 15 parts by mass of bisphenol F-type diglycidyl ether 170, and 20 parts by mass of E54 are added. The mixture is kept at 140°C and the mixture is kept at this temperature for 30 minutes. Then, the temperature is cooled to 120°C, and 29 parts by mass of propylene glycol methyl ether are added dropwise. After mixing, dissolving, and becoming transparent, the low-dielectric, low-water-absorption epoxy resin is obtained. The product has a fluorine content of 11.8% and an epoxy equivalent of 395 g / eq.

[0032] The catalyst is one or a mixture of two of the following: imidazole, triphenylphosphine, triphenyl phosphate, triethylbenzylammonium chloride, tetrabutylammonium bromide, and butyltriphenylphosphine bromide; The phenolic epoxy resin is one or a mixture of two of the following: phenolic epoxy resin, bisphenol A phenolic epoxy resin, o-cresol phenolic epoxy resin, and DCPD (dicyclopentadiene) phenolic epoxy resin.

[0033] Examples 1-9: A method for preparing a low-dielectric, low-water-absorption epoxy resin involves adding 4 kg of TBBA, 28 kg of bisphenol diglycidyl ether resin, 3 kg of tetraphenol ethane phenolic resin, 22 kg of bisphenol AF, and 3 kg of tetrafluoroterephthalic acid to a reactor. The mixture is heated to 105°C with stirring and maintained at this temperature for 2 hours. Then, the temperature is raised to 125°C, 0.8 kg of catalyst is added, and the reaction is maintained for 30 minutes. The temperature is then raised to 165°C and maintained for 6.5 hours. Next, 6 kg of phenolic epoxy and 57 kg of bisphenol diglycidyl ether are added, and the reaction is maintained at 135°C for 30 minutes. The mixture is then cooled to 120°C, and 31 kg of solvent is added dropwise. After thorough mixing and dissolution to a transparent state, the low-dielectric, low-water-absorption epoxy resin is obtained. The product has a fluorine content of 9.0% and an epoxy equivalent of 426 g / eq. The bisphenol diglycidyl ether is one or a mixture of two of E51, E54, E12, E20, and N170; The catalyst is one or a mixture of two of the following: imidazole, triphenylphosphine, triphenyl phosphate, triethylbenzylammonium chloride, tetrabutylammonium bromide, and butyltriphenylphosphine bromide; The phenolic epoxy resin is one or a mixture of two of the following: phenolic epoxy resin, bisphenol A phenolic epoxy resin, o-cresol phenolic epoxy resin, and DCPD (dicyclopentadiene) phenolic epoxy resin.

[0034] The fluorinated hydroxy compound is one or a mixture of several of bisphenol AF, tetrafluoroterephthalic acid, and tetrafluorohydroquinone; The bisphenol diglycidyl ether is one or a mixture of two of E51 epoxy resin, E54 epoxy resin, E12, E20, and N170. The catalyst is one or a mixture of two of the following: imidazole, triphenylphosphine, triphenyl phosphate, triethylbenzylammonium chloride, tetrabutylammonium bromide, and butyltriphenylphosphine bromide; The phenolic epoxy resin is one or a mixture of two of the following: phenolic epoxy resin, bisphenol A phenolic epoxy resin, o-cresol phenolic epoxy resin, and DCPD (dicyclopentadiene) phenolic epoxy resin. The solvent is one of butanone, acetone, a mixture of butanone and propylene glycol methyl ether (in any proportion), or a mixture of acetone and propylene glycol methyl ether (in any proportion).

[0035] A method for preparing a low-dielectric, low-water-absorption epoxy resin composition includes the following steps: sequentially adding the aforementioned low-dielectric, low-water-absorption epoxy resin, low-hydroxyl epoxy resin, thixotropic agent, filler, phenolic epoxy resin, and catalyst, wherein the weight parts are 10-40 parts of low-dielectric, low-water-absorption epoxy resin, 10-20 parts of low-hydroxyl epoxy resin, 0-5 parts of thixotropic agent, 0-140 parts of filler, 1-5 parts of phenolic epoxy resin, 0.5-5 parts of active ester curing agent, and 10-15 parts by weight of methyl ethyl ketone, respectively; and stirring at high speed at room temperature (25℃-30℃) for 30 minutes until the materials are evenly mixed to obtain the low-dielectric, low-water-absorption epoxy resin composition.

[0036] The low dielectric and low water absorption epoxy resins described in Examples 2-1 to 2-9 are the epoxy resins prepared in Examples 1-1 to 1-9 above, with a solid content of 79% to 81%, an epoxy equivalent of 380 to 430 g / eq, and a fluorine content of 9% to 13%. The low-hydroxyl epoxy resin is a low-hydroxyl epoxy resin with a mass percentage content of 69% to 71% and a hydroxyl equivalent of 5000 to 10000. The phenolic epoxy resin is one or a mixture of two of the following: phenolic epoxy resin, bisphenol A phenolic epoxy resin, o-cresol phenolic epoxy resin, and DCPD (dicyclopentadiene) phenolic epoxy resin. The thixotropic agent is one or a mixture of two of fumed silica and surface-treated fumed silica; The filler is molten spherical silica powder, and the average particle size D95 of the filler is ≤15 micrometers; The curing agent is an active ester curing agent, specifically one or more of the following: DFE616, DFE617, DFE617L, or DFE618 from Dongcai Technology Group Co., Ltd.

[0037] In the above embodiments: unless otherwise specified, the percentage examples used are mass (weight) percentage examples or percentage examples known to those skilled in the art; unless otherwise specified, the proportions used are mass (weight) proportions; the mass (weight) parts are all grams or kilograms.

[0038] In the above embodiments, the process parameters (temperature, time, etc.) and the values ​​of each component dosage in each step are ranges, and any point can be applied.

[0039] The technical contents of this invention and the above embodiments that are not specifically described are the same as those of the prior art, and the raw materials are all commercially available products.

[0040] The present invention is not limited to the above embodiments; all embodiments described herein can be implemented and have the aforementioned good effects.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-dielectric-content, low-water-absorption epoxy resin composition, characterized in that, The resin composition is mainly made of low dielectric and low water absorption epoxy resin, low hydroxyl epoxy resin, thixotropic agent, filler, phenolic epoxy resin, active ester curing agent and methyl ethyl ketone (MEK), with the following weight proportions: 10-40 parts low dielectric and low water absorption epoxy resin, 10-20 parts low hydroxyl epoxy resin, 0-5 parts thixotropic agent, 0-140 parts filler, 1-5 parts phenolic epoxy resin, 40-50 parts active ester curing agent and 60-85 parts MEK. The preparation of the low dielectric and low water absorption epoxy resin includes the following steps: S1. Add 1-5 parts by weight of TBBA, 15-25 parts by weight of fluorinated hydroxyl compound, 35-55 parts by weight of bisphenol diglycidyl ether, and 1-3 parts by weight of tetraphenol ethane phenolic resin to the reactor, and heat to 80℃-110℃ with stirring, and maintain the temperature for 1.5-3.5h. S2. Then, heat the mixture to 120℃~150℃ and add 0.2~1 part by mass of catalyst, and maintain the temperature for the reaction. S3. Then heat to 160℃~190℃ and react for 4~7h. Then add 25~60 parts by weight of bisphenol diglycidyl ether and 5~9 parts by weight of phenolic epoxy resin, and keep the temperature at 120℃~140℃ for the reaction. S4. Then cool to 100℃~120℃, add 25~40 parts by mass of solvent, and wait until it is mixed, dissolved and transparent to obtain low dielectric and low water absorption epoxy resin. The fluorinated hydroxy compound is one or a mixture of several of bisphenol AF, tetrafluoroterephthalic acid, and tetrafluorohydroquinone; The low-hydroxyl epoxy resin uses MDI to cap the hydroxyl groups in the system, and the product is a low-hydroxyl epoxy resin with a mass percentage content of 70±1% and a hydroxyl equivalent of 5000 to 10000.

2. The low dielectric and low water absorption epoxy resin composition according to claim 1, characterized in that, The bisphenol diglycidyl ether is one or a mixture of two of E51 epoxy resin, E54 epoxy resin, N-170 epoxy, E12, and E20.

3. The low dielectric and low water absorption epoxy resin composition according to claim 1, characterized in that, The catalyst is one or a mixture of two of the following: imidazole, triphenylphosphine, triphenyl phosphate, triethylbenzylammonium chloride, tetrabutylammonium bromide, and butyltriphenylphosphine bromide.

4. The low dielectric and low water absorption epoxy resin composition according to claim 1, characterized in that, The phenolic epoxy resin is one or a mixture of two of the following: phenolic epoxy resin, bisphenol A phenolic epoxy resin, o-cresol phenolic epoxy resin, and DCPD phenolic epoxy resin.

5. The low dielectric and low water absorption epoxy resin composition according to claim 1, characterized in that, The solvent is one of butanone, acetone, a mixture of butanone and propylene glycol methyl ether, or a mixture of acetone and propylene glycol methyl ether.

6. The low dielectric and low water absorption epoxy resin composition according to claim 1, characterized in that, The thixotropic agent is one or a mixture of several of fumed silica and surface-treated fumed silica; the filler is molten spherical silica powder with an average particle size D95 ≤ 15 micrometers; the active ester curing agent is one or a combination of several of DFE616, DFE617, DFE617L or DFE618 from Dongcai Technology Group Co., Ltd.

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