Brominated epoxy resin, environment-friendly brominated epoxy resin formula and preparation method thereof

Abstract

The invention relates to the technical field of epoxy resin, and particularly discloses brominated epoxy resin, and an environment-friendly brominated epoxy resin formula and a preparation method thereof. The formula of the environment-friendly brominated epoxy resin comprises 100 parts of brominated epoxy resin, 5-10 parts of nano toughened epoxy resin, 5-10 parts of o-cresol formaldehyde epoxy resin, 10-30 parts of a curing agent, 0.1-1 part of a curing agent accelerant, 15-20 parts of dimethyl sulfoxide, 5-10 parts of silica powder and 30-50 parts of filler. The preparation method of the brominated epoxy resin comprises the following steps: heating and uniformly mixing a brominated epoxy resin oligomer, tetrabromobisphenol A and tribromophenol at 140-160 DEG C, adding a composite catalyst, and prepolymerizing under a microwave condition to obtain a brominated epoxy resin prepolymer; and mixing the brominated epoxy resin prepolymer with a single catalyst, and polymerizing under a microwave condition to obtain the brominated epoxy resin. The epoxy resin formula provided by the invention has excellent mechanical strength, electrical insulation performance and heat resistance after being cured.

Description

Technical Field

[0001] The present application relates to the technical field of epoxy resins. More specifically, it relates to a brominated epoxy resin, an environmentally friendly brominated epoxy resin formulation and a preparation method thereof. Background Art

[0002] With the increasing attention of society to environmental protection and the in-depth implementation of the concept of sustainable development, the research and development and application of environmentally friendly materials have become an important topic in the chemical industry. As an important polymer material, epoxy resin has been widely used in the fields of electronics and electricity, coatings, composite materials, etc. due to its excellent mechanical properties, electrical insulation properties and adhesiveness. However, the traditional epoxy resin has poor flame retardancy. To improve its flame retardancy, bromine-containing compounds are usually added. Brominated epoxy resin has been widely used in engineering plastic modified materials due to its good thermal stability, heat aging resistance and processing properties, especially excellent ultraviolet resistance.

[0003] However, there are some problems with the existing brominated epoxy resins. For example, in the traditional preparation method, the use of tetrabromobisphenol A is highly controversial, and its residual amount is difficult to control, which may cause environmental pollution and health risks. In addition, the molecular weight distribution of brominated epoxy resins in the prior art is relatively wide and difficult to accurately control, resulting in unstable performance. For example, although low molecular weight brominated epoxy resin has good adhesiveness and flame retardancy, its stability and mechanical properties at high temperatures are poor.

[0004] To solve these problems, researchers are committed to developing environmentally friendly brominated epoxy resin formulations. On the one hand, by improving the production process, the residual amount of tetrabromobisphenol A is reduced to meet international environmental protection requirements. On the other hand, by optimizing the formulation and process, the molecular weight and performance stability of brominated epoxy resin are improved. For example, the use of composite catalysts and new synthesis processes can effectively control the molecular weight of brominated epoxy resin and improve its toughness and impact resistance.

[0005] In addition, the development of environmentally friendly brominated epoxy resins also needs to consider their performance in actual applications. For example, in the field of electronics and electricity, it is necessary to ensure the insulation performance and heat resistance of the material; in the field of coatings, its adhesion and weather resistance need to be considered. Therefore, developing an environmentally friendly and high-performance brominated epoxy resin formulation is of great significance for meeting the high requirements of modern industry for materials. Summary of the Invention

[0006] To solve the above technical problems, the present application provides a brominated epoxy resin, an environmentally friendly brominated epoxy resin formulation and a preparation method thereof. The brominated epoxy resin provided by the present application adopts an environmentally friendly and green composite catalyst system and is prepared by means of microwave-assisted synthesis technology. It has a short preparation time, high product purity, stable performance and is more environmentally friendly. Using this brominated epoxy resin as the matrix resin and compounding it with nano-toughened epoxy resin and o-cresol novolac epoxy resin, after curing treatment, the obtained material exhibits excellent high mechanical strength, and at the same time has excellent electrical insulation performance and heat resistance.

[0007] In the first aspect, the present application provides a preparation method of a brominated epoxy resin, adopting the following technical scheme: A preparation method of a brominated epoxy resin, comprising the following preparation steps: Mix the brominated epoxy resin oligomer, tetrabromobisphenol A and tribromophenol uniformly by heating at 140-160 °C, add a composite catalyst, and pre-polymerize under microwave conditions to obtain a brominated epoxy resin prepolymer; Mix the brominated epoxy resin prepolymer with a single catalyst and polymerize under microwave conditions to obtain a brominated epoxy resin.

[0008] The brominated epoxy resin oligomer used in the present application can be self-made or purchased commercially. The molecular weight is mainly between 1000 and 10000. Using tribromophenol for end-capping and adopting a composite catalyst and microwave-assisted synthesis technology, a brominated epoxy resin with a molecular weight of 30000-50000 can be obtained in a short time.

[0009] Further, the mass ratio of the brominated epoxy resin oligomer, tetrabromobisphenol A and tribromobisphenol is 1:(0.8-0.85):(0.02-0.03), preferably 1:0.82:0.03.

[0010] Further, the composite catalyst is composed of 1-butyl-3-methylimidazolium acetate and tetramethyl titanate mixed in a mass ratio of 1:(0.8-1.2), preferably 1:1.

[0011] Further, based on the mass of the brominated epoxy resin oligomer, the dosage of the composite catalyst is 0.03-0.05 wt%, preferably 0.04 wt%.

[0012] Further, the single catalyst uses 1-vinylimidazole.

[0013] Further, based on the mass of the brominated epoxy resin prepolymer, the dosage of the single catalyst is 0.01-0.03 wt%, preferably 0.02 wt%.

[0014] Furthermore, the microwave conditions for preparing the brominated epoxy resin prepolymer are as follows: frequency 2 - 2.5 GHz, power 500 - 1000 W, reaction temperature 140 - 160 °C, and reaction time 10 - 30 min.

[0015] Furthermore, the microwave conditions for preparing the brominated epoxy resin are as follows: frequency 2 - 2.5 GHz, power 500 - 1000 W, reaction temperature 140 - 160 °C, and reaction time 10 - 30 min.

[0016] Under the above microwave reaction conditions, the raw materials react completely, there is no residue of tetrabromobisphenol A, and the preparation temperature is low and the time is short, reducing the 2 - 4 h required under conventional heating conditions to within 30 min.

[0017] In the second aspect, the present application provides an environmentally friendly brominated epoxy resin formulation, adopting the following technical solution: An environmentally friendly brominated epoxy resin formulation includes the following components in parts by weight: 100 parts of brominated epoxy resin, 5 - 10 parts of nano - toughened epoxy resin, 5 - 10 parts of o - cresol novolac epoxy resin, 10 - 30 parts of curing agent, 0.1 - 1 part of curing agent accelerator, 15 - 20 parts of dimethyl sulfoxide, 5 - 10 parts of silica powder, and 30 - 50 parts of filler. The brominated epoxy resin is obtained by the above preparation method.

[0018] The nano - toughened epoxy resin is a high - performance epoxy resin toughened by nanotechnology. By adding nanomaterials, the impact resistance and fracture toughness of the epoxy resin are significantly improved, and it has good heat resistance and can still maintain good performance in high - temperature environments. The o - cresol novolac epoxy resin has a multi - epoxy group structure in its molecular structure. After curing, many cross - links are formed densely, and the cured product has excellent thermal stability, mechanical strength, electrical insulation, and chemical resistance.

[0019] Further, the curing agent adopts at least one of amine - type curing agents and anhydride - type curing agents.

[0020] Among them, the amine - type curing agent can specifically be selected from aliphatic amines such as ethylenediamine, diethylenetriamine, polyethylenepolyamine, etc.; or aromatic amines such as m - phenylenediamine, m - xylylenediamine, etc.; or amine - modified curing agents such as T31 curing agent, phenolic amino alcohol curing agent, etc. The anhydride - type curing agent can specifically be selected from organic acid anhydrides such as maleic anhydride, phthalic anhydride, etc.

[0021] Further, the curing agent accelerator is selected from one or a combination of phenolic accelerators, imidazole accelerators, amine accelerators, and Lewis acid accelerators.

[0022] Among them, phenolic accelerators include but are not limited to phenol, resorcinol, nonylphenol, bisphenol A, 2,4,6-tris(dimethylaminomethyl)phenol, etc.; amine accelerators include but are not limited to o-hydroxybenzyldimethylamine, triethylamine, triethanolamine, benzyldimethylamine, alkyltrimethylammonium bromide salts, etc.; imidazole accelerators include but are not limited to 2-methylimidazole, 2-phenylimidazole, etc.; Lewis acid accelerators include but are not limited to BF 3 , SnCl 4 , AlCl 3 , FeCl 3 , TiCl 4 , and ZnCl 2 , etc.

[0023] Furthermore, the filler is selected from at least one of graphene, silica, titanium dioxide, alumina, and aluminum hydroxide.

[0024] In a third aspect, the present application provides a preparation method for an environmentally friendly brominated epoxy resin formulation, adopting the following technical solution: A preparation method for an environmentally friendly brominated epoxy resin formulation includes the following preparation steps: Mix and stir evenly brominated epoxy resin, nano-toughened epoxy resin, o-cresol novolac epoxy resin, curing agent, curing agent accelerator, dimethyl sulfoxide, silica powder, and filler to obtain an environmentally friendly brominated epoxy resin formulation that can be directly cured for use.

[0025] To sum up, the beneficial effects of the present application are as follows: The present application uses brominated epoxy resin as the matrix resin, and is compounded with nano-toughened epoxy resin and o-cresol novolac epoxy resin. After curing treatment, the obtained material exhibits excellent high mechanical strength, and at the same time has excellent electrical insulation performance and heat resistance, and the comprehensive performance is significantly improved. In the process of preparing brominated epoxy resin, the present application adopts an environmentally friendly and green composite catalyst system, and creatively introduces microwave-assisted synthesis technology. Thanks to this advanced process, there is no residue of tetrabromobisphenol A in the final product, and the preparation time is short. Compared with traditional commercially available brominated epoxy resins, its environmental performance is greatly improved, providing a more green, efficient and excellent performance material choice for related fields. Specific Embodiments

[0026] The following specific examples illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation manners, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application.

[0027] In addition, it should be understood that one or more method steps mentioned in this application do not exclude the existence of other method steps before and after the combined steps or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. Moreover, unless otherwise specified, the numbers of the method steps are only convenient tools for identifying the method steps, rather than restricting the arrangement order of the method steps or limiting the scope of implementation of this application. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope of implementation of this application.

[0028] If the specific experimental conditions are not specified in the examples, they are usually in accordance with the conventional conditions in the art or the conditions recommended by the reagent company; the materials, reagents, etc. used in the examples, unless otherwise specified, can be obtained through commercial channels.

[0029] The brominated epoxy resin oligomer was purchased from Guangdong Shengke Biochemical Technology Co., Ltd., with a molecular weight of 1200.

[0030] The nano-toughened epoxy resin was purchased from Sinopec Hunan Petrochemical Co., Ltd., with the brand CYDN-128 and an epoxy equivalent of 200-220 g / eq.

[0031] The o-cresol novolac epoxy resin was purchased from Sinopec Hunan Petrochemical Co., Ltd., with the brand CYDCN-208 and an epoxy equivalent of 200-215 g / eq.

[0032] Preparation of brominated epoxy resin in Examples 1-9 Preparation of brominated epoxy resin in Example 1: Take the brominated epoxy resin oligomer, tetrabromobisphenol A and tribromophenol according to a weight ratio of 1:0.8:0.02, heat and mix them evenly at 140°C, add a composite catalyst composed of 1-butyl-3-methylimidazolium acetate and tetramethyl titanate mixed at a weight ratio of 1:0.8, and the dosage of the composite catalyst is 0.03% of the weight of the brominated epoxy resin oligomer. Pre-polymerize for 30 min under microwave conditions to obtain a brominated epoxy resin prepolymer; Mix the brominated epoxy resin prepolymer with 1-vinylimidazole, and the dosage of 1-vinylimidazole is 0.01% of the weight of the brominated epoxy resin prepolymer. Polymerize for 20 min under microwave conditions to obtain brominated epoxy resin.

[0033] The above microwave conditions are: frequency 2.45 GHz, power 550 W, reaction temperature 140°C.

[0034] Preparation of brominated epoxy resin in Example 2: The preparation method is the same as that in Example 1, except that the weight ratio of the brominated epoxy resin oligomer, tetrabromobisphenol A and tribromophenol is 1:0.82:0.03.

[0035] Example 3 Preparation of brominated epoxy resin: The preparation method is the same as that of Example 1, except that the weight ratio of the brominated epoxy resin oligomer, tetrabromobisphenol A, and tribromophenol is 1:0.85:0.03.

[0036] Example 4 Preparation of brominated epoxy resin: The preparation method is the same as that of Example 1, except that the composite catalyst is composed of 1-butyl-3-methylimidazolium acetate and tetramethyl titanate mixed in a weight ratio of 1:1.

[0037] Example 5 Preparation of brominated epoxy resin: The preparation method is the same as that of Example 1, except that the composite catalyst is composed of 1-butyl-3-methylimidazolium acetate and tetramethyl titanate mixed in a weight ratio of 1:1.2.

[0038] Example 6 Preparation of brominated epoxy resin: The preparation method is the same as that of Example 1, except that the amount of the composite catalyst used is 0.04% of the weight of the brominated epoxy resin oligomer.

[0039] Example 7 Preparation of brominated epoxy resin: The preparation method is the same as that of Example 1, except that the amount of the composite catalyst used is 0.05% of the weight of the brominated epoxy resin oligomer.

[0040] Example 8 Preparation of brominated epoxy resin: The preparation method is the same as that of Example 1, except that the amount of 1-vinylimidazole used is 0.02% of the weight of the brominated epoxy resin prepolymer.

[0041] Example 9 Preparation of brominated epoxy resin: The preparation method is the same as that of Example 1, except that the amount of 1-vinylimidazole used is 0.03% of the weight of the brominated epoxy resin prepolymer.

[0042] Comparative Example 1 Preparation of brominated epoxy resin: Take the brominated epoxy resin oligomer, tetrabromobisphenol A, and tribromophenol according to a weight ratio of 1:0.8:0.02, and heat and mix them evenly at 140 °C. Add a composite catalyst composed of 1-butyl-3-methylimidazolium acetate and tetramethyl titanate mixed in a weight ratio of 1:0.8. The amount of the composite catalyst used is 0.03% of the weight of the brominated epoxy resin oligomer. Heat up to 240 °C and react for 4 h to obtain a brominated epoxy resin prepolymer; Mix the brominated epoxy resin prepolymer with 1-vinylimidazole. The amount of 1-vinylimidazole used is 0.01% of the weight of the brominated epoxy resin prepolymer. Heat up to 240 °C and react for 2 h to obtain brominated epoxy resin.

[0043] Comparative Example 2 Preparation of brominated epoxy resin: Take brominated epoxy resin oligomer, tetrabromobisphenol A and tribromophenol according to the weight ratio of 1:0.8:0.02, heat and mix them evenly at 140 °C, add a composite catalyst composed of 1-vinylimidazole and tetramethyl titanate mixed at a weight ratio of 1:0.8, and the dosage of the composite catalyst is 0.03% of the weight of the brominated epoxy resin oligomer. Raise the temperature to 240 °C and react for 4 h to obtain a brominated epoxy resin prepolymer; Mix the brominated epoxy resin prepolymer with 1-vinylimidazole, and the dosage of 1-vinylimidazole is 0.01% of the weight of the brominated epoxy resin prepolymer. Raise the temperature to 240 °C and react for 2 h to obtain brominated epoxy resin.

[0044] Detect the brominated epoxy resins prepared in Examples 1-9 and Comparative Examples 1-2, and record the data of each index in Table 1 below. The molecular weight is measured by a gel permeation chromatograph, the bromine content is measured by the oxygen flask combustion method, and the residual amount of tetrabromobisphenol A is measured by a high performance liquid chromatograph.

[0045] Table 1 Performance indicators of brominated epoxy resin It can be seen from the test results in Table 1 that the weight average molecular weights of the brominated epoxy resins prepared in this application are all around 35,000, and tetrabromobisphenol A is not detected, indicating that the solution of this application has high feasibility and the obtained brominated epoxy resin has high environmental protection.

[0046] Examples 10-18 Preparation of environmentally friendly brominated epoxy resin formulations. The preparation steps are as follows: Mix brominated epoxy resin, nano-toughened epoxy resin, o-cresol novolac epoxy resin, dicyandiamide (Aradur ® 2844) latent curing agent, 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) curing agent accelerator, dimethyl sulfoxide, silica powder (average particle size 80 nm), and aluminum hydroxide filler (average particle size 10 μm) and stir evenly to obtain an environmentally friendly brominated epoxy resin formulation that can be directly cured and used.

[0047] Example 10 Environmentally friendly brominated epoxy resin formulation: 100 parts of brominated epoxy resin prepared in Example 1, 10 parts of nano-toughened epoxy resin, 10 parts of o-cresol novolac epoxy resin, Aradur ® 2844 curing agent 30 parts, DMP-30 curing agent accelerator 0.5 parts, dimethyl sulfoxide 20 parts, silica powder 10 parts, aluminum hydroxide 50 parts.

[0048] Example 11 Environmentally friendly brominated epoxy resin formulation: 100 parts of brominated epoxy resin prepared in Example 2, and the rest is the same as Example 10.

[0049] Example 12 Environmentally Friendly Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Example 3, and the rest is the same as in Example 10.

[0050] Example 13 Environmentally Friendly Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Example 4, and the rest is the same as in Example 10.

[0051] Example 14 Environmentally Friendly Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Example 5, and the rest is the same as in Example 10.

[0052] Example 15 Environmentally Friendly Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Example 6, and the rest is the same as in Example 10.

[0053] Example 16 Environmentally Friendly Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Example 7, and the rest is the same as in Example 10.

[0054] Example 17 Environmentally Friendly Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Example 8, and the rest is the same as in Example 10.

[0055] Example 18 Environmentally Friendly Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Example 9, and the rest is the same as in Example 10.

[0056] Comparative Example 3 Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Comparative Example 1, and the rest is the same as in Example 10.

[0057] Comparative Example 4 Brominated Epoxy Resin Formula: 100 parts of the brominated epoxy resin prepared in Comparative Example 2, and the rest is the same as in Example 10.

[0058] Comparative Example 5 Brominated Epoxy Resin Formula: 110 parts of the brominated epoxy resin prepared in Example 1, 10 parts of nano-toughened epoxy resin, Aradur ® 2844 curing agent 30 parts, DMP-30 curing agent accelerator 0.5 part, dimethyl sulfoxide 20 parts, silica powder 10 parts, aluminum hydroxide 50 parts.

[0059] Comparative Example 6 Brominated Epoxy Resin Formula: 110 parts of the brominated epoxy resin prepared in Example 1, 10 parts of o-cresol novolac epoxy resin, Aradur ® 2844 curing agent 30 parts, DMP-30 curing agent accelerator 0.5 part, dimethyl sulfoxide 20 parts, silica powder 10 parts, aluminum hydroxide 50 parts.

[0060] The brominated epoxy resin formula prepared in this application can be used for castings, laminates, adhesives, etc., especially for resin sheets, resin composite metal foils, prepregs, laminates, metal-clad laminates, and printed circuit boards, etc.

[0061] Performance Test: The 2116 type of electronic glass cloth was respectively impregnated with the brominated epoxy resin formulation solutions prepared in Examples 10 - 18 and Comparative Examples 3 - 6, and the solvent was removed at 150 °C to obtain prepreg specimens. Eight prepreg specimens and two one-ounce electrolytic copper foils were laminated together and laminated through a hot press to obtain a double-sided copper-clad laminate. The performance indicators of this laminate were detected and recorded in Table 2.

[0062] Test Indicators and Methods: Tg: Glass transition temperature, measured according to the DSC test method specified in IPC-TM-650 2.4.25.

[0063] Dielectric constant: Measured according to IPC-TM-650 2.5.5.13.

[0064] Immersion soldering resistance: The double-sided copper-clad laminate was immersed in a tin bath at a temperature of 288 °C for 20 seconds, then taken out and cooled to room temperature, and then immersed in the tin bath repeatedly 5 times, and then the immersion soldering resistance was evaluated by observing the appearance.

[0065] PCT: The copper-clad laminate was immersed in a copper etching solution to remove the surface copper foil to evaluate the substrate. The substrate was placed in a steam pressure cooker and treated at 121 °C and 2 atm for 2 hours, then immersed in a tin bath at a temperature of 288 °C, and the corresponding time was recorded when the substrate showed blistering or splitting. When the substrate did not show blistering or delamination in the tin bath for more than 5 minutes, the evaluation could be ended.

[0066] Td: The double-sided copper-clad laminate was immersed in a copper etching solution to remove the surface copper foil to evaluate the substrate. The substrate was tested using a thermogravimetric analyzer (TGA), and in a nitrogen atmosphere, it was heated at a rate of 10 °C / min, and the temperature value at 5% weight loss was reached.

[0067] Interlayer peel strength: Measured according to IPC-TM-650 2.4.8.

[0068] Number of non-delaminating layers through lead-free reflow soldering: Tested using TMA, with a heating rate of 10 °C / min and a peak temperature of 260 °C.

[0069] Table 2 Performance Indicators of Double-Sided Copper-Clad Laminates It can be seen from the test results in Table 2 that for the double-sided copper-clad laminates prepared in Examples 10 - 18 of this application, various performances such as dielectric constant, heat resistance, and immersion soldering resistance are excellent.

[0070] Compared with Example 10, the thermal decomposition temperature of Comparative Examples 3 and 4 is low and the thermal delamination time is short because a relatively high residual amount of tetrabromobisphenol A has a great negative impact on the heat resistance of the product.

[0071] Compared with Example 10, the performance of Comparative Examples 5 and 6 all decreases, and the interlayer delamination strength decreases the most, indicating the necessity of adding nano-toughened epoxy resin and o-cresol novolac epoxy resin to the formulation of the present application. The two epoxy resins can significantly improve the delamination strength after curing of the formulation.

[0072] The above are only the preferred embodiments of the present invention, and do not impose any formal or substantial limitations on the present invention. It should be pointed out that for those of ordinary skill in the art in the technical field, without departing from the method of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention. Those skilled in the art, without departing from the spirit and scope of the present invention, when making some changes, modifications and equivalent variations of evolution using the technical content disclosed above, are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments according to the substantial technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A brominated epoxy resin, characterized in that The brominated epoxy resin is obtained by the following preparation steps: The brominated epoxy resin oligomer, tetrabromobisphenol A and tribromophenol are heated and mixed at 140-160° C., a composite catalyst is added, and prepolymerized under microwave conditions to obtain a brominated epoxy resin prepolymer; The brominated epoxy resin prepolymer is mixed with a single catalyst and polymerized under microwave conditions to obtain a brominated epoxy resin; The microwave conditions are: frequency 2-2.5 GHz, power 500-1000 W, reaction temperature 140-160° C., and reaction time 10-30 min.

2. The brominated epoxy resin according to claim 1, characterized in that The mass ratio of the brominated epoxy resin oligomer, tetrabromobisphenol A and tribromobisphenol is 1:(0.8-0.85):(0.02-0.03).

3. The brominated epoxy resin according to claim 1, characterized in that The composite catalyst is composed of 1-butyl-3-methylimidazole acetate and tetramethyl titanate mixed in a mass ratio of 1:(0.8-1.2).

4. The brominated epoxy resin according to claim 3, characterized in that The amount of the composite catalyst used is 0.03-0.05wt% based on the mass of the brominated epoxy resin oligomer.

5. The brominated epoxy resin according to claim 1, characterized in that The single catalyst is 1-vinylimidazole, and the amount of the single catalyst used is 0.01-0.03 wt % based on the mass of the brominated epoxy resin prepolymer.

6. An environmentally friendly brominated epoxy resin formulation, characterized in that: The invention comprises the following components in parts by weight: 100 parts of the brominated epoxy resin according to any one of claims 1 to 5, 5 to 10 parts of nano-toughened epoxy resin, 5 to 10 parts of o-cresol epoxy resin, 10 to 30 parts of curing agent, 0.1 to 1 part of curing agent accelerator, 15 to 20 parts of dimethyl sulfoxide, 5 to 10 parts of silicon powder and 30 to 50 parts of filler.

7. The environmentally friendly brominated epoxy resin formulation according to claim 6, characterized in that: The curing agent is at least one of an amine curing agent and an acid anhydride curing agent.

8. The environmentally friendly brominated epoxy resin formulation according to claim 6, characterized in that: The curing agent accelerator is selected from one or more combinations of phenol accelerators, imidazole accelerators, amine accelerators, and Lewis acid accelerators.

9. The environmentally friendly brominated epoxy resin formulation according to claim 6, characterized in that: The filler is selected from at least one of graphene, silicon dioxide, titanium dioxide, aluminum oxide and aluminum hydroxide.

10. A method for preparing the environmentally friendly brominated epoxy resin formulation according to any one of claims 6 to 9, characterized in that: The preparation method comprises the following steps: mixing and evenly stirring brominated epoxy resin, nano-toughened epoxy resin, o-cresol epoxy resin, curing agent, curing agent accelerator, dimethyl sulfoxide, silicon micropowder and filler to obtain an environmentally friendly brominated epoxy resin formula that can be directly cured and used.

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