Epoxy resin glue solution for flame-retardant copper-clad plate and processing technology of epoxy resin glue solution

Abstract

The invention discloses an epoxy resin glue solution for a flame-retardant copper-clad plate, and particularly relates to the technical field of copper-clad plates, the epoxy resin glue solution comprises the following raw materials: bisphenol A epoxy resin, benzoxazine resin, an inorganic filler, a flame retardant, a diluent, a curing agent and an accelerant, and the inorganic filler is a mixture of modified magnesium hydroxide and modified barium sulfate. According to the invention, melamine cyanurate is modified by using pentaerythritol, zinc sulfate, zinc oxide, montmorillonite and borax, the pentaerythritol can improve the dispersion fluidity of melamine cyanurate, and then zinc sulfate, zinc oxide and borax are added, so that precipitated zinc borate microcrystals can be dispersed and deposited on the surface of melamine cyanurate; the melamine cyanurate containing the zinc borate microcrystals enters the interlayers of the montmorillonite, so that the interlayers of the montmorillonite are increased, a stripping type modified melamine cyanurate / montmorillonite compound is formed, and the flame retardant effect of the modified melamine cyanurate is better.

Description

Technical Field

[0001] The present invention relates to the technical field of copper clad laminates, and more specifically, the present invention relates to an epoxy resin adhesive solution for flame-retardant copper clad laminates and its processing technology. Background Art

[0002] As one of the basic materials of electronic circuits, the main functions of copper clad laminates are to connect and fix electronic components, and to achieve circuit conduction and signal transmission, etc. With the development of electronic technology, copper clad laminates have become an indispensable part of electronic products and are widely used in fields such as computers, communications, industrial control, and household appliances. However, with the continuous development of electronic technology, some problems and deficiencies have also emerged in copper clad laminates. For example, in a high-temperature environment, copper clad laminates are prone to deformation and failure; in high-frequency circuits, the transmission performance of copper clad laminates will also be affected; in addition, traditional copper clad laminates also have problems such as flammability and easy pollution, posing a certain threat to the environment and human health.

[0003] To solve these problems, epoxy resin adhesive solutions are widely used in the preparation of copper clad laminates. Epoxy resin adhesive solution is a kind of high molecular compound, which has good heat resistance, chemical corrosion resistance and mechanical strength, and can form a strong cross-linked structure for fixing and protecting electronic components. Since certain heat will be generated when the electronic circuit works, higher requirements are placed on the heat resistance and flame retardancy of copper clad laminates to ensure the safe and stable operation of the circuit.

[0004] However, the existing epoxy resin adhesive solution for copper clad laminates has poor flame retardant effect, resulting in low flame retardant performance of copper clad laminates and unable to meet people's usage requirements. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide an epoxy resin adhesive solution for flame-retardant copper clad laminates and its processing technology. The problem to be solved by the present invention is: how to improve the flame retardant performance of the epoxy resin adhesive solution, so as to improve the service life of the copper clad laminate.

[0006] To achieve the above object, the present invention provides the following technical solution: an epoxy resin adhesive solution for flame-retardant copper clad laminates, comprising the following raw materials in parts by weight: 60-80 parts of bisphenol A epoxy resin, 30-40 parts of benzoxazine resin, 10-20 parts of inorganic filler, 3-10 parts of flame retardant, 15-25 parts of diluent, 5-10 parts of curing agent, and 0.5-1.5 parts of accelerator.

[0007] In a preferred embodiment, it comprises the following raw materials in parts by weight: 65-75 parts of bisphenol A epoxy resin, 33-37 parts of benzoxazine resin, 13-17 parts of inorganic filler, 5-7 parts of flame retardant, 18-22 parts of diluent, 6-8 parts of curing agent, and 0.8-1.2 parts of accelerator.

[0008] In a preferred embodiment, it comprises the following raw materials in parts by weight: 70 parts of bisphenol A epoxy resin, 35 parts of benzoxazine resin, 15 parts of inorganic filler, 6 parts of flame retardant, 20 parts of diluent, 7 parts of curing agent and 1 part of accelerator.

[0009] In a preferred embodiment, the inorganic filler is a mixture of modified magnesium hydroxide and modified barium sulfate, and the weight ratio of the modified magnesium hydroxide to the modified barium sulfate is 1:(0.3 - 1.2). The diluent is a mixture of acetone and polypropylene glycol diglycidyl ether, and the mass ratio of the acetone to the polypropylene glycol diglycidyl ether is 1:(1 - 1.5). The curing agent is 2-methylimidazole, and the accelerator is DMP-30.

[0010] In a preferred embodiment, the preparation method of the modified magnesium hydroxide and the modified barium sulfate is as follows: Add DMF solution to the weighed magnesium hydroxide and barium sulfate, heat and stir evenly, then add sodium oleate and sodium undecylenate, and stir at a constant temperature for 2 - 4 h under ultrasonic assistance. After the reaction, evaporate and concentrate under pressure, filter, wash, and dry to obtain the modified magnesium hydroxide and the modified barium sulfate.

[0011] In a preferred embodiment, the addition amounts of the sodium oleate and the sodium undecylenate are respectively (0.2 - 0.4) and (0.1 - 0.3) of the sum of the masses of the modified magnesium hydroxide and the modified barium sulfate. The frequency during ultrasonic assistance is 90 - 120 KHz, and the temperature during constant temperature stirring is 70 - 80 °C.

[0012] In a preferred embodiment, the preparation method of the flame retardant is as follows: Weigh 50 - 100 parts of pentaerythritol, add it to 300 - 600 parts of water and stir to dissolve, then add 100 - 200 parts of melamine and 20 - 80 parts of sodium hydroxide solution and heat to dissolve. After heating to 80 - 100 °C, add 120 - 260 parts of cyanuric acid, 30 - 60 parts of zinc sulfate, 30 - 60 parts of zinc oxide and 40 - 80 parts of montmorillonite solution in sequence. After keeping warm and stirring for 1 - 2 h, add 10 - 30 parts of borax solution, continue to react for 2 - 3 h to obtain a white viscous product, and obtain the flame retardant after suction filtration, washing, drying and pulverizing.

[0013] In a preferred embodiment, the preparation method of the montmorillonite solution is as follows: Add 5000 ml of ethanol to 50 g of montmorillonite, stir and react at 60 - 80 °C for 3 - 6 h, and the ethanol evaporates and refluxes during the heating reaction process.

[0014] The present invention also provides a processing technology for an epoxy resin adhesive solution for a flame-retardant copper clad laminate, which specifically comprises the following steps:

[0015] Step 1: Weigh the raw materials according to the above parts by weight. Mix the weighed bisphenol A epoxy resin, benzoxazine resin and diluent evenly, and then heat up to 80 - 90 °C and add the flame retardant and inorganic filler to obtain a premix.

[0016] Step 2: Add the curing agent and accelerator to the premix and mix evenly to obtain the epoxy resin adhesive solution for flame - retardant copper - clad laminates.

[0017] The present invention also provides an application of the epoxy resin adhesive solution for flame - retardant copper - clad laminates, including the following steps:

[0018] Spray the epoxy resin adhesive solution on the surface of the flame - retardant copper - clad laminate, cure it at 80 - 100 °C. After complete curing for 1 - 3 h, carry out grinding and cleaning to form a cured layer.

[0019] The technical effects and advantages of the present invention:

[0020] 1. For the epoxy resin adhesive solution for flame - retardant copper - clad laminates produced by the present invention, by adding benzoxazine resin, inorganic filler and flame retardant, the benzoxazine resin can be stirred and mixed with the epoxy resin, which can improve the flame - retardant performance of the epoxy resin. And the added flame retardant is modified melamine cyanurate, which is modified with pentaerythritol, zinc sulfate, zinc oxide, montmorillonite and borax. Pentaerythritol can improve the dispersion fluidity of melamine cyanurate, and then adding zinc sulfate, zinc oxide and borax can make the precipitated zinc borate microcrystals disperse and deposit on the surface of melamine cyanurate. The melamine cyanurate containing zinc borate microcrystals enters the interlayer of montmorillonite, increasing the interlayer spacing of montmorillonite to form a exfoliated modified melamine cyanurate / montmorillonite composite, making the flame - retardant effect of the modified melamine cyanurate better.

[0021] 2. The inorganic filler added in the present invention is composed of modified magnesium hydroxide and barium sulfate. After being modified with sodium oleate and sodium undecylenate, the dispersion of magnesium hydroxide and barium sulfate in the epoxy resin is better, and the double bonds contained in sodium oleate and sodium undecylenate can form a chemical cross - linked structure with the epoxy resin, making the flame - retardant effect of the epoxy resin adhesive solution better. Specific Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention.

[0023] Example 1:

[0024] The present invention provides an epoxy resin adhesive solution for flame-retardant copper clad laminates, which comprises the following raw materials in parts by weight: 60 parts of bisphenol A epoxy resin, 30 parts of benzoxazine resin, 10 parts of inorganic filler, 3 parts of flame retardant, 15 parts of diluent, 5 parts of curing agent and 0.5 part of accelerator.

[0025] In a preferred embodiment, the inorganic filler is a mixture of modified magnesium hydroxide and modified barium sulfate, and the weight ratio of the modified magnesium hydroxide to the modified barium sulfate is 1:0.8. The diluent is a mixture of acetone and polypropylene glycol diglycidyl ether, and the mass ratio of the acetone to the polypropylene glycol diglycidyl ether is 1:1.3. The curing agent is 2-methylimidazole, and the accelerator is DMP-30.

[0026] In a preferred embodiment, the preparation method of the modified magnesium hydroxide and the modified barium sulfate is as follows: DMF solution is added to the weighed magnesium hydroxide and barium sulfate, and after heating and stirring evenly, sodium oleate and sodium undecylenate are added. Under the ultrasonic assistance, the mixture is stirred at a constant temperature for 2-4 h. After the reaction is completed, it is subjected to autoclave concentration, filtration, washing and drying to obtain the modified magnesium hydroxide and the modified barium sulfate.

[0027] In a preferred embodiment, the addition amounts of the sodium oleate and the sodium undecylenate are 0.3 and 0.2 respectively based on the sum of the masses of the modified magnesium hydroxide and the modified barium sulfate. The frequency during the ultrasonic assistance is 110 KHz, and the temperature during the constant temperature stirring is 75 °C.

[0028] In a preferred embodiment, the preparation method of the flame retardant is as follows: 80 parts of pentaerythritol are weighed and added to 500 parts of water and stirred to dissolve. Then 150 parts of melamine and 50 parts of sodium hydroxide solution are added and heated to dissolve. After heating to 90 °C, 200 parts of cyanuric acid, 45 parts of zinc sulfate, 45 parts of zinc oxide and 60 parts of montmorillonite solution are added in sequence. After keeping warm and stirring for 1.5 h, 20 parts of borax solution are added, and after continuing to react for 2.5 h, a white viscous product is obtained. After filtration, washing, drying and pulverization, the flame retardant is obtained.

[0029] In a preferred embodiment, the preparation method of the montmorillonite solution is as follows: 50 g of montmorillonite is added to 5000 ml of ethanol, and the mixture is stirred and reacted at 70 °C for 4.5 h. During the heating reaction, the ethanol evaporates and refluxes.

[0030] The present invention also provides a processing technology for the epoxy resin adhesive solution for flame-retardant copper clad laminates, which specifically comprises the following steps:

[0031] Step 1: Weigh the raw materials according to the above parts by weight, mix the weighed bisphenol A epoxy resin, benzoxazine resin and diluent evenly, and then heat to 85 °C and add the flame retardant and the inorganic filler to obtain a premix.

[0032] Step 2: Add a curing agent and an accelerator to the premix and mix evenly to obtain an epoxy resin adhesive solution for a flame-retardant copper clad laminate.

[0033] The present invention also provides an application of an epoxy resin adhesive solution for a flame-retardant copper clad laminate, including the following steps:

[0034] Spray the epoxy resin adhesive solution on the surface of the flame-retardant copper clad laminate, cure it at 90 °C, and after complete curing for 2 h, perform grinding and cleaning to form a cured layer.

[0035] Example 2:

[0036] Different from Example 1, an epoxy resin adhesive solution for a flame-retardant copper clad laminate includes the following raw materials in parts by weight: 70 parts of bisphenol A epoxy resin, 35 parts of benzoxazine resin, 15 parts of inorganic filler, 6 parts of flame retardant, 20 parts of diluent, 7 parts of curing agent, and 1 part of accelerator.

[0037] Example 3:

[0038] Different from both Example 1 and Example 2, an epoxy resin adhesive solution for a flame-retardant copper clad laminate includes the following raw materials in parts by weight: 80 parts of bisphenol A epoxy resin, 40 parts of benzoxazine resin, 20 parts of inorganic filler, 10 parts of flame retardant, 25 parts of diluent, 10 parts of curing agent, and 1.5 parts of accelerator.

[0039] Example 4:

[0040] The present invention provides an epoxy resin adhesive solution for a flame-retardant copper clad laminate, including the following raw materials in parts by weight: 60 parts of bisphenol A epoxy resin, 30 parts of benzoxazine resin, 10 parts of inorganic filler, 3 parts of flame retardant, 15 parts of diluent, 5 parts of curing agent, and 0.5 part of accelerator.

[0041] In a preferred embodiment, the inorganic filler is a mixture of magnesium hydroxide and barium sulfate, and the weight ratio of magnesium hydroxide to barium sulfate is 1:0.8. The diluent is a mixture of acetone and polypropylene glycol diglycidyl ether, and the mass ratio of acetone to polypropylene glycol diglycidyl ether is 1:1.3. The curing agent is 2-methylimidazole, and the accelerator is DMP-30.

[0042] In a preferred embodiment, the preparation method of the flame retardant is as follows: Weigh 80 parts of pentaerythritol, add it to 500 parts of water and stir to dissolve. Then add 150 parts of melamine and 50 parts of sodium hydroxide solution and heat to dissolve. After heating to 90 °C, add 200 parts of cyanuric acid, 45 parts of zinc sulfate, 45 parts of zinc oxide and 60 parts of montmorillonite solution in sequence. After keeping warm and stirring for 1.5 h, add 20 parts of borax solution, continue to react for 2.5 h to obtain a white viscous product, and obtain the flame retardant after suction filtration, washing, drying and pulverization.

[0043] In a preferred embodiment, the preparation method of the montmorillonite solution is as follows: Add 5000 ml of ethanol to 50 g of montmorillonite, stir and react at 70 °C for 4.5 h, and the ethanol evaporates and refluxes while heating and reacting.

[0044] The present invention also provides a processing technology for an epoxy resin adhesive solution for flame-retardant copper clad laminates, which specifically includes the following steps:

[0045] Step 1: Weigh the raw materials according to the above weight parts, mix the weighed bisphenol A epoxy resin, benzoxazine resin and diluent evenly, and then heat to 85 °C and add the flame retardant and inorganic filler to obtain a premix;

[0046] Step 2: Add a curing agent and an accelerator to the premix and mix evenly to obtain an epoxy resin adhesive solution for flame-retardant copper clad laminates.

[0047] The present invention also provides an application of an epoxy resin adhesive solution for flame-retardant copper clad laminates, including the following steps:

[0048] Spray the epoxy resin adhesive solution on the surface of the flame-retardant copper clad laminate, cure at 90 °C, and after complete curing for 2 h, perform grinding and cleaning to form a cured layer.

[0049] Example 5:

[0050] The present invention provides an epoxy resin adhesive solution for flame-retardant copper clad laminates, including the following raw materials in weight parts: 60 parts of bisphenol A epoxy resin, 30 parts of benzoxazine resin, 10 parts of inorganic filler, 3 parts of flame retardant, 15 parts of diluent, 5 parts of curing agent and 0.5 part of accelerator.

[0051] In a preferred embodiment, the inorganic filler is a mixture of modified magnesium hydroxide and modified barium sulfate, and the weight ratio of the modified magnesium hydroxide to the modified barium sulfate is 1:0.8. The diluent is a mixture of acetone and polypropylene glycol diglycidyl ether, and the mass ratio of the acetone to the polypropylene glycol diglycidyl ether is 1:1.3. The curing agent is 2-methylimidazole, and the accelerator is DMP-30.

[0052] In a preferred embodiment, the preparation methods of the modified magnesium hydroxide and the modified barium sulfate are as follows: Add a DMF solution to the weighed magnesium hydroxide and barium sulfate, heat and stir evenly, then add sodium oleate and sodium undecylenate, and stir at a constant temperature for 2 - 4 h under ultrasonic assistance. After the reaction, carry out autoclave concentration, filtration, washing, and drying to obtain the modified magnesium hydroxide and the modified barium sulfate.

[0053] In a preferred embodiment, the addition amounts of the sodium oleate and the sodium undecylenate are 0.3 and 0.2 respectively based on the sum of the masses of the modified magnesium hydroxide and the modified barium sulfate, the frequency during ultrasonic assistance is 110 KHz, and the temperature during constant temperature stirring is 75 °C.

[0054] In a preferred embodiment, the flame retardant is melamine cyanurate.

[0055] The present invention also provides a processing technology for an epoxy resin adhesive solution for flame - retardant copper - clad laminates, which specifically includes the following steps:

[0056] Step 1: Weigh the raw materials according to the above weight parts, mix the weighed bisphenol A epoxy resin, benzoxazine resin, and diluent evenly, and then raise the temperature to 85 °C and add the flame retardant and inorganic filler to obtain a premix.

[0057] Step 2: Add a curing agent and an accelerator to the premix and mix evenly to obtain the epoxy resin adhesive solution for flame - retardant copper - clad laminates.

[0058] The present invention also provides an application of the epoxy resin adhesive solution for flame - retardant copper - clad laminates, including the following steps:

[0059] Spray the epoxy resin adhesive solution on the surface of the flame - retardant copper - clad laminate, cure at 90 °C, and after complete curing for 2 h, carry out grinding and cleaning to form a cured layer.

[0060] Comparative example:

[0061] The present invention provides an epoxy resin adhesive solution for flame - retardant copper - clad laminates, which includes the following raw materials in weight parts: 60 parts of bisphenol A epoxy resin, 30 parts of benzoxazine resin, 10 parts of inorganic filler, 3 parts of flame retardant, 15 parts of diluent, 5 parts of curing agent, and 0.5 part of accelerator.

[0062] In a preferred embodiment, the inorganic filler is a mixture of magnesium hydroxide and barium sulfate, and the weight ratio of the magnesium hydroxide to the barium sulfate is 1:0.8; the diluent is a mixture of acetone and polypropylene glycol diglycidyl ether, and the mass ratio of the acetone to the polypropylene glycol diglycidyl ether is 1:1.3; the curing agent is 2 - methylimidazole, and the accelerator is DMP - 30.

[0063] In a preferred embodiment, the flame retardant is melamine cyanurate.

[0064] The present invention also provides a processing technology for an epoxy resin adhesive solution for flame-retardant copper clad laminates, specifically including the following steps:

[0065] Step 1: Weigh the raw materials according to the above weight parts, mix the weighed bisphenol A epoxy resin, benzoxazine resin and diluent evenly, and then heat up to 85 °C and add the flame retardant and inorganic filler to obtain a premix.

[0066] Step 2: Add a curing agent and an accelerator to the premix and mix evenly to obtain an epoxy resin adhesive solution for flame-retardant copper clad laminates.

[0067] The present invention also provides an application of an epoxy resin adhesive solution for flame-retardant copper clad laminates, including the following steps:

[0068] Spray the epoxy resin adhesive solution on the surface of the flame-retardant copper clad laminate, cure it at 90 °C, and after complete curing for 2 h, perform grinding and cleaning to form a cured layer.

[0069] Take the epoxy resin adhesive solutions prepared in the above Examples 1-5 as samples, namely Experimental Group 1, Experimental Group 2, Experimental Group 3, Experimental Group 4 and Experimental Group 5 respectively, and take the epoxy resin adhesive solution prepared in the control group as the control group, and detect the performance of the selected epoxy resin adhesive solution and record the detection results:

[0070] Determine the flame retardancy according to the vertical burning method of GB / T2408-2008 "Plastics - Determination of burning behavior - Horizontal and vertical methods". Experimental steps: Pour the epoxy resin adhesive solution into a mold with dimensions of 150 mm × 60 mm × 4 mm, cure it at room temperature for 24 - 48 h, cut it into rectangular strips with a sample size of 80 mm × 10 mm × 4 mm, place the sample in the testing equipment, and ignite its lower end. The testing equipment will record the combustion process of the sample and classify it into different grades according to its performance. The V-0 grade means that the material does not drip sparks, the combustion process time is less than 10 seconds, and the flame height is less than 50 mm; the V-1 grade means that during the combustion process of the material, the flame height is less than 50 mm, the combustion time does not exceed 30 seconds, and there are no obvious dripping sparks; the V-2 grade means that during the combustion process of the material, the flame height is less than 50 mm, the combustion time does not exceed 30 seconds, there are dripping sparks, but the number of sparks is not large, and the paper is not ignited.

[0071] The heat resistance was measured by a thermogravimetric analyzer. Experimental procedure: The epoxy resin glue was prepared into a uniform sample, and the air bubbles were removed by vacuum degassing. The size of the specimen was between 10 mg. The sample was placed in a nitrogen atmosphere and heated at a heating rate between 10 °C / min, with an initial temperature of 25 °C, and heated to 550 °C. The experimental data are recorded in Table 1 as follows.

[0072]

[0073]

[0074] Table 1

[0075] As can be seen from Table 1, the epoxy resin glue produced by the present invention has good flame retardancy. In Example 4, unmodified inorganic fillers were used, and its Tg temperature decreased slightly. In Example 5, unmodified flame retardants were used, and both its flame retardancy and Tg temperature decreased. Therefore, the added flame retardant is modified melamine cyanurate, which is modified with pentaerythritol, zinc sulfate, zinc oxide, montmorillonite and borax. Pentaerythritol can improve the dispersion fluidity of melamine cyanurate, and then zinc sulfate, zinc oxide and borax are added, which can make the precipitated zinc borate microcrystals disperse and deposit on the surface of melamine cyanurate. The melamine cyanurate containing zinc borate microcrystals enters the interlayer of montmorillonite, increasing the interlayer spacing of montmorillonite and forming a exfoliated modified melamine cyanurate / montmorillonite composite, making the flame retardant effect of the modified melamine cyanurate better. Magnesium hydroxide and barium sulfate have better dispersion in epoxy resin after being modified with sodium oleate and sodium undecylenate, and the double bonds contained in sodium oleate and sodium undecylenate can form a chemical cross-linking structure with epoxy resin, making the flame retardant effect of the epoxy resin glue better.

[0076] Finally: The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An epoxy resin adhesive solution for flame-retardant copper clad laminates, characterized in that; It comprises the following raw materials in parts by weight: 60 - 80 parts of bisphenol A epoxy resin, 30 - 40 parts of benzoxazine resin, 10 - 20 parts of inorganic filler, 3 - 10 parts of flame retardant, 15 - 25 parts of diluent, 5 - 10 parts of curing agent, and 0.5 - 1.5 parts of accelerator.

2. The epoxy resin adhesive solution for flame-retardant copper clad laminate according to claim 1, wherein: It comprises the following raw materials in parts by weight: 65 - 75 parts of bisphenol A epoxy resin, 33 - 37 parts of benzoxazine resin, 13 - 17 parts of inorganic filler, 5 - 7 parts of flame retardant, 18 - 22 parts of diluent, 6 - 8 parts of curing agent, and 0.8 - 1.2 parts of accelerator.

3. The epoxy resin adhesive solution for flame-retardant copper clad laminate according to claim 1, characterized in that: It comprises the following raw materials in parts by weight: 70 parts of bisphenol A epoxy resin, 35 parts of benzoxazine resin, 15 parts of inorganic filler, 6 parts of flame retardant, 20 parts of diluent, 7 parts of curing agent, and 1 part of accelerator.

4. The epoxy resin adhesive solution for flame-retardant copper clad laminate according to claim 1, characterized in that: The inorganic filler is a mixture of modified magnesium hydroxide and modified barium sulfate, and the weight ratio of the modified magnesium hydroxide to the modified barium sulfate is 1:(0.3 - 1.2). The diluent is a mixture of acetone and polypropylene glycol diglycidyl ether, and the mass ratio of the acetone to the polypropylene glycol diglycidyl ether is 1:(1 - 1.5). The curing agent is 2 - methylimidazole, and the accelerator is DMP - 30.

5. An epoxy resin adhesive solution for a flame-retardant copper clad laminate according to claim 4, characterized in that: The preparation method of the modified magnesium hydroxide and the modified barium sulfate is as follows: Add DMF solution to the weighed magnesium hydroxide and barium sulfate, heat and stir evenly, then add sodium oleate and sodium undecylenate, and stir at a constant temperature for 2 - 4 h under ultrasonic assistance. After the reaction is completed, evaporate and concentrate, filter, wash, and dry to obtain the modified magnesium hydroxide and the modified barium sulfate.

6. The epoxy resin adhesive solution for flame-retardant copper clad laminate according to claim 5, characterized in that: The addition amounts of the sodium oleate and the sodium undecylenate are respectively (0.2 - 0.4) and (0.1 - 0.3) of the sum of the masses of the modified magnesium hydroxide and the modified barium sulfate. The frequency during ultrasonic assistance is 90 - 120 KHz, and the temperature during constant - temperature stirring is 70 - 80 °C.

7. An epoxy resin adhesive solution for a flame-retardant copper clad laminate according to claim 1, characterized in that: The preparation method of the flame retardant is as follows: Weigh 50 - 100 parts of pentaerythritol, add it to 300 - 600 parts of water and stir to dissolve, then add 100 - 200 parts of melamine and 20 - 80 parts of sodium hydroxide solution and heat to dissolve. After heating to 80 - 100 °C, add 120 - 260 parts of cyanuric acid, 30 - 60 parts of zinc sulfate, 30 - 60 parts of zinc oxide, and 40 - 80 parts of montmorillonite solution in sequence. Keep stirring and reacting at a constant temperature for 1 - 2 h, then add 10 - 30 parts of borax solution, continue to react for 2 - 3 h to obtain a white viscous product, and obtain the flame retardant after suction filtration, washing, drying, and pulverizing.

8. An epoxy resin adhesive solution for a flame-retardant copper clad laminate according to claim 7, characterized in that: The preparation method of the montmorillonite solution is as follows: Add 5000 ml of ethanol to 50 g of montmorillonite, stir and react at 60 - 80 °C for 3 - 6 h, and the ethanol evaporates and refluxes during the heating reaction process.

9. The processing technology of an epoxy resin adhesive solution for a flame-retardant copper clad laminate according to any one of claims 1-8, characterized in that: Specifically, it includes the following steps: Step 1: Weigh the raw materials according to the above parts by weight, mix the weighed bisphenol A epoxy resin, benzoxazine resin, and diluent evenly, and then add the flame retardant and the inorganic filler at 80 - 90 °C to obtain a premix. Step 2: Add the curing agent and the accelerator to the premix and mix evenly to obtain the epoxy resin adhesive for flame - retardant copper - clad laminate.

10. Use of an epoxy resin adhesive solution for a flame-retardant copper clad laminate according to claims 1-8, characterized in that: It includes the following steps: Spray the epoxy resin glue solution on the surface of the flame-retardant copper clad laminate, cure it at 80-100 °C, and after complete curing for 1-3 h, perform grinding and cleaning to form a cured layer.

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