A halogen-free copper clad laminate substrate material containing flame-retardant modified benzoxazine resin and a preparation method thereof

Abstract

The present invention relates to the technical field of benzoxazine resins, and discloses a halogen-free copper clad laminate substrate material containing a flame-retardant modified benzoxazine resin and a preparation method thereof. In the present invention, 1,2,4,5-benzenetetramine is subjected to an acyl chlorination reaction with phosphorus oxychloride to obtain an intermediate product 1, and then it is subjected to a substitution reaction with p-hydroxybenzaldehyde to obtain an intermediate product 2. The aldehyde group contained therein is used to carry out a Schiff base reaction with 3-aminophenoxyphthalonitrile to obtain an intermediate product 3. Under the catalytic reduction of Raney nickel, a phosphorus-containing polyamine is obtained. Finally, it is subjected to a Mannich reaction with bisphenol A and paraformaldehyde to obtain a flame-retardant modified hyperbranched benzoxazine resin. Finally, it is stirred and mixed evenly with E-51 epoxy resin, N,N-dimethylbenzylamine, etc., coated on a glass fiber cloth, and cured to obtain a halogen-free copper clad laminate substrate material containing a flame-retardant modified benzoxazine resin. The halogen-free copper clad laminate substrate material prepared by the present invention has good flame retardancy, thermal stability and mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of benzoxazine resins, and specifically to a halogen-free copper clad laminate substrate material containing flame-retardant modified benzoxazine resin and a preparation method thereof. Background Art

[0002] Copper clad laminates are basic materials for electronic products, which are made by impregnating reinforcing materials with resin impregnating adhesives and covering with copper foil through hot pressing. The research on the flame retardancy of copper clad laminates, which are indispensable for electronic products, is also crucial. The flame retardant modification of copper clad laminates usually involves adding flame-retardant halogens to the resin matrix. However, halogen-containing compounds as flame retardants are likely to cause environmental pollution and endanger people's physical health. Therefore, the development of a halogen-free copper clad laminate substrate material has become a research hotspot.

[0003] Epoxy resins are widely used in the fields of packaging materials such as semiconductors, integrated circuits, and copper clad laminates. The limiting oxygen index of ordinary epoxy resins is only about 19.5, belonging to flammable substances. Therefore, the copper clad laminate substrate materials prepared from them have potential dangers. How to improve the flame retardancy of epoxy resins to better meet the increasingly extensive technical development needs has attracted the wide attention of researchers at home and abroad. Benzoxazine is a novel resin based on traditional phenolic resins, which is prepared from phenolic compounds, paraformaldehyde, and amine compounds, and has good heat resistance, flame retardancy, dielectric properties, and mechanical properties.

[0004] For example, the patent with the application publication number CN 103214794 A discloses a halogen-free epoxy resin composition for copper clad laminates and its application. The invention uses epoxy resin, benzoxazine, phenolic resin, etc. as raw materials, and the prepared composition has characteristics such as high heat resistance, low water absorption, good toughness, and good adhesion. However, it does not improve the flame retardant performance of the composition material. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] Aiming at the deficiencies of the prior art, the present invention provides a halogen-free copper clad laminate substrate material containing flame-retardant modified benzoxazine resin and a preparation method thereof. The prepared halogen-free copper clad laminate substrate material has good flame retardant performance and mechanical properties.

[0007] (II) Technical Solutions

[0008] A halogen-free copper clad laminate substrate material containing flame-retardant modified benzoxazine resin, and the halogen-free copper clad laminate substrate material is composed of the following components in parts by weight: 100 parts by weight of E-51 epoxy resin, 20-50 parts by weight of flame-retardant modified hyperbranched benzoxazine resin, 30-40 parts by weight of N,N-dimethylformamide, 30-40 parts by weight of methanol, 0.5-1 part by weight of N,N-dimethylbenzylamine, and 12-30 parts by weight of modified magnesium hydroxide;

[0009] The preparation method of the halogen-free copper clad laminate substrate material is as follows:

[0010] Stir and mix the E-51 epoxy resin, flame-retardant modified hyperbranched benzoxazine resin, N,N-dimethylformamide, and methanol evenly, add N,N-dimethylbenzylamine thereto, cure at 80-90 °C for 3-4 h, then add modified magnesium hydroxide thereto, stir and mix evenly, coat it on a glass fiber cloth, and carry out curing under a curing process of 140 °C / 3 h + 160 °C / 2 h + 180 °C / 3 h to obtain the halogen-free copper clad laminate substrate material containing flame-retardant modified benzoxazine resin.

[0011] Preferably, the preparation method of the flame-retardant modified hyperbranched benzoxazine resin is as follows:

[0012] (1) Add 1,2,4,5-benzenetetramine, dichloromethane, and dichloroethane to a flask, stir evenly, then add phosphorus oxychloride thereto, heat up to 45-55 °C, react for 3-6 h, after the reaction is completed, cool and filter, wash with acetonitrile, and dry to obtain intermediate product 1;

[0013] (2) Add intermediate product 1 and acetonitrile to a flask, stir and mix evenly at 60-70 °C, introduce nitrogen, add p-hydroxybenzaldehyde and triethylamine thereto, react at 80 °C for 4-6 h, after the reaction is completed, add a 1% sodium hydroxide aqueous solution thereto, stir for 20-30 min, wash successively with ice water and ether, and dry to obtain intermediate product 2;

[0014] (3) Add intermediate product 2 and 3-aminophenoxyphthalonitrile to a flask, add ethanol thereto, stir and mix evenly, then add glacial acetic acid thereto, stir and react at 55-65 °C for 5-8 h, after the reaction is completed, cool to room temperature, filter, wash with ethanol, and dry to obtain intermediate product 3;

[0015] (4) Add intermediate product 3 and ethanol to an autoclave, then add 30% ammonia water by mass fraction and Raney nickel thereto, react under a hydrogen pressure of 0.01 MPa for 2-5 h, after the reaction is completed, filter, and carry out vacuum distillation and dehydration on the filtrate, and dry to obtain a phosphorus-containing polyamine;

[0016] (5) At room temperature, bisphenol A, phosphorus-containing polyamine, and paraformaldehyde are dissolved in an ethanol solution, and the temperature is raised to 70 - 85 °C. The reaction is carried out for 8 - 12 h. After the reaction is completed, it is cooled to room temperature, filtered, washed successively with 5% sodium bicarbonate and deionized water, and dried to obtain a flame-retardant modified hyperbranched benzoxazine resin.

[0017] Further preferably, in the above (1), the molar ratio of 1,2,4,5-benzenetetramine to phosphorus oxychloride is 1:2 - 2.5, and the volume ratio of dichloromethane to dichloroethane is 1:1.

[0018] Further preferably, in the above (2), the molar ratio of intermediate 1, p-hydroxybenzaldehyde, and triethylamine is 1:2 - 2.5:4 - 6.

[0019] Further preferably, in the above (3), the molar ratio of intermediate 2 to 3-aminophenoxyphthalonitrile is 1:2 - 2.6.

[0020] Further preferably, in the above (4), the molar ratio of intermediate 3 to Raney nickel is 1:12 - 16.

[0021] Further preferably, in the above (5), the molar ratio of bisphenol A, phosphorus-containing polyamine, and paraformaldehyde is 1:0.5 - 0.8:4 - 6.

[0022] (III) Beneficial technical effects

[0023] By preparing a flame-retardant modified hyperbranched benzoxazine resin, the present invention has a relatively large number of branched-chain structures. When it is introduced into epoxy resin, a three-dimensional cross-linked network structure is formed by using the relatively large number of branched-chain structures contained therein. This cross-linked network contains a relatively large number of polar groups, which can form hydrogen bonds with other polar groups in the substrate to form a relatively large number of cross-linking sites, compensating for the poor mechanical properties of epoxy resin, and synergistically improving the mechanical properties of the copper clad laminate substrate material with modified magnesium hydroxide. In addition, when the material is heated, the benzoxazine structure contained therein can open the ring to generate hydroxyl groups, which can catalyze the opening of the epoxy ring in epoxy resin and generate more effective cross-linking with epoxy resin, increasing the cross-linking density and improving the thermal stability and mechanical properties. The Schiff base structure, due to the C=N functional group in its molecular structure, can undergo a self-cross-linking reaction at high temperature to form a stable nitrogen-containing six-membered ring, endowing the material with excellent char-forming properties and further improving the mechanical properties and thermal stability of the material.

[0024] In addition, the hyperbranched benzoxazine resin prepared by the present invention contains a phosphorus-containing structure, which serves as an acid source, a large number of benzene ring structures, which serve as a carbon source, and a nitrogen-containing structure, which serves as a gas source. The three work together to enhance the flame retardancy of the material. In addition, the modified magnesium hydroxide has organic groups attached to its surface, which can be well wetted and dispersed in the substrate. Since magnesium hydroxide is a good inorganic flame retardant, an organic-inorganic synergistic flame retardant structure is formed, jointly enhancing the flame retardancy of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the reaction route of the phosphorus-containing polyamine. DETAILED DESCRIPTION OF THE INVENTION

[0026] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with the drawings and specific embodiments.

[0027] Preparation method of 3-aminophenoxyphthalonitrile: Dissolve 4-nitrophthalonitrile and 3-aminophenol in dimethyl sulfoxide solvent, add potassium carbonate thereto, and react at 80 °C for 10 h under nitrogen protection. After the reaction, add it to 1 M sodium hydroxide solution, filter by suction, wash with deionized water, and dry to obtain 3-aminophenoxyphthalonitrile.

[0028] Preparation method of modified magnesium hydroxide: Add 10 g of magnesium hydroxide to 100 g of deionized water, stir and disperse, then add 0.8 g of stearic acid thereto, raise the temperature to 80 °C, stir and react for 5 h. After the reaction, wash with deionized water and dry to obtain modified magnesium hydroxide.

[0029] Prepare Example 1

[0030] (1) Under ice bath conditions, add 0.2 mol of 1,2,4,5-benzenetetramine, 50 mL of dichloromethane, and 50 mL of dichloroethane to a flask, stir evenly, then add 0.4 mol of phosphorus oxychloride thereto, raise the temperature to 50 °C, and react for 5 h. After the reaction, cool and filter, wash with acetonitrile, and dry to obtain Intermediate 1.

[0031] (2) Add 0.04 mol of Intermediate 1 and 100 mL of acetonitrile to a flask, stir and mix evenly at 65 °C, introduce nitrogen, add 0.1 mol of p-hydroxybenzaldehyde and 0.2 mol of triethylamine thereto, and react at 80 °C for 5 h. After the reaction, add 1% sodium hydroxide aqueous solution by mass fraction thereto, stir for 30 min, wash successively with ice water and ether, and dry to obtain Intermediate 2.

[0032] (3) Add 0.05 mol of intermediate 2 and 0.1 mol of 3-aminophenoxyphthalonitrile into a flask, add 200 mL of ethanol thereto, stir and mix evenly, then drop 5 drops of glacial acetic acid into it, react with stirring at 60 °C for 6 h. After the reaction is completed, cool to room temperature, filter, wash with ethanol, and dry to obtain intermediate 3.

[0033] (4) Add 0.02 mol of intermediate 3 and 200 mL of ethanol into an autoclave, then add 50 g of 30% ammonia water and 0.25 mol of Raney nickel thereto. React under a hydrogen pressure of 0.01 MPa for 4 h. After the reaction is completed, filter, concentrate and dehydrate the filtrate under reduced pressure, and dry to obtain a phosphorus-containing polyamine.

[0034] (5) At room temperature, dissolve 0.04 mol of bisphenol A, 0.025 mol of phosphorus-containing polyamine, and 0.2 mol of paraformaldehyde in 200 mL of ethanol solution, heat up to 70 °C, and react for 8 h. After the reaction is completed, cool to room temperature, filter, wash successively with 5% sodium bicarbonate and deionized water, and dry to obtain a flame-retardant modified hyperbranched benzoxazine resin.

[0035] (6) Stir and mix 100 g of E-51 epoxy resin, 20 g of flame-retardant modified hyperbranched benzoxazine resin, 35 g of N,N-dimethylformamide, and 40 g of methanol evenly, then add 0.5 g of N,N-dimethylbenzylamine thereto, cure at 85 °C for 4 h, then add 12 g of modified magnesium hydroxide thereto, stir and mix evenly, coat it on a glass fiber cloth, and cure under a curing process of 140 °C / 3 h + 160 °C / 2 h + 180 °C / 3 h to obtain a halogen-free copper clad laminate substrate material containing a flame-retardant modified benzoxazine resin.

[0036] Preparation of Example 2

[0037] (1) Under ice bath conditions, add 0.2 mol of 1,2,4,5-benzenetetramine, 50 mL of dichloromethane, and 50 mL of dichloroethane into a flask, stir evenly, then add 0.5 mol of phosphorus oxychloride thereto, heat up to 55 °C, and react for 4 h. After the reaction is completed, cool and filter, wash with acetonitrile, and dry to obtain intermediate 1.

[0038] (2) Add 0.04 mol of intermediate 1 and 100 mL of acetonitrile into a flask, stir and mix evenly at 70 °C, introduce nitrogen, add 0.08 mol of p-hydroxybenzaldehyde and 0.24 mol of triethylamine thereto, react at 80 °C for 6 h. After the reaction is completed, add a 1% sodium hydroxide aqueous solution thereto, stir for 20 min, wash successively with ice water and ether, and dry to obtain intermediate 2.

[0039] (3) Add 0.05 mol of intermediate 2 and 0.12 mol of 3-aminophenoxyphthalonitrile into a flask, add 200 mL of ethanol thereto, stir and mix evenly, then drop 4 drops of glacial acetic acid into it, react with stirring at 65 °C for 6 h. After the reaction is completed, cool to room temperature, filter, wash with ethanol, and dry to obtain intermediate 3.

[0040] (4) Add 0.02 mol of intermediate 3 and 200 mL of ethanol into an autoclave, then add 50 g of 30% ammonia water by mass and 0.3 mol of Raney nickel thereto. React under a hydrogen pressure of 0.01 MPa for 4 h. After the reaction is completed, filter, distill off the solvent and dehydrate the filtrate under reduced pressure, and dry to obtain a phosphorus-containing polyamine.

[0041] (5) At room temperature, dissolve 0.04 mol of bisphenol A, 0.032 mol of phosphorus-containing polyamine, and 0.16 mol of paraformaldehyde in 200 mL of ethanol solution, heat up to 75 °C, and react for 10 h. After the reaction is completed, cool to room temperature, filter, wash successively with 5% sodium bicarbonate and deionized water, and dry to obtain a flame-retardant modified hyperbranched benzoxazine resin.

[0042] (6) Stir and mix 100 g of E-51 epoxy resin, 25 g of flame-retardant modified hyperbranched benzoxazine resin, 30 g of N,N-dimethylformamide, and 30 g of methanol evenly, then add 0.6 g of N,N-dimethylbenzylamine thereto, cure at 80 °C for 4 h, then add 15 g of modified magnesium hydroxide thereto, stir and mix evenly, coat it on a glass fiber cloth, and cure under a curing process of 140 °C / 3 h + 160 °C / 2 h + 180 °C / 3 h to obtain a halogen-free copper clad laminate substrate material containing a flame-retardant modified benzoxazine resin.

[0043] Preparation of Example 3

[0044] (1) Under ice bath conditions, add 0.2 mol of 1,2,4,5-benzenetetramine, 50 mL of dichloromethane, and 50 mL of dichloroethane into a flask, stir evenly, then add 0.45 mol of phosphorus oxychloride thereto, heat up to 45 °C, and react for 6 h. After the reaction is completed, cool and filter, wash with acetonitrile, and dry to obtain intermediate 1.

[0045] (2) Add 0.04 mol of intermediate 1 and 100 mL of acetonitrile into a flask, stir and mix evenly at 60 °C, introduce nitrogen, add 0.09 mol of p-hydroxybenzaldehyde and 0.16 mol of triethylamine thereto, react at 80 °C for 4 h. After the reaction is completed, add a 1% sodium hydroxide aqueous solution by mass thereto, stir for 25 min, wash successively with ice water and ether, and dry to obtain intermediate 2.

[0046] (3) Add 0.05 mol of intermediate 2 and 0.1 mol of 3-aminophenoxyphthalonitrile into a flask, add 200 mL of ethanol thereto, stir and mix evenly, then drop 5 drops of glacial acetic acid into it, react with stirring at 60 °C for 6 h. After the reaction is completed, cool to room temperature, filter, wash with ethanol, and dry to obtain intermediate 3.

[0047] (4) Add 0.02 mol of intermediate 3 and 200 mL of ethanol into an autoclave, then add 50 g of 30% ammonia water by mass and 0.32 mol of Raney nickel thereto, react under a hydrogen pressure of 0.01 MPa for 5 h. After the reaction is completed, filter, concentrate and dehydrate the filtrate under reduced pressure, and dry to obtain a phosphorus-containing polyamine.

[0048] (5) At room temperature, dissolve 0.04 mol of bisphenol A, 0.02 mol of phosphorus-containing polyamine, and 0.24 mol of paraformaldehyde in 200 mL of ethanol solution, heat up to 85 °C, and react for 12 h. After the reaction is completed, cool to room temperature, filter, wash successively with 5% sodium bicarbonate and deionized water, and dry to obtain a flame-retardant modified hyperbranched benzoxazine resin.

[0049] (6) Stir and mix 100 g of E-51 epoxy resin, 35 g of flame-retardant modified hyperbranched benzoxazine resin, 40 g of N,N-dimethylformamide, and 35 g of methanol evenly, then add 1 g of N,N-dimethylbenzylamine thereto, cure at 90 °C for 3 h, then add 20 g of modified magnesium hydroxide thereto, stir and mix evenly, coat it on a glass fiber cloth, and cure under a curing process of 140 °C / 3 h + 160 °C / 2 h + 180 °C / 3 h to obtain a halogen-free copper clad laminate substrate material containing a flame-retardant modified benzoxazine resin.

[0050] Preparation of Example 4

[0051] (1) Under ice bath conditions, add 0.2 mol of 1,2,4,5-benzenetetramine, 50 mL of dichloromethane, and 50 mL of dichloroethane into a flask, stir evenly, then add 0.42 mol of phosphorus oxychloride thereto, heat up to 50 °C, and react for 3 h. After the reaction is completed, cool and filter, wash with acetonitrile, and dry to obtain intermediate 1.

[0052] (2) Add 0.04 mol of intermediate 1 and 100 mL of acetonitrile to a flask, stir and mix evenly at 65 °C, introduce nitrogen, add 0.09 mol of p-hydroxybenzaldehyde and 0.2 mol of triethylamine thereto, react at 80 °C for 5 h. After the reaction is completed, add an aqueous sodium hydroxide solution with a mass fraction of 1% thereto, stir for 25 min, wash successively with ice water and ether, and dry to obtain intermediate 2.

[0053] (3) Add 0.05 mol of intermediate 2 and 0.12 mol of 3-aminophenoxyphthalonitrile to a flask, add 200 mL of ethanol thereto, stir and mix evenly, then add 3 drops of glacial acetic acid thereto, react at 65 °C with stirring for 5 h. After the reaction is completed, cool to room temperature, filter, wash with ethanol, and dry to obtain intermediate 3.

[0054] (4) Add 0.02 mol of intermediate 3 and 200 mL of ethanol to an autoclave, then add 50 g of aqueous ammonia with a mass fraction of 30% and 0.3 mol of Raney nickel thereto, react under a hydrogen pressure of 0.01 MPa for 2 h. After the reaction is completed, filter, concentrate and dehydrate the filtrate under reduced pressure, and dry to obtain a phosphorus-containing polyamine.

[0055] (5) At room temperature, dissolve 0.04 mol of bisphenol A, 0.02 mol of phosphorus-containing polyamine, and 0.2 mol of paraformaldehyde in 200 mL of ethanol solution, heat up to 75 °C, and react for 10 h. After the reaction is completed, cool to room temperature, filter, wash successively with 5% sodium bicarbonate and deionized water, and dry to obtain a flame-retardant modified hyperbranched benzoxazine resin.

[0056] (6) Stir and mix 100 g of E-51 epoxy resin, 40 g of flame-retardant modified hyperbranched benzoxazine resin, 35 g of N,N-dimethylformamide, and 40 g of methanol evenly, then add 0.8 g of N,N-dimethylbenzylamine thereto, cure at 85 °C for 4 h, then add 25 g of modified magnesium hydroxide thereto, stir and mix evenly, coat it on a glass fiber cloth, and cure under a curing process of 140 °C / 3 h + 160 °C / 2 h + 180 °C / 3 h to obtain a halogen-free copper clad laminate substrate material containing a flame-retardant modified benzoxazine resin.

[0057] Preparation of Example 5

[0058] (1) Under ice bath conditions, add 0.2 mol of 1,2,4,5-benzenetetramine, 50 mL of dichloromethane, and 50 mL of dichloroethane to a flask, stir evenly, then add 0.45 mol of phosphorus oxychloride thereto, heat up to 55 °C, and react for 5 h. After the reaction is completed, cool and filter, wash with acetonitrile, and dry to obtain intermediate 1.

[0059] (2) 0.04 mol of intermediate product 1 and 100 mL of acetonitrile were added to a flask, stirred and mixed evenly at 65 °C, nitrogen was introduced, 0.09 mol of p-hydroxybenzaldehyde and 0.22 mol of triethylamine were added thereto, and the reaction was carried out at 80 °C for 6 h. After the reaction was completed, an aqueous sodium hydroxide solution with a mass fraction of 1% was added thereto, stirred for 25 min, washed successively with ice water and ether, and dried to obtain intermediate product 2.

[0060] (3) 0.05 mol of intermediate product 2 and 0.13 mol of 3-aminophenoxyphthalonitrile were added to a flask, 200 mL of ethanol was added thereto, stirred and mixed evenly, 4 drops of glacial acetic acid were added dropwise thereto, and the reaction was carried out at 55 °C with stirring for 8 h. After the reaction was completed, it was cooled to room temperature, filtered, washed with ethanol, and dried to obtain intermediate product 3.

[0061] (4) 0.02 mol of intermediate product 3 and 200 mL of ethanol were added to an autoclave, 50 g of aqueous ammonia with a mass fraction of 30% and 0.24 mol of Raney nickel were added thereto, and the reaction was carried out under a hydrogen pressure of 0.01 MPa for 4 h. After the reaction was completed, it was filtered, the filtrate was concentrated under reduced pressure to remove the solvent and water, and dried to obtain a phosphorus-containing polyamine.

[0062] (5) At room temperature, 0.04 mol of bisphenol A, 0.03 mol of phosphorus-containing polyamine, and 0.2 mol of paraformaldehyde were dissolved in 200 mL of ethanol solution, heated to 75 °C, and the reaction was carried out for 12 h. After the reaction was completed, it was cooled to room temperature, filtered, washed successively with 5% sodium bicarbonate and deionized water, and dried to obtain a flame-retardant modified hyperbranched benzoxazine resin.

[0063] (6) 100 g of E-51 epoxy resin, 50 g of flame-retardant modified hyperbranched benzoxazine resin, 35 g of N,N-dimethylformamide, and 40 g of methanol were stirred and mixed evenly, 0.8 g of N,N-dimethylbenzylamine was added thereto, and the curing was carried out at 85 °C for 4 h. Then 30 g of modified magnesium hydroxide was added thereto, stirred and mixed evenly, coated on a glass fiber cloth, and cured under a curing process of 140 °C / 3 h + 160 °C / 2 h + 180 °C / 3 h to obtain a halogen-free copper clad laminate substrate material containing a flame-retardant modified benzoxazine resin.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Preparation Example 1 is that in step (6), it does not contain a flame-retardant modified hyperbranched benzoxazine resin.

[0066] The glass transition temperature of the material was tested using a thermal analyzer. Under a nitrogen atmosphere, the heating rate was 20 °C / min, and the temperature change range was 25 - 300 °C.

[0067] Table 1:

[0068]

[0069] As can be seen from the table, the copper clad laminate substrate material prepared by the present invention has good thermal stability.

[0070] Referring to GB / T2406-2008, using an oxygen index tester, the flame retardant performance of the material was tested.

[0071] Table 2:

[0072]

[0073] The higher the oxygen index, the higher the flame retardant performance. As can be seen from the table, the copper clad laminate substrate material prepared by the present invention has good flame retardant performance.

[0074] Referring to GB / T4722-2017, using an electronic universal testing machine, the mechanical properties of the material were tested.

[0075] Table 3:

[0076]

[0077] As can be seen from the table, the copper clad laminate substrate material prepared by the present invention has good mechanical properties, and the maximum flexural strength can reach 521.7 MPa.

[0078] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and shall all fall within the protection scope of the present invention.

Claims

1. A halogen-free copper-clad laminate substrate material containing a flame-retardant modified benzoxazine resin, characterized in that: The halogen-free copper clad laminate substrate material is composed of the following components in parts by weight: 100 parts by weight of E-51 epoxy resin, 20-50 parts by weight of flame retardant modified hyperbranched benzoxazine resin, 30-40 parts by weight of N,N-dimethylformamide, 30-40 parts by weight of methanol, 0.5-1 parts by weight of N,N-dimethylbenzylamine, and 12-30 parts by weight of modified magnesium hydroxide; The preparation method of the halogen-free copper clad laminate substrate material is as follows: E-51 epoxy resin, flame retardant modified hyperbranched benzoxazine resin, N,N-dimethylformamide and methanol are stirred and mixed uniformly, N,N-dimethylbenzylamine is added thereto, and the mixture is aged at 80-90°C for 3-4h, and then modified magnesium hydroxide is added thereto, and the mixture is stirred and mixed uniformly, and the mixture is coated on a glass fiber cloth, and cured under a curing process of 140°C / 3h+160°C / 2h+180°C / 3h to obtain a halogen-free copper clad laminate substrate material containing a flame retardant modified benzoxazine resin; The preparation method of the flame retardant modified hyperbranched benzoxazine resin is: (1) Add 1,2,4,5-benzenetetramine, dichloromethane and dichloroethane into a flask, stir evenly, then add phosphorus oxychloride, heat to 45-55° C., react for 3-6 hours, and after the reaction is completed, cool and filter, wash with acetonitrile, and dry to obtain intermediate 1; (2) Add the intermediate product 1 and acetonitrile to a flask, stir and mix at 60-70° C., introduce nitrogen, add p-hydroxybenzaldehyde and triethylamine, react at 80° C. for 4-6 hours, and after the reaction, add a 1% sodium hydroxide aqueous solution, stir for 20-30 minutes, wash with ice water and ether, and dry to obtain the intermediate product 2; (3) adding the intermediate product 2,3-aminophenoxyphthalonitrile to a flask, adding ethanol thereto, stirring and mixing evenly, then adding glacial acetic acid thereto, stirring and reacting at 55-65° C. for 5-8 hours, and after the reaction is completed, cooling to room temperature, filtering, washing with ethanol, and drying to obtain an intermediate product 3; (4) adding the intermediate product 3 and ethanol to a pressure autoclave, and then adding 30% by mass of ammonia water and Raney nickel thereto, reacting for 2-5 hours under a hydrogen pressure of 0.01 MPa. After the reaction is completed, filtering, desolventizing, dehydrating, and drying the filtrate to obtain a phosphorus-containing polyamine; (5) At room temperature, bisphenol A, phosphorus-containing polyamine and paraformaldehyde are dissolved in an ethanol solution, the temperature is raised to 70-85° C., and the reaction is performed for 8-12 hours. After the reaction is completed, the solution is cooled to room temperature, filtered, washed with 5% sodium bicarbonate and deionized water in turn, and dried to obtain a flame-retardant modified hyperbranched benzoxazine resin.

2. The halogen-free copper clad laminate substrate material containing flame retardant modified benzoxazine resin according to claim 1, characterized in that: In the above (1), the molar ratio of 1,2,4,5-benzenetetramine to phosphorus oxychloride is 1:2-2.

5.

3. The halogen-free copper clad laminate substrate material containing flame retardant modified benzoxazine resin according to claim 1, characterized in that: In the above (2), the molar ratio of the intermediate product 1, p-hydroxybenzaldehyde and triethylamine is 1:2-2.5:4-6.

4. The halogen-free copper clad laminate substrate material containing flame retardant modified benzoxazine resin according to claim 1, characterized in that: In the above (3), the molar ratio of the intermediate product 2, 3-aminophenoxyphthalonitrile is 1:2-2.

6.

5. The halogen-free copper clad laminate substrate material containing flame retardant modified benzoxazine resin according to claim 2, characterized in that: In the above (4), the molar ratio of the intermediate product 3 to Raney nickel is 1:12-16.

6. The halogen-free copper clad laminate substrate material containing flame retardant modified benzoxazine resin according to claim 1, characterized in that: In the above (5), the molar ratio of bisphenol A, phosphorus-containing polyamine and paraformaldehyde is 1:0.5-0.8:4-6.

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