High-performance flame-retardant low-dielectric-loss copper-clad plate and preparation method thereof

Abstract

The application relates to the field of copper-clad plates, and discloses a high-performance flame-retardant low-dielectric-loss copper-clad plate and a preparation method thereof.The copper-clad plate comprises epoxy resin, benzoxazine resin, composite filler, carboxyl-terminated nitrile rubber, active diluent, curing agent and the like; the composite filler is prepared by compounding graphene oxide grafted with a flame-retardant modifier and hollow-sphere silicon dioxide modified with an epoxy group silane; the flame-retardant modifier is prepared by using boric acid and pentaerythritol to prepare a boron-containing intermediate with two terminal hydroxyl groups, then using diphenyldichlorosilane and phenylphosphinic dichloride to react with the two terminal hydroxyl groups to prepare a flame-retardant intermediate, and using amino silane and vanillin to react with two terminal chlorine atoms respectively to prepare an aldehyde group modified flame-retardant intermediate, and finally integrating the aldehyde group modified flame-retardant intermediate into polyethylene imine through Schiff base reaction to prepare the composite filler; the copper-clad plate prepared by the application has low dielectric constant and dielectric loss, high thermal conductivity, good flexibility, excellent heat resistance and flame-retardant performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copper-clad plates, and particularly relates to a high-performance flame-retardant low-dielectric-loss copper-clad plate and a preparation method thereof. BACKGROUND

[0002] With the development of electronic information technology towards high frequency, high speed and high integration, the performance requirements of copper-clad plates are also higher and higher, which mainly manifest in dielectric constant, dielectric loss and thermal conductivity coefficient and the like. The ordinary copper-clad plate cannot meet the needs of high-end electronic products due to the defects of large dielectric constant, large dielectric loss and poor heat dissipation. The resin matrix as the main raw material for manufacturing the copper-clad plate can largely determine the performance of the copper-clad plate, and thus the use of a resin with more excellent performance can improve the performance of the printed circuit board (PCB) to a certain extent.

[0003] At present, the resins commonly used in the copper-clad plate include epoxy resin, polyimide resin, bismaleimide triazine resin, phenolic resin and the like. Among them, the epoxy resin has excellent comprehensive performance, has the advantages of high adhesive strength, low curing shrinkage, good dimensional stability and the like, has been widely used in various fields, has relatively low cost, can cope with various harsh environments and working conditions, meets the requirements of high strength, high reliability and durability, and has competitiveness in the field of copper-clad plates.

[0004] However, the cured epoxy resin also has the defects of brittle quality and poor high-temperature resistance, which limits its application range to a certain extent. In addition, the copper-clad plate as the substrate material of the printed circuit board (PCB) needs to have certain flame-retardant performance to meet the needs of electronic product applications. The conventional copper-clad plate is composed of resin, glass cloth and copper foil and the like, among which the glass cloth and the copper foil are non-flammable or difficult to burn, so the flame retardation of the copper-clad plate needs to be improved from the flame retardation of the resin. However, the epoxy resin is flammable, and the oxygen index is only about 22%, which greatly limits its application range. SUMMARY

[0005] To solve the problems mentioned in the background, the purpose of the present application is to provide a high-performance flame-retardant low-dielectric-loss copper-clad plate and a preparation method thereof. The epoxy resin and the benzoxazine resin are used as the base resin, and the composite filler is added, so that the prepared copper-clad plate has low dielectric constant and dielectric loss, high thermal conductivity coefficient, good flexibility, excellent heat resistance and flame retardation.

[0006] The purpose of the present application can be achieved by the following technical solutions.

[0007] The application discloses a high-performance flame-retardant low-dielectric-loss copper-clad plate, which comprises the following components in parts by weight: 60-75 parts of epoxy resin, 10-40 parts of benzoxazine resin, 5-10 parts of composite filler, 5-15 parts of carboxyl-terminated nitrile rubber, 10-20 parts of active diluent, 10-30 parts of curing agent, 2-4 parts of curing accelerator and 40-55 parts of organic solvent.

[0008] The composite filler is prepared by compounding modified graphene oxide and silica hollow spheres modified by 3-(2,3-epoxypropoxy) propyl trimethoxysilane; wherein the modified graphene oxide is prepared by grafting a flame-retardant modifier on the surface of graphene oxide through chemical reaction.

[0009] The flame-retardant modifier is prepared by the following steps: preparing a double-end hydroxyl boron-containing intermediate by using boric acid and pentaerythritol, preparing a flame-retardant intermediate by substituting the hydroxyl groups at two ends of the double-end hydroxyl boron-containing intermediate with diphenyldichlorosilane and phenylphosphonic dichloride, preparing an aldehyde group modified flame-retardant intermediate by substituting the chlorine atoms at two ends of the flame-retardant intermediate with 3-aminopropyl trimethoxysilane and vanillin respectively, and finally integrating the aldehyde group modified flame-retardant intermediate into a polyethyleneimine structure through a Schiff base reaction.

[0010] Preferably, the active diluent is AGE-748; the curing agent is one of isophorone diamine, 4,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl sulfone; the curing accelerator is one of 2-ethyl-4-methyl imidazole and 2-methyl imidazole; and the organic solvent is one or a combination of multiple of toluene, acetone, butanone, dimethylbenzene and N,N-dimethylformamide.

[0011] Preferably, the preparation method of the composite filler comprises the following steps:

[0012] A. dispersing graphene oxide in a mixed solution of anhydrous ethanol and deionized water under ultrasonic condition, then adding a flame-retardant modifier, stirring and reacting at 70-95 DEG C for 4-6 hours, and then filtering, washing and drying to prepare the modified graphene oxide;

[0013] B. dispersing silica hollow spheres in a mixed solution of deionized water and anhydrous ethanol under ultrasonic condition, adding 3-(2,3-epoxypropoxy) propyl trimethoxysilane, stirring and ultrasonicizing for 0.5-1 hour, then stirring in a water bath at 55-70 DEG C for 1-2 hours, and then centrifuging, washing and drying to prepare the modified silica hollow spheres;

[0014] C. dispersing the modified graphene oxide and the modified silica hollow spheres in a mixed solution of deionized water and anhydrous ethanol under ultrasonic condition, then refluxing in a water bath at 55-70 DEG C for 2-4 hours, and then centrifuging, washing and drying to prepare the composite filler.

[0015] Preferably, the preparation method of the hollow silica spheres comprises the following steps: taking hexadecyl trimethyl ammonium bromide, ethanol and deionized water to be stirred and mixed at 35-40℃ to obtain solution one, taking n-hexane and tetraethyl orthosilicate to be ultrasonically mixed uniformly to obtain solution two, dropping solution two into solution one, stirring for 0.5-1h, then adding ammonia water, stirring in a water bath at 35-40℃ for 2-3h, transferring to a reaction kettle after stirring is completed, hydrothermal treatment at 175-185℃ for 4-8h, finally centrifuging, washing, drying, and calcining the obtained product at 600-900℃ for 4-6h to prepare the hollow silica spheres.

[0016] Preferably, the preparation method of the flame-retardant modifier in step A comprises the following steps:

[0017] (1) taking boric acid and pentaerythritol in a reactor, adding toluene solvent, connecting an oil-water separator with a spherical condenser, reacting at 105-115℃ until no water is generated in the oil-water separator, then continuing to heat until toluene is completely evaporated, after reaction is completed, recrystallizing with acetone and drying to prepare a double-end hydroxyl boron-containing intermediate;

[0018] (2) taking diphenyldichlorosilane, phenyl phosphinic dichloride and the double-end hydroxyl boron-containing intermediate in a reactor, adding tetrahydrofuran solvent, stirring and reacting at 60-85℃ for 4-7h, adding triethylamine in batches during the reaction, after reaction is completed, filtering, rotary evaporation and drying to prepare a flame-retardant intermediate;

[0019] (3) taking the flame-retardant intermediate and triethylamine in a reactor, adding tetrahydrofuran solvent, heating to 40-55℃, dissolving 3-aminopropyl trimethoxysilane in tetrahydrofuran and dropping into the reactor, stirring and reacting for 8-10h, after reaction is completed, filtering, washing and drying to prepare a modified flame-retardant intermediate;

[0020] (4) dissolving vanillin in tetrahydrofuran, adding triethylamine, then adding a mixed solution of the modified flame-retardant intermediate and tetrahydrofuran solution, stirring and reacting at 55-70℃ for 10-12h, after reaction is completed, filtering and rotary evaporation to prepare an aldehyde-modified flame-retardant intermediate;

[0021] (5) taking polyethyleneimine in a reactor, dissolving in methanol, heating to 75-85℃, adding a mixed solution of the aldehyde-modified flame-retardant intermediate and methanol under a nitrogen atmosphere, stirring and reacting for 10-12h, after reaction is completed, removing the organic solvent by rotary evaporation to prepare the flame-retardant modifier.

[0022] Preferably, the molar ratio of boric acid to pentaerythritol in step (1) is 2-2.2:1.

[0023] Preferably, the structure formula of the flame-retardant intermediate in the step (2) is: ;

[0024] The molar ratio of the diphenyl dichlorosilane, phenyl phosphinic dichloride and the double-end hydroxyl boron-containing intermediate is 1~1.1:1:1~1.1.

[0025] Preferably, the molar ratio of the flame-retardant intermediate and 3-aminopropyl trimethoxysilane in the step (3) is 1:1~1.3.

[0026] Preferably, the structure formula of the aldehyde group modified flame-retardant intermediate in the step (4) is: ;

[0027] The molar ratio of the vanillin and the modified flame-retardant intermediate is 1~1.3:1.

[0028] A preparation method of a high-performance flame-retardant low-dielectric-loss copper-clad plate, comprising the following steps:

[0029] S1, each component is weighed by weight parts, epoxy resin, benzoxazine resin, composite filler, active diluent, curing agent, curing accelerator and organic solvent are mixed to obtain a resin glue solution;

[0030] S2, the resin glue solution is uniformly coated on the PET release film, and is heated in a 120~150℃ oven for 6~10min to prepare a prepreg;

[0031] S3, the prepreg is taken and laminated, and a copper foil is coated on each side of the prepreg, and the high-performance flame-retardant low-dielectric-loss copper-clad plate is prepared through rolling and hot pressing processes.

[0032] The beneficial effects of the present application are:

[0033] The present application utilizes boric acid and pentaerythritol to prepare a double-end hydroxyl boron-containing intermediate, then one end of the chlorine atom in the structure of diphenyl dichlorosilane and phenyl phosphinic dichloride is substituted with the hydroxyl group at both ends of the double-end hydroxyl boron-containing intermediate to prepare a flame-retardant intermediate, and the amino group in the structure of 3-aminopropyl trimethoxysilane is substituted with one end of the chlorine atom in the structure of the flame-retardant intermediate to prepare a modified flame-retardant intermediate, then the hydroxyl group in the structure of vanillin is substituted with the remaining one end of the chlorine atom in the structure of the modified flame-retardant intermediate to prepare an aldehyde group modified flame-retardant intermediate, and finally the aldehyde group modified flame-retardant intermediate is integrated into the structure of polyethyleneimine through Schiff base reaction to prepare a new type of B, P, Si, N synergistic high-efficiency flame-retardant modifier, and the formed Schiff base structure has excellent crosslinking and carbonization properties at high temperature, which can further improve the flame-retardant performance of the material.

[0034] The present application utilizes the condensation reaction between the silicon hydroxyl in the structure of the flame-retardant modifier and the oxygen-containing group in the structure of graphene oxide to prepare modified graphene oxide, and then the modified graphene oxide is compounded with silica hollow spheres modified by 3-(2,3-epoxypropoxy) propyl trimethoxysilane, wherein the silica hollow spheres have a hollow structure and can introduce a proper amount of air into the resin matrix to reduce the dielectric property, the ungrafted carboxyl and hydroxyl groups on the surface of the modified graphene oxide produce a strong action through hydrogen bonds between the hydroxyl groups on the surface of the modified silica hollow spheres, the modified silica hollow spheres are attached to the surface of the modified graphene oxide, which is beneficial to the formation of a heat conduction channel and improves the thermal conductivity of the material, the composite filler formed by the two is beneficial to the dispersion of the composite filler in the resin matrix, the surface of the composite filler is rough, which is beneficial to the formation of more interfaces with the resin matrix and the enhancement of the interface action, thereby increasing the volume of the polar group and the steric hindrance, resulting in a reduction in the dielectric constant, when an external force acts on the resin matrix, a significant stress transfer phenomenon occurs in the resin matrix, and a large amount of energy in the crack can be effectively diffused, absorbed and consumed during diffusion, thereby enhancing the toughness of the resin matrix, since the oxygen-containing functional groups on the surface of the graphene oxide are reduced and there is a strong interface action between the composite filler and the epoxy resin, the movement of the epoxy resin segment is inhibited, and relaxation and orientation are more difficult, so the dielectric loss is reduced, and the reaction between the oxygen-containing functional groups of the graphene oxide and the epoxy resin or the curing agent is avoided, which affects the formation of the network structure during the curing process of the epoxy resin, thereby helping to improve the thermal stability of the matrix. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] The dicyclopentadiene type phenolic epoxy resin (DEN260) in the embodiments and comparative examples of the present application is produced by Changchun Artificial Resin Factory Co., Ltd.; the diamine type benzoxazine resin (TJ-7960) is produced by Guangzhou Taiji New Material Co., Ltd.; and the carboxyl-terminated butyl nitrile rubber (N21) is produced by Shanghai Lishenghang International Trade Co., Ltd.

[0037] The preparation method of the flame-retardant modifier in Example 1 comprises the following steps:

[0038] (1) Take 6.8 g of boric acid and 6.8 g of pentaerythritol in a reactor, add 40 mL of toluene solvent, connect the oil-water separator with the spherical condenser, and place it at 110°C until no water is produced in the oil-water separator, then continue to heat until the toluene is completely evaporated, after the reaction is completed, recrystallize with acetone and dry to prepare a double-end hydroxyl boron-containing intermediate;

[0039] (2) Take 2.6 g of diphenyldichlorosilane, 2.1 g of phenylphosphonic dichloride and 1.9 g of double-end hydroxyl boron-containing intermediate (Mr=187.7) in a reactor, add 100 mL of tetrahydrofuran solvent, stir at 80°C for 5h, add 2g of triethylamine in batches during the reaction, after the reaction is completed, filter, rotary evaporate, and dry to prepare a flame retardant intermediate;

[0040] (3) Take 5.6 g of flame retardant intermediate (Mr=562.9) and 1 g of triethylamine in a reactor, add 100 mL of tetrahydrofuran solvent, heat to 50°C, dissolve 1.8 g of 3-aminopropyltrimethoxysilane in 20 mL of tetrahydrofuran, and then add it to the reactor, stir for 10h, after the reaction is completed, filter, wash, and dry to prepare a modified flame retardant intermediate;

[0041] (4) Take 1.6 g of vanillin and dissolve it in 40 mL of tetrahydrofuran, add 1 g of triethylamine, then add 7.1 g of modified flame retardant intermediate (Mr=705.7) and 80 mL of tetrahydrofuran solution, stir at 60°C for 12h, after the reaction is completed, filter, rotary evaporate, and prepare an aldehyde-modified flame retardant intermediate;

[0042] (5) Take 6.1 g of polyethyleneimine in a reactor, add 70 mL of methanol to dissolve, heat to 80°C, add 8.2 g of aldehyde-modified flame retardant intermediate and 80 mL of methanol under nitrogen atmosphere, stir for 12h, after the reaction is completed, remove the organic solvent by rotary evaporation, and prepare a flame retardant modifier.

[0043] Example 2 A method for preparing a hollow silica sphere includes the following steps:

[0044] Take 0.08 g of cetyltrimethylammonium bromide, 50 mL of ethanol and 30 mL of deionized water, stir and mix at 40°C to obtain solution one, take 4 mL of n-hexane and 0.8 g of tetraethyl orthosilicate, ultrasonic mix uniformly to obtain solution two, drop solution two into solution one, stir for 1h, then add 0.5 mL of ammonia water, place in a 40°C water bath and stir for 2h, after stirring, transfer to a reaction kettle and hydrothermal treatment at 180°C for 8h, finally centrifuge, wash, dry, place the obtained product in a calciner at 850°C and calcine for 5h to prepare a hollow silica sphere.

[0045] The preparation method of the composite filler in Example 3 comprises the following steps:

[0046] A, 1g of graphene oxide was ultrasonically dispersed in a mixed solution of 100mL of anhydrous ethanol and 20mL of deionized water, then 1.4g of the flame retardant modifier prepared in Example 1 was added, and the mixture was stirred at 85℃ for 6h. After the reaction was completed, the modified graphene oxide was prepared by filtration, washing and drying;

[0047] B, 2g of the silica hollow sphere prepared in Example 2 was ultrasonically dispersed in a mixed solution of 20mL of deionized water and 100mL of anhydrous ethanol, 0.2g of 3-(2,3-epoxypropoxy) propyl trimethoxysilane was added, and the mixture was ultrasonically stirred for 1h, then placed in a water bath at 60℃ and stirred for 1h. After the reaction was completed, the modified silica hollow sphere was prepared by centrifugation, washing and drying;

[0048] C, 1g of the modified graphene oxide and 2g of the modified silica hollow sphere were ultrasonically dispersed in a mixed solution of 10mL of deionized water and 90mL of anhydrous ethanol, then placed in a water bath at 70℃ and refluxed for 4h. After the reaction was completed, the composite filler was prepared by centrifugation, washing and drying.

[0049] Example 4 A high-performance flame-retardant low-dielectric-loss copper-clad plate comprises the following components by weight:

[0050] 62 parts of dicyclopentadiene phenolic epoxy resin, 17 parts of diamine type benzoxazine resin, 5 parts of the composite filler prepared in Example 3, 5 parts of carboxyl-terminated butyl nitrile rubber, 12 parts of active diluent AGE-748, 10 parts of curing agent 4,4'-diaminodiphenyl methane, 2 parts of curing accelerator 2-methylimidazole, and 41 parts of organic solvent acetone.

[0051] The preparation method of the high-performance flame-retardant low-dielectric-loss copper-clad plate comprises the following steps:

[0052] S1, weigh each component according to the weight parts, mix the dicyclopentadiene phenolic epoxy resin, the diamine type benzoxazine resin, the composite filler, the active diluent, the curing agent, the curing accelerator and the organic solvent to obtain a resin glue solution;

[0053] S2, evenly coat the resin glue solution on the PET release film, place it in an oven at 145℃ for 8min to prepare a prepreg;

[0054] S3, take the prepreg and stack it with a copper foil on each side, then perform roll pressing and hot pressing processes at a temperature of 225℃ and a pressure of 4MPa for 1.5h to prepare the high-performance flame-retardant low-dielectric-loss copper-clad plate.

[0055] Example 5 A high-performance flame-retardant low-dielectric-loss copper-clad plate comprises the following components by weight:

[0056] Dicyclopentadiene phenolic epoxy resin 68 parts, diamine type benzoxazine resin 29 parts, composite filler prepared in Example 3 7 parts, carboxyl-terminated butyl nitrile rubber 10 parts, active diluent AGE-748 17 parts, curing agent 4,4'-oxydianiline 20 parts, curing accelerator 2-ethyl-4-methylimidazole 3 parts, organic solvent toluene 47 parts.

[0057] The preparation method of the high-performance flame-retardant low-dielectric loss copper-clad plate described above is the same as that of Example 4.

[0058] Example 6 A high-performance flame-retardant low-dielectric loss copper-clad plate comprises the following components by weight:

[0059] Dicyclopentadiene phenolic epoxy resin 72 parts, diamine type benzoxazine resin 35 parts, composite filler prepared in Example 3 9 parts, carboxyl-terminated butyl nitrile rubber 14 parts, active diluent AGE-748 20 parts, curing agent 4,4'-oxydianiline 28 parts, curing accelerator 2-ethyl-4-methylimidazole 4 parts, organic solvent toluene 47 parts.

[0060] The preparation method of the high-performance flame-retardant low-dielectric loss copper-clad plate described above is the same as that of Example 4.

[0061] Preparation method of a flame-retardant modifier in Comparative Example 1 comprises the following steps:

[0062] (1) Take 6.8 g of boric acid and 6.8 g of pentaerythritol in a reactor, add 40 mL of toluene solvent, connect the oil-water separator with the spherical condenser, and place it at 110°C until no water is generated in the oil-water separator, then continue to heat until the toluene is completely evaporated, after the reaction is completed, recrystallize and dry with acetone to prepare a double-hydroxyl boron-containing intermediate;

[0063] (2) Take 2.6 g of diphenyldichlorosilane, 2.1 g of phenylphosphonic dichloride, and 1.9 g of the double-hydroxyl boron-containing intermediate (Mr=187.7) in a reactor, add 100 mL of tetrahydrofuran solvent, stir at 80°C for 5 h, and add 2 g of triethylamine in batches during the reaction, after the reaction is completed, filter, rotary evaporate, and dry to prepare a flame-retardant intermediate;

[0064] (3) Take 5.6 g of the flame-retardant intermediate (Mr=562.9) and 1 g of triethylamine in a reactor, add 100 mL of tetrahydrofuran solvent, heat to 50°C, dissolve 1.8 g of 3-aminopropyltrimethoxysilane in 20 mL of tetrahydrofuran, and add it dropwise to the reactor, stir for 10 h, and after the reaction is completed, filter, wash, and dry to prepare a flame-retardant modifier.

[0065] Preparation method of a composite filler in Comparative Example 2 comprises the following steps:

[0066] A, 1 g of graphene oxide was ultrasonically dispersed in a mixed solution of 100 mL of anhydrous ethanol and 20 mL of deionized water, then 1.4 g of the flame retardant modifier prepared in Comparative Example 1 was added, and the mixture was stirred at 85°C for 6 h. After the reaction was completed, the modified graphene oxide was prepared by filtration, washing and drying;

[0067] B, 2 g of the silica hollow sphere prepared in Example 2 was ultrasonically dispersed in a mixed solution of 100 mL of deionized water and 20 mL of anhydrous ethanol, 0.2 g of 3-(2,3-epoxypropoxy) propyl trimethoxysilane was added, and the mixture was ultrasonically stirred for 1 h, then stirred in a water bath at 60°C for 1 h. After the reaction was completed, the modified silica hollow sphere was prepared by centrifugation, washing and drying;

[0068] C, 1 g of the modified graphene oxide and 2 g of the modified silica hollow sphere were ultrasonically dispersed in a mixed solution of 10 mL of deionized water and 90 mL of anhydrous ethanol, then the mixture was refluxed in a water bath at 70°C for 4 h. After the reaction was completed, the composite filler was prepared by centrifugation, washing and drying.

[0069] Comparative Example 3 A high-performance flame-retardant low-dielectric-loss copper-clad plate, comprising the following components by weight:

[0070] dicyclopentadiene phenolic epoxy resin 62 parts, diamine type benzoxazine resin 17 parts, composite filler prepared in Comparative Example 2 5 parts, carboxyl-terminated butyl nitrile rubber 5 parts, active diluent AGE-748 12 parts, curing agent 4,4'-diaminodiphenylmethane 10 parts, curing accelerator 2-methylimidazole 2 parts, organic solvent acetone 41 parts.

[0071] The preparation method of the above high-performance flame-retardant low-dielectric-loss copper-clad plate is the same as that of Example 4.

[0072] Comparative Example 4 A high-performance flame-retardant low-dielectric-loss copper-clad plate, comprising the following components by weight:

[0073] dicyclopentadiene phenolic epoxy resin 62 parts, diamine type benzoxazine resin 17 parts, modified graphene oxide prepared in Example 3 5 parts, carboxyl-terminated butyl nitrile rubber 5 parts, active diluent AGE-748 12 parts, curing agent 4,4'-diaminodiphenylmethane 10 parts, curing accelerator 2-methylimidazole 2 parts, organic solvent acetone 41 parts.

[0074] The preparation method of the above high-performance flame-retardant low-dielectric-loss copper-clad plate is the same as that of Example 4.

[0075] Comparative Example 5 A high-performance flame-retardant low-dielectric-loss copper-clad plate, comprising the following components by weight:

[0076] Dicyclopentadiene phenolic epoxy resin 62 parts, diamine type benzoxazine resin 17 parts, graphene oxide 2 parts, hollow silica sphere 3 parts, carboxyl-terminated butylnitrile rubber 5 parts, active diluent AGE-748 12 parts, curing agent 4,4'-diaminodiphenyl methane 10 parts, curing accelerator 2-methylimidazole 2 parts, organic solvent acetone 41 parts.

[0077] The preparation method of the high-performance flame-retardant low-dielectric loss copper-clad plate is the same as that in Embodiment 4.

[0078] Performance detection

[0079] The copper-clad plates prepared in Embodiments 4-6 and Comparative Examples 3-5 are subjected to performance detection: the thermal conductivity of the sample is tested by using a DRL-III thermal conductivity tester according to the ASTM D5470 standard; the dielectric constant and dielectric loss of the sample are tested by using a microwave network analyzer according to the IPC TM-650 2.5.5.13 standard, and the test frequency is 10 GHz; the heat resistance of the sample is tested by using a thermal gravimetric analyzer, and the whole test process is carried out under the protection of nitrogen, and the temperature is raised at a rate of 10 ℃ / min, and the temperature is 30-800 ℃; the bending strength of the sample is determined by using an electronic universal testing machine; the vertical burning performance test is carried out according to the UL94 standard (ASTM D3801), and the data results are shown in Table 1:

[0080]

[0081] As can be seen from the data in Table 1, the copper-clad plates prepared in Embodiments 4-5 have low dielectric constant and dielectric loss, high thermal conductivity, good flexibility, excellent heat resistance and flame-retardant performance. In Comparative Example 3, the flame-retardant modifier grafted on the composite filler does not introduce vanillin and polyethylene imine, and the measured heat resistance and flame-retardant performance are lower than those of Embodiments 4-5, because the structure of the composite filler does not introduce Schiff base groups and nitrogen elements, resulting in a decrease in flame-retardant performance, and the introduction of polyethylene imine can improve the heat resistance of the material to a certain extent. In Comparative Example 4, the composite filler is replaced with modified graphene oxide, and the measured dielectric constant and dielectric loss are higher than those of Embodiments 4-5, and the thermal conductivity, heat resistance and bending strength are lower than those of Embodiments 4-5, because the surface of the modified graphene oxide is not attached to modified hollow silica spheres. In Comparative Example 5, the graphene oxide and the hollow silica spheres are simply mixed, and the measured flame-retardant performance and bending strength are significantly lower than those of Embodiments 4-5, the dielectric constant and dielectric loss are slightly higher than those of Embodiments 4-5, and the thermal conductivity and heat resistance are slightly lower than those of Embodiments 4-5, because the graphene oxide and the hollow silica spheres are not modified and then combined.

[0082] In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate way in one or more embodiments or examples.

[0083] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A high-performance flame-retardant low-dielectric-loss copper-clad plate, characterized by, The composition comprises the following components by weight: 60-75 parts of epoxy resin, 10-40 parts of benzoxazine resin, 5-10 parts of composite filler, 5-15 parts of carboxyl-terminated nitrile rubber, 10-20 parts of active diluent, 10-30 parts of curing agent, 2-4 parts of curing accelerator, 40-55 parts of organic solvent; The composite filler is prepared by compounding modified graphene oxide and silica hollow spheres modified by 3-(2,3-epoxypropoxy) propyl trimethoxysilane; wherein the modified graphene oxide is prepared by grafting a flame-retardant modifier onto the surface of graphene oxide through chemical reaction; The flame-retardant modifier is prepared by using boric acid and pentaerythritol to prepare a double-end hydroxyl boron-containing intermediate, then using diphenyldichlorosilane and phenylphosphonic dichloride to substitute the hydroxyl groups at both ends of the double-end hydroxyl boron-containing intermediate to prepare a flame-retardant intermediate, and then using 3-aminopropyl trimethoxysilane and vanillin to substitute the chlorine atoms at both ends of the flame-retardant intermediate to prepare an aldehyde group modified flame-retardant intermediate, and finally integrating the aldehyde group modified flame-retardant intermediate into a polyethyleneimine structure through Schiff base reaction.

2. The high-performance flame-retardant low-dielectric-loss copper-clad plate according to claim 1, characterized in that, The active diluent is AGE-748; the curing agent is one of isophorone diamine, 4,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl sulfone; the curing accelerator is one of 2-ethyl-4-methyl imidazole and 2-methyl imidazole; and the organic solvent is one or a combination of toluene, acetone, butanone, dimethylbenzene and N,N-dimethylformamide.

3. The high-performance flame-retardant low-dielectric-loss copper-clad plate according to claim 1, characterized in that, The preparation method of the composite filler comprises the following steps: A, ultrasonic dispersion of graphene oxide in a mixed solution of anhydrous ethanol and deionized water, then adding a flame-retardant modifier, stirring at 70-95 DEG C for 4-6 hours, after the reaction is completed, filtering, washing and drying to prepare modified graphene oxide; B, ultrasonic dispersion of silica hollow spheres in a mixed solution of deionized water and anhydrous ethanol, adding 3-(2,3-epoxypropoxy) propyl trimethoxysilane, ultrasonic stirring for 0.5-1 hour, then stirring in a water bath at 55-70 DEG C for 1-2 hours, after the reaction is completed, centrifuging, washing and drying to prepare modified silica hollow spheres; C, ultrasonic dispersion of modified graphene oxide and modified silica hollow spheres in a mixed solution of deionized water and anhydrous ethanol, then refluxing in a water bath at 55-70 DEG C for 2-4 hours, after the reaction is completed, centrifuging, washing and drying to prepare the composite filler.

4. The high-performance flame-retardant low-dielectric-loss copper-clad plate according to claim 3, characterized in that, The preparation method of the silica hollow spheres comprises the following steps: mixing cetyltrimethylammonium bromide, ethanol and deionized water at 35-40 DEG C to obtain solution one, ultrasonic mixing of n-hexane and tetraethyl orthosilicate to obtain solution two, dropping solution two into solution one, stirring for 0.5-1 hour, then adding ammonia water, stirring in a water bath at 35-40 DEG C for 2-3 hours, after the stirring is completed, transferring to a reaction kettle for hydrothermal treatment at 175-185 DEG C for 4-8 hours, finally centrifuging, washing and drying, and calcining the obtained product at 600-900 DEG C for 4-6 hours to prepare silica hollow spheres.

5. The high-performance flame-retardant low-dielectric-loss copper-clad plate according to claim 3, characterized by, The preparation method of the flame-retardant modifier in step A comprises the following steps: (1) Take boric acid and pentaerythritol in a reactor, add toluene solvent, connect the oil-water separator with the spherical condenser, and react at 105-115 DEG C until no water is generated in the oil-water separator, then continue to heat until the toluene is completely evaporated, after the reaction is completed, recrystallize with acetone and dry to prepare a double-end hydroxyl boron-containing intermediate; (2) Take diphenyldichlorosilane, phenyl phosphinic dichloride and the double-end hydroxyl boron-containing intermediate in a reactor, add tetrahydrofuran solvent, stir and react at 60-85 DEG C for 4-7 h, add triethylamine in batches during the reaction, after the reaction is completed, filter, rotary evaporate and dry to prepare a flame-retardant intermediate; (3) Take the flame-retardant intermediate and triethylamine in a reactor, add tetrahydrofuran solvent, heat to 40-55 DEG C, add 3-aminopropyltrimethoxysilane dissolved in tetrahydrofuran dropwise into the reactor, stir and react for 8-10 h, after the reaction is completed, filter, wash and dry to prepare a modified flame-retardant intermediate; (4) Dissolve vanillin in tetrahydrofuran, add triethylamine, then add a mixed solution of the modified flame-retardant intermediate and tetrahydrofuran solution, stir and react at 55-70 DEG C for 10-12 h, after the reaction is completed, filter and rotary evaporate to prepare an aldehyde-modified flame-retardant intermediate; (5) Take polyethyleneimine in a reactor, add methanol to dissolve, heat to 75-85 DEG C, add a mixed solution of the aldehyde-modified flame-retardant intermediate and methanol under nitrogen atmosphere, stir and react for 10-12 h, after the reaction is completed, remove the organic solvent by rotary evaporation to prepare the flame-retardant modifier.

6. The high-performance flame-retardant low-dielectric-loss copper-clad plate according to claim 5, characterized by, The molar ratio of boric acid to pentaerythritol in step (1) is 2-2.2:

1.

7. The high-performance flame-retardant low-dielectric-loss copper-clad plate according to claim 5, characterized in that, The molar ratio of diphenyldichlorosilane, phenyl phosphinic dichloride and the double-end hydroxyl boron-containing intermediate in step (2) is 1-1.1:1:1-1.

1. 8.The high-performance flame-retardant low-dielectric-loss copper-clad plate of claim 5, characterized in that, The molar ratio of the flame-retardant intermediate to 3-aminopropyltrimethoxysilane in step (3) is 1:1-1.

3. 9.The high-performance flame-retardant low-dielectric-loss copper-clad plate of claim 5, characterized in that, The molar ratio of vanillin to the modified flame-retardant intermediate in step (4) is 1-1.3:

1.

10. A method for preparing the high-performance flame-retardant low-dielectric-loss copper-clad plate according to any one of claims 1-9, characterized in that, Comprise the following steps: S1, weigh each component by weight parts, mix epoxy resin, benzoxazine resin, composite filler, active diluent, curing agent, curing accelerator and organic solvent to obtain a resin glue solution; S2, uniformly coat the resin glue solution on the PET release film, heat in a 120-150 DEG C oven for 6-10 min to prepare a prepreg; S3, take the prepreg, stack, cover a copper foil on each side, and prepare a high-performance flame-retardant low-dielectric-loss copper-clad plate through rolling and hot pressing processes.

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