Trapezoidal phosphorus-containing polyborosiloxane flame retardant as well as preparation method and application thereof

Abstract

The invention discloses a trapezoidal phosphorus-containing polyborosiloxane flame retardant as well as a preparation method and application thereof, and belongs to the technical field of epoxy resin. The structural general formula of the flame retardant is shown in the following formula (I): # imgabs0 #, p and m are respectively and independently selected from integers between 1 and 20, and q and n are respectively and independently selected from integers between 1 and 6; r is selected from one or more of the group consisting of # imgabs1 # imgabs2 #. The trapezoidal phosphorus-containing polyborosiloxane flame retardant disclosed by the invention can obviously improve the flame retardant property of an epoxy resin cured product, improve the mechanical property and heat resistance of the epoxy resin cured product, reduce the maximum thermal decomposition rate of the resin cured product, and improve the carbon residue rate of the resin cured product at high temperature; wide application prospects are realized in the fields of adhesive materials, composite materials, copper-clad plate materials, electronic packaging materials and the like.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy resins, and in particular to a trapezoidal phosphorus-containing polyborosiloxane flame retardant and a preparation method and application thereof. Background Art

[0002] As a typical thermosetting resin, epoxy resin has attracted widespread attention due to its advantages such as good adhesion, low price, low shrinkage, good electrical insulation, and good process performance. However, the flammability of epoxy resin causes it to generate a large amount of heat and toxic gases during combustion, which can easily threaten people's life safety and property loss. Therefore, flame retardant modification of epoxy resin cured products is of great practical significance.

[0003] Halogen flame retardants are a traditional and efficient flame retardant. They produce a large amount of toxic gases during the flame retardant process, causing great pollution. Halogen-free flame retardants such as phosphorus, silicon, nitrogen, and boron have received widespread attention because they are green and environmentally friendly and have a certain flame retardant effect. However, when a single flame retardant element is used to flame retard epoxy resin, the amount of its addition is large, and it will affect other properties of the material and have a very limited improvement in the degree of flame retardancy. Therefore, through the coordinated construction of multiple flame retardant elements, efficient flame retardancy of epoxy resin can be achieved.

[0004] Polysiloxane is a polymer whose main chain is composed of silicon-oxygen bonds. It has excellent comprehensive properties, such as high thermal stability, excellent flexibility, excellent flame retardancy and strong hydrophobicity. It is an excellent modifier for epoxy resin. Polysiloxane with reactive functional groups (hydroxyl, carboxyl, amino, aliphatic epoxy) can participate in the curing of epoxy resin matrix and effectively avoid phase separation. Moreover, polysiloxane often plays a major role in the condensed phase of the flame retardant process. However, the flame retardant efficiency of a single silicon element is low. Boron-based flame retardants also mainly play a flame retardant role in the condensed phase. The compound use of silicon-based flame retardants and boron-based flame retardants has a synergistic effect. Phosphorus-based flame retardants are ideal substitutes for halogen-containing flame retardants. They have the advantages of high efficiency, low smoke, low toxicity and low volatility. Thermal decomposition can produce a large number of phosphorus-containing free radicals (such as ·P and ·PO) to quench combustible high-energy free radicals, and the flame retardant efficiency is very high. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a trapezoidal phosphorus-containing polyborosiloxane flame retardant and a preparation method and application thereof. The trapezoidal phosphorus-containing polyborosiloxane flame retardant of the present invention significantly improves the flame retardancy of epoxy resin cured products, while improving the mechanical properties and heat resistance of epoxy resin cured products, reducing the maximum thermal decomposition rate of the resin cured products, and can also increase the residual carbon rate of the resin cured products at high temperatures, and has broad application prospects in the fields of adhesive materials, composite materials, copper clad laminate materials, and electronic packaging materials.

[0006] The technical solution of the present invention is as follows:

[0007] The first aspect of the present invention provides a trapezoidal phosphorus-containing polyborosiloxane flame retardant, the general structural formula of the trapezoidal phosphorus-containing polyborosiloxane flame retardant is shown in the following formula (I):

[0008]

[0009] in,

[0010] The p and m are independently selected from integers between 1 and 20, and the q and n are independently selected from integers between 1 and 6;

[0011] The R is selected from One or more of .

[0012] Preferably, in the trapezoidal phosphorus-containing polyborosiloxane flame retardant, the mass fraction of phosphorus element is 0.84wt%-11.74wt%.

[0013] Preferably, in the trapezoidal phosphorus-containing polyborosiloxane flame retardant, the mass fraction of boron element is 0.26wt%-1.31wt%.

[0014] The second aspect of the present invention provides a method for preparing the trapezoidal phosphorus-containing polysiloxane flame retardant described in the first aspect, the preparation method comprising the following steps:

[0015] (1) mixing water, anhydrous potassium carbonate, and solvent I until the anhydrous potassium carbonate is dissolved, adding boric acid, mixing, and then dropwise adding silane monomer, reacting under a nitrogen atmosphere, removing residual solvent I after the reaction to obtain a crude product, and post-treating to obtain epoxy reminding polyborosiloxane;

[0016] (2) mixing the phosphorus-containing monomer, the catalyst, the solvent II, and the epoxy ladder polysiloxane of step (1), and subjecting them to condensation reflux reaction. After the reaction is completed, concentrating the mixture, and drying the obtained precipitate to obtain a ladder-shaped phosphorus-containing polysiloxane flame retardant.

[0017] Preferably, in step (1), the molar ratio of the water to the anhydrous potassium carbonate is 800-900:1; the volume ratio of the water to the solvent I is 1:1-2;

[0018] The solvent I includes one or more of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, acetone, and 2-butanone.

[0019] Preferably, in step (1), the molar ratio of the water, the boric acid and the silane monomer is 30:1-3:10;

[0020] The silane monomer includes trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane;

[0021] The reaction temperature is 25-80°C and the reaction time is 6-72h;

[0022] The post-treatment comprises: dissolving the crude product with dichloromethane, washing, drying, filtering, removing solvent I, and vacuum drying for 10-24 hours.

[0023] Preferably, in step (2), the phosphorus-containing monomer includes one or more of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-hydride, diphenylphosphine oxide, diethyl phosphite, and diphenyl phosphite;

[0024] The catalyst includes one or more of triphenylphosphine, N,N-dimethylbenzylamine, and tetrabutylammonium bromide;

[0025] The solvent II includes one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,4-dioxane;

[0026] The amount of the solvent II is to ensure that the total concentration of the epoxy ladder polysiloxane and the phosphorus-containing monomer is 1-5 g / mL;

[0027] The molar ratio of the epoxy group in the epoxy ladder polysiloxane to the phosphorus-containing monomer is 10:1-9;

[0028] The amount of the catalyst used is 0.5-2.5% of the mass of the phosphorus-containing monomer;

[0029] The temperature of the condensation reflux reaction is 90-120° C., and the time is 6-12 hours; the drying is vacuum drying, and the drying temperature is 40-60° C., and the time is 12-24 hours.

[0030] The third aspect of the present invention provides an epoxy composition, which comprises the following raw materials in parts by weight:

[0031]

[0032]

[0033] The trapezoidal phosphorus-containing polyborosiloxane is the trapezoidal phosphorus-containing polyborosiloxane flame retardant described in the first aspect, or the trapezoidal phosphorus-containing polyborosiloxane flame retardant prepared by the preparation method described in the second aspect.

[0034] Preferably, the epoxy resin includes one or more of bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, novolac epoxy resin, aliphatic glycidyl ether epoxy resin, and aliphatic epoxy resin;

[0035] The curing agent includes an anhydride curing agent or an amine curing agent;

[0036] The curing accelerator includes one or more of N,N-dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, acetylacetone metal salt, triphenylphosphine and phosphonium salt thereof, substituted urea, adduct of aromatic isocyanate and imidazole compound, active tri(2-ethylhexanoate)chromium, organic acid salt-amine complex, 1,8-diaza-bicyclo(5,4,0)-7-undecene, 2-thiolbenzothiazole, peroxide, thiourea and its derivatives, cycloalkyl imidazoline, 2-phenyl imidazoline, aromatic tertiary amine containing epoxy group, titanate accelerator, ferrocenyl accelerator and chromium halide-acid anhydride complex.

[0037] The fourth aspect of the present invention provides an application of the epoxy resin described in the third aspect, wherein the epoxy resin is used as an adhesive, and the adhesive is used for adhesive materials, composite materials, copper clad laminates, and electronic packaging materials.

[0038] The beneficial technical effects of the present invention are:

[0039] The trapezoidal phosphorus-containing polyborosiloxane flame retardant of the present invention can significantly improve the flame retardancy of epoxy resin cured products, and is expected to be applied in the fields of adhesive materials, composite materials, copper-clad laminate materials and electronic packaging materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 1H NMR curve of the ladder-shaped epoxy polyborosiloxane in Example 1 of the present invention.

[0041] Figure 2 is the ladder-shaped epoxy polyborosiloxane in Example 1 of the present invention 29 Si NMR curve.

[0042] Figure 3 This is a Fourier transform infrared spectrum of the ladder-shaped epoxy polyborosiloxane in Example 1 of the present invention.

[0043] Figure 4 This is a Fourier transform infrared spectrum of the trapezoidal phosphorus-containing polyborosiloxane in Example 1 of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be described in detail below in conjunction with the embodiments.

[0045] In the present invention, the main chain structure of the prepared flame retardant contains a large number of flexible mesh Si-O-Si structures. Compared with ordinary polysiloxanes, ladder polysiloxanes have better heat resistance, oxidation resistance, etc. After being added to the resin and cured, it can significantly enhance the mechanical properties of the resin cured product and maintain good heat resistance, and can significantly improve the bending strength and impact strength. At the same time, the phosphoric acid substances produced by the thermal decomposition of the phosphorus-containing structure can promote the dehydration and carbonization of the matrix resin in the early stage to quickly form a carbon layer. The silicon-containing structure and the boron-containing structure also help to form a stable and dense carbon layer. The carbon layer can effectively reduce heat transfer and protect the matrix resin, so it can significantly reduce the maximum thermal decomposition rate R of the resin cured product. max , and at the same time can improve the residual carbon rate of the resin cured product at 800℃.

[0046] The present invention will be further described below by way of examples and the like.

[0047] Embodiment 1:

[0048] A trapezoidal phosphorus-containing polyborosiloxane flame retardant, the preparation method of which is as follows:

[0049] (1) 89.8 mg (0.65 mmol) of potassium carbonate was dissolved in a mixed solution of 9.7 mL (0.54 mol) of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 1.1 g (0.0175 mol) of boric acid was added and fully dissolved, 43.0 g (0.175 mol) of trimethoxy [2- (7-oxabicyclo [4.1.0] heptane 3-3 yl) ethyl] silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, and the crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, which is a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms is 10:1.

[0050] (2) 31.47 g (containing 0.173 mol of epoxy groups) of epoxy polysiloxane, 31.59 g (0.156 mol) of diphenylphosphine oxide, 0.71 g of triphenylphosphine and 144.2 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 h to obtain a trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-91 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers. The flame retardant is a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron at the same time, wherein the molar ratio of silicon atoms to boron atoms is 10:1, the phosphorus-containing structure (diphenylphosphine oxide) in the side groups accounts for 90% (90% of the total number of side groups, and the percentages are all in the number below), and the epoxy groups account for 10%.

[0051] Embodiment 2:

[0052] A trapezoidal phosphorus-containing polyborosiloxane flame retardant, the preparation method of which is as follows:

[0053] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 2.2 g (0.035 mol) of boric acid was added and fully dissolved, 43.0 g of trimethoxy [2- (7-oxabicyclo [4.1.0] heptane 3-3 yl) ethyl] silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, and the crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, and a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:2.

[0054] (2) 31.47 g (containing 0.173 mol of epoxy groups) of epoxy polysiloxane, 31.59 g (0.156 mol) of diphenyl phosphine oxide, 0.71 g of triphenylphosphine and 144.2 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 hours. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 hours to obtain a phosphorus-containing polyborosiloxane flame retardant FR1-92 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:2, the phosphorus-containing structure (diphenyl phosphine oxide) in the side groups accounted for 90%, and the epoxy groups accounted for 10%.

[0055] Embodiment 3:

[0056] A trapezoidal phosphorus-containing polysiloxane flame retardant, the preparation method of which is as follows:

[0057] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 3.2 g (0.525 mol) of boric acid was added and fully dissolved, 43.0 g of trimethoxy [2- (7-oxabicyclo [4.1.0] heptane 3-3 yl) ethyl] silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25°C for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, which was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, which is a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms is 10:3.

[0058] (2) 31.47 g (containing 0.173 mol of epoxy groups) of epoxy polysiloxane, 3.51 g (0.0173 mol) of diphenylphosphine oxide, 0.35 g of triphenylphosphine and 70.8 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 h to obtain a trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-13 in which 10% of the epoxy groups were replaced by phosphorus-containing monomers and the molar proportion of boron structure in the main chain was 30%, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron at the same time, wherein the molar ratio of silicon atoms to boron atoms was 10:3, the phosphorus-containing structure (diphenylphosphine oxide) in the side groups accounted for 10%, and the epoxy groups accounted for 90%.

[0059] Embodiment 4:

[0060] A trapezoidal phosphorus-containing polysiloxane flame retardant, the preparation method of which is as follows:

[0061] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 3.2 g of boric acid was added and fully dissolved, 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, which was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, which is a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms is 10:3.

[0062] (2) 31.47 g of epoxy polysiloxane (containing 0.173 mol of epoxy groups), 17.55 g (0.0865 mol) of diphenylphosphine oxide, 0.51 g of triphenylphosphine and 103.4 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 h to obtain a trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-53 in which 50% of the epoxy groups were replaced by phosphorus-containing monomers and the molar proportion of boron-containing structures in the main chain was 30%, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron at the same time, wherein the molar ratio of silicon atoms to boron atoms was 10:3, the phosphorus-containing structure (diphenylphosphine oxide) in the side groups accounted for 50%, and the epoxy groups accounted for 50%.

[0063] Embodiment 5:

[0064] A trapezoidal phosphorus-containing polyborosiloxane flame retardant, the preparation method of which is as follows:

[0065] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 3.2 g of boric acid was added and fully dissolved, 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, and the crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, and a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3.

[0066] (2) 31.47 g of epoxy polysiloxane (containing 0.173 mol of epoxy groups), 31.59 g (0.156 mol) of diphenyl phosphine oxide, 0.71 g of triphenylphosphine and 144.2 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 h to obtain a trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-93 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers and the molar proportion of boron-containing structures in the main chain was 30%, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3, the phosphorus-containing structure (diphenyl phosphine oxide) in the side groups accounted for 90%, and the epoxy groups accounted for 10%.

[0067] Embodiment 6:

[0068] A trapezoidal phosphorus-containing polyborosiloxane flame retardant, the preparation method of which is as follows:

[0069] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 3.2 g of boric acid was added and fully dissolved, 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, and the crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, and a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3.

[0070] (2) 31.47 g epoxy polysiloxane (containing 0.173 mol epoxy groups), 33.75 g (0.156 mol)

[0071] 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-hydride, 0.74g triphenylphosphine and 148.4mL N,N-dimethylformamide were added to the flask at once and reacted at 100°C for 10h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24h to obtain a trapezoidal phosphorus-containing polyborosiloxane flame retardant FR2-93 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers and the molar proportion of boron structure in the main chain was 30%, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron was obtained, wherein the molar ratio of silicon atoms to boron atoms was 10:3, the phosphorus-containing structure (DOPO) in the side group accounted for 90%, and the epoxy group accounted for 10%.

[0072] Embodiment 7:

[0073] A trapezoidal phosphorus-containing polyborosiloxane flame retardant, the preparation method of which is as follows:

[0074] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 3.2 g of boric acid was added and fully dissolved, 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, and the crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, and a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3.

[0075] (2) 31.47 g (containing 0.173 mol of epoxy groups) of epoxy polysiloxane, 17.20 g (0.156 mol) of dimethyl phosphite, 0.53 g of triphenylphosphine and 53.5 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 h to obtain a trapezoidal phosphorus-containing polyborosiloxane flame retardant FR3-93 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers and the molar proportion of boron structure in the main chain was 30%, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3, the phosphorus-containing structure (dimethyl phosphite) in the side groups accounted for 90%, and the epoxy groups accounted for 10%.

[0076] Embodiment 8:

[0077] A trapezoidal phosphorus-containing polyborosiloxane flame retardant, the preparation method of which is as follows:

[0078] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 3.2 g of boric acid was added and fully dissolved, 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, and the crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, and a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3.

[0079] (2) 31.47 g (containing 0.173 mol of epoxy groups) of epoxy polysiloxane, 21.57 g (0.156 mol) of diethyl phosphite, 0.59 g of triphenylphosphine and 59.2 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 h to obtain a trapezoidal phosphorus-containing polyborosiloxane flame retardant FR4-93 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers and the molar proportion of boron structure in the main chain was 30%, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3, the phosphorus-containing structure (diethyl phosphite) in the side groups accounted for 90%, and the epoxy groups accounted for 10%.

[0080] Embodiment 9:

[0081] A trapezoidal phosphorus-containing polyborosiloxane flame retardant, the preparation method of which is as follows:

[0082] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution, 3.2 g of boric acid was added and fully dissolved, 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 h. After the reaction was completed, the residual solvent was removed to obtain a crude product, and the crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 h after the solvent was removed to obtain epoxy polyborosiloxane LASQ, and a trapezoidal polysiloxane containing both silicon and boron, wherein the molar ratio of silicon atoms to boron atoms was 10:3.

[0083] (2) 31.47 g (containing 0.173 mol of epoxy groups) of epoxy polysiloxane, 36.62 g (0.156 mol) of diphenyl phosphite, 0.79 g of triphenylphosphine and 78.6 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100°C for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60°C for 24 h to obtain a phosphorus-containing polyborosiloxane flame retardant FR5-93 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers and the molar proportion of boron-containing structures in the main chain was 30%, and a trapezoidal polysiloxane flame retardant containing phosphorus, silicon and boron was obtained, wherein the molar ratio of silicon atoms to boron atoms was 10:3, the phosphorus-containing structure (diethyl phosphite) in the side groups accounted for 90%, and the epoxy groups accounted for 10%.

[0084] Comparative Example 1:

[0085] A trapezoidal phosphorus-containing polysiloxane flame retardant, the preparation method of which is as follows:

[0086] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution. 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 hours. After the reaction, the residual solvent was removed to obtain a crude product. The crude product was redissolved in dichloromethane, washed, dried, filtered, and vacuum dried for 10-24 hours after the solvent was removed to obtain epoxy polysiloxane LASQ (boron-free ladder polysiloxane).

[0087] (2) 31.0 g of epoxy polysiloxane, 31.59 g of diphenylphosphine oxide, 0.71 g of triphenylphosphine and 144.2 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100° C. for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60° C. for 24 h to obtain a trapezoidal phosphorus-containing polysiloxane flame retardant FR1-9 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers, and a trapezoidal polysiloxane flame retardant containing only phosphorus and silicon, in which the phosphorus-containing structure (diphenylphosphine oxide) in the side group accounted for 90% and the epoxy group accounted for 10%.

[0088] Comparative Example 2:

[0089] A trapezoidal phosphorus-containing polysiloxane flame retardant, the preparation method of which is as follows:

[0090] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution. 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 hours. After the reaction, the residual solvent was removed to obtain a crude product. The crude product was redissolved in dichloromethane, washed, dried, filtered, and dried in vacuum for 10-24 hours after the solvent was removed to obtain epoxy polysiloxane LASQ (silicon-only trapezoidal polysiloxane).

[0091] (2) 31.0 g of epoxy polysiloxane, 33.75 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-hydride, 0.74 g of triphenylphosphine and 148.4 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100° C. for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60° C. for 24 h to obtain a trapezoidal phosphorus-containing polysiloxane flame retardant FR2-9 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers, and a trapezoidal polysiloxane flame retardant containing only phosphorus and silicon, in which the phosphorus-containing structure (DOPO) in the side group accounted for 90% and the epoxy group accounted for 10%.

[0092] Comparative Example 3:

[0093] A trapezoidal phosphorus-containing polysiloxane flame retardant, the preparation method of which is as follows:

[0094] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution. 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 hours. After the reaction, the residual solvent was removed to obtain a crude product. The crude product was redissolved in dichloromethane, washed, dried, filtered, and dried in vacuum for 10-24 hours after the solvent was removed to obtain epoxy polysiloxane LASQ (silicon-only trapezoidal polysiloxane).

[0095] (2) 31.0 g of epoxy polysiloxane, 17.20 g of dimethyl phosphite, 0.53 g of triphenylphosphine and 53.5 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100° C. for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60° C. for 24 h to obtain a trapezoidal phosphorus-containing polysiloxane flame retardant FR3-9 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers, and a trapezoidal polysiloxane flame retardant containing only phosphorus and silicon, in which the phosphorus-containing structure (dimethyl phosphite) accounted for 90% of the side groups and the epoxy group accounted for 10%.

[0096] Comparative Example 4:

[0097] A trapezoidal phosphorus-containing polysiloxane flame retardant, the preparation method of which is as follows:

[0098] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution. 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 hours. After the reaction, the residual solvent was removed to obtain a crude product. The crude product was redissolved in dichloromethane, washed, dried, filtered, and dried in vacuum for 10-24 hours after the solvent was removed to obtain epoxy polysiloxane LASQ (silicon-only trapezoidal polysiloxane).

[0099] (2) 31.0 g of epoxy polysiloxane, 21.57 g of diethyl phosphite, 0.59 g of triphenylphosphine and 59.2 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100° C. for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60° C. for 24 h to obtain a trapezoidal phosphorus-containing polysiloxane flame retardant FR4-9 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers, and a trapezoidal polysiloxane flame retardant containing only phosphorus and silicon, in which the phosphorus-containing structure (diethyl phosphite) accounted for 90% of the side groups and the epoxy group accounted for 10%.

[0100] Comparative Example 5:

[0101] A trapezoidal phosphorus-containing polysiloxane flame retardant, the preparation method of which is as follows:

[0102] (1) 89.8 mg of potassium carbonate was dissolved in a mixed solution of 9.7 mL of deionized water and 12.9 mL of tetrahydrofuran and stirred to form a mixed solution. 43.0 g of trimethoxy[2-(7-oxabicyclo[4.1.0]heptyl3-3-yl)ethyl]silane was added dropwise to the mixed solution under a nitrogen atmosphere, and the mixture was stirred at 25° C. for 72 hours. After the reaction, the residual solvent was removed to obtain a crude product. The crude product was redissolved in dichloromethane, washed, dried, filtered, and dried in vacuum for 10-24 hours after the solvent was removed to obtain epoxy polysiloxane LASQ (silicon-only trapezoidal polysiloxane).

[0103] (2) 31.0 g of epoxy polysiloxane, 36.62 g of diphenyl phosphite, 0.79 g of triphenylphosphine and 78.6 mL of N,N-dimethylformamide were added to a flask at once and reacted at 100° C. for 10 h. The solution after the reaction was concentrated and then precipitated in anhydrous ether. The precipitate was vacuum dried at 60° C. for 24 h to obtain a trapezoidal phosphorus-containing polysiloxane flame retardant FR5-9 in which 90% of the epoxy groups were replaced by phosphorus-containing monomers, and a trapezoidal polysiloxane flame retardant containing only phosphorus and silicon, in which the phosphorus-containing structure (diphenyl phosphite) accounted for 90% of the side groups and the epoxy group accounted for 10%.

[0104] Application Example 1:

[0105] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0106] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 33.00g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-91 obtained in Example 1 are melted and mixed uniformly at 120°C, cooled to 60°C, 87.01g of curing agent methyl hexahydrophthalic anhydride and 1g of curing accelerator N,N-dimethylbenzylamine are mixed uniformly and poured into the epoxy resin. Continue stirring for 30 minutes. After the resin and curing agent are mixed uniformly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR1-91 of 15wt% can be obtained.

[0107] Application Example 2:

[0108] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0109] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 46.90g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-91 obtained in Example 1 are melt-mixed at 120°C and then cooled to 60°C. 87.60g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR1-91 of 20wt% can be obtained.

[0110] Application Example 3:

[0111] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0112] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 33.00g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-92 obtained in Example 2 are melt-mixed at 120°C and then cooled to 60°C. 87.01g of curing agent methyl hexahydrophthalic anhydride and 1g of curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR1-92 of 15wt%.

[0113] Application example 4:

[0114] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0115] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 46.90g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-92 obtained in Example 2 are melt-mixed at 120°C and then cooled to 60°C. 87.60g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR1-92 of 20wt% can be obtained.

[0116] Application Example 5:

[0117] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0118] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 36.53g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-13 obtained in Example 3 are melt-mixed at 120°C, cooled to 60°C, 107.00g of curing agent methyl hexahydrophthalic anhydride and 1g of curing accelerator N, N-dimethylbenzylamine are mixed evenly, poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR1-13 of 15wt% can be obtained.

[0119] Application Example 6:

[0120] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0121] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 54.38g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-13 obtained in Example 3 are melt-mixed at 120°C and then cooled to 60°C. 117.52g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR1-13 of 20wt%.

[0122] Application Example 7:

[0123] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0124] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 34.77g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-53 obtained in Example 4 are melt-mixed at 120°C and then cooled to 60°C. 97.04g of curing agent methyl hexahydrophthalic anhydride and 1g of curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR1-53 of 15wt%.

[0125] Application Example 8:

[0126] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0127] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 50.55g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant obtained in Example 4 are melt-mixed at 120°C and then cooled to 60°C. 102.20g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an FR1-53 addition amount of 20wt% can be obtained.

[0128] Application Example 9:

[0129] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0130] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 33.00g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-93 obtained in Example 5 are melt-mixed at 120°C and then cooled to 60°C. 87.01g of curing agent methyl hexahydrophthalic anhydride and 1g of curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR1-93 of 15wt%.

[0131] Application Example 10:

[0132] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0133] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 46.90g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-93 obtained in Example 5 are melt-mixed at 120°C and then cooled to 60°C. 87.60g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR1-93 of 20wt%.

[0134] Application Example 11:

[0135] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0136] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 33.00g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR2-93 obtained in Example 6 are melt-mixed at 120°C and then cooled to 60°C. 87.01g of curing agent methyl hexahydrophthalic anhydride and 1g of curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR2-93 of 15wt%.

[0137] Application Example 12:

[0138] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0139] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 46.90g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR2-93 obtained in Example 6 are melt-mixed at 120°C and then cooled to 60°C. 87.60g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR2-93 of 20wt%.

[0140] Application Example 13:

[0141] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0142] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 47.01g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR3-93 obtained in Example 7 are melt-mixed at 120°C and then cooled to 60°C. 88.04g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR3-93 of 20wt% can be obtained.

[0143] Application Example 14:

[0144] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0145] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 46.97g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR4-93 obtained in Example 8 are melt-mixed at 120°C and then cooled to 60°C. 87.88g of curing agent methyl hexahydrophthalic anhydride and 1g of curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR4-93 of 20wt%.

[0146] Application Example 15:

[0147] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0148] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 46.84g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR5-93 obtained in Example 9 are melt-mixed at 120°C and then cooled to 60°C. 87.36g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR5-93 of 20wt% can be obtained.

[0149] Application Example 16:

[0150] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0151] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 6.63g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-92 obtained in Example 2 are melt-mixed at 120°C and then cooled to 100°C. 25.97g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR1-92 of 5wt%.

[0152] Application Example 17:

[0153] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0154] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 6.63g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-93 obtained in Example 5 are melt-mixed at 120°C and then cooled to 100°C. 25.97g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of 5wt% of FR1-93.

[0155] Application Example 18:

[0156] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0157] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 6.63g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR2-93 obtained in Example 6 are melt-mixed at 120°C and then cooled to 100°C. 25.97g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of 5wt% of FR2-93.

[0158] Application Example 19:

[0159] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0160] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 6.63g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR3-93 obtained in Example 7 are melt-mixed at 120°C and then cooled to 100°C. 25.97g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of 5wt% of FR3-93 can be obtained.

[0161] Application Example 20:

[0162] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0163] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 6.63g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR4-93 obtained in Example 8 are melt-mixed at 120°C and then cooled to 100°C. 25.97g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of 5wt% of FR4-93.

[0164] Application Example 21:

[0165] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0166] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 6.63g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR5-93 obtained in Example 9 are melt-mixed at 120°C and then cooled to 100°C. 25.97g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR5-93 of 5wt% can be obtained.

[0167] Application Example 22:

[0168] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0169] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (F51, epoxy equivalent weight EEW = 196g·eq -1) and 3.89g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-92 obtained in Example 2 are melt-mixed at 120°C and then cooled to 100°C. 25.90g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of FR1-92 of 3wt%.

[0170] Application Example 23:

[0171] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0172] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 3.89g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR1-93 obtained in Example 5 are melt-mixed at 120°C and then cooled to 100°C. 25.90g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of 3wt% of FR1-93.

[0173] Application Example 24:

[0174] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0175] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 3.89g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR2-93 obtained in Example 6 are melt-mixed at 120°C and then cooled to 100°C. 25.90g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of 3wt% of FR2-93.

[0176] Application Example 25:

[0177] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0178] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 3.89g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR3-93 obtained in Example 7 are melt-mixed at 120°C and then cooled to 100°C. 25.90g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of 3wt% of FR3-93 can be obtained.

[0179] Application Example 26:

[0180] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0181] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 3.89g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR4-93 obtained in Example 8 are melt-mixed at 120°C and then cooled to 100°C. 25.90g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of 3wt% of FR4-93.

[0182] Application Example 27:

[0183] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0184] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 3.89g of the trapezoidal phosphorus-containing polyborosiloxane flame retardant FR5-93 obtained in Example 9 are melt-mixed at 120°C and then cooled to 100°C. 25.90g of the curing agent diaminodiphenylmethane is added to the epoxy resin, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are evenly mixed, pour them into a preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain an epoxy resin cured product with an addition amount of 3wt% of FR5-93.

[0185] Comparative application example 1:

[0186] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0187] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ), 85g of curing agent methyl hexahydrophthalic anhydride and 1.1g of curing accelerator N,N-dimethylbenzylamine were melted and mixed uniformly at 60°C, placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing was performed according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h; after cooling and demolding, the pure epoxy resin cured product can be obtained.

[0188] Comparative application example 2:

[0189] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0190] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 46.91g of the trapezoidal phosphorus-containing polysiloxane flame retardant FR1-90 obtained in Comparative Example 1 are melt-mixed at 120°C and then cooled to 60°C. 87.64g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and the curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR1-90 of 20wt% can be obtained.

[0191] Comparative application example 3:

[0192] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0193] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 46.89g of the trapezoidal phosphorus-containing polysiloxane flame retardant FR2-90 obtained in Comparative Example 2 are melt-mixed at 120°C and then cooled to 60°C. 87.56g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and the curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR2-90 of 20wt% can be obtained.

[0194] Comparative application example 4:

[0195] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0196] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 47.03g of the trapezoidal phosphorus-containing polysiloxane flame retardant FR3-90 obtained in Comparative Example 3 are melt-mixed at 120°C and then cooled to 60°C. 88.12g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and the curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an FR3-90 addition amount of 20wt% can be obtained.

[0197] Comparative application example 5:

[0198] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0199] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 46.99g of the trapezoidal phosphorus-containing polysiloxane flame retardant FR4-90 obtained in Comparative Example 4 are melt-mixed at 120°C and then cooled to 60°C. 87.96g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and the curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an FR4-90 addition amount of 20wt% can be obtained.

[0200] Comparative application example 6:

[0201] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0202] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1) and 46.88g of the trapezoidal phosphorus-containing polysiloxane flame retardant FR5-90 obtained in Comparative Example 5 are melt-mixed at 120°C and then cooled to 60°C. 87.52g of the curing agent methyl hexahydrophthalic anhydride and 1g of the curing accelerator N,N-dimethylbenzylamine are mixed evenly and poured into the epoxy resin and stirred for 30 minutes. After the resin and the curing agent are mixed evenly, they are placed in a 60°C vacuum oven for degassing for 20 minutes, poured into a preheated mold, degassed for another 20 minutes, and then placed in a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 80°C×1h, 100°C×1h, 120°C×1h, and 140°C×4h. After the curing is completed, cool and demould and sample, and an epoxy resin cured product with an addition amount of FR4-90 of 20wt% can be obtained.

[0203] Comparative application example 7:

[0204] An epoxy resin cured product, the contents of the components contained in it are shown in the preparation method,

[0205] The preparation method of the epoxy resin cured product is as follows: 100g of epoxy resin (E51, epoxy equivalent weight EEW = 196g·eq -1 ) and 25.97g curing agent diaminodiphenylmethane are mixed evenly at 90°C, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are mixed evenly, pour them into the preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After curing, cool and demould and sample to obtain pure epoxy resin cured product.

[0206] Comparative application example 8:

[0207] 100g epoxy resin (F51, epoxy equivalent weight EEW = 196g eq -1 ) and 25.80g curing agent diaminodiphenylmethane are mixed evenly at 90°C, and the mixed resin is vacuum degassed with an oil pump while stirring. After the resin and curing agent are mixed evenly, pour them into the preheated mold, degasset for 20 minutes, and then put them into a high-temperature oven for staged curing. Curing is carried out according to the curing procedure of 120°C×2h, 140°C×2h, 160°C×2h, and 180°C×1h. After the curing is completed, cool and demould and sample to obtain pure epoxy resin cured product.

[0208] Test example:

[0209] The epoxy resin cured products prepared in the application examples and the comparative application examples were subjected to vertical combustion performance tests, and the test results are shown in Table 1.

[0210] Table 1 Performance test of epoxy resin cured products of application examples and comparative application examples

[0211]

[0212] As shown in Table 1, the resins and curing agents used in Application Example 2, Application Example 4, Application Example 8, Application Example 9, Application Example 10, Application Example 12, Application Example 13, Application Example 14, Application Example 15, Comparative Application Example 1 and Comparative Application Example 2 are all bisphenol A epoxy resin E51 and methyl sulfhydrylphthalic anhydride. Among them, the addition amount of the flame retardant in Application Example 2, Application Example 4 and Application Example 10 is 20wt%, and the difference is that the ratio of silicon-containing structure to boron-containing structure in phosphorus-containing ladder polyborosiloxane is different, which is 10:1, 10:2 and 10:3 respectively. The test results show that as the proportion of boron-containing structure increases, the flame retardant properties of epoxy resin cured product are significantly improved. The amount of flame retardant added in Application Examples 8 and 10 is 20wt%, and the difference is that the phosphorus-containing structure in the phosphorus-containing trapezoidal polyborosiloxane side group has a different proportion, accounting for 50% and 90% respectively. According to the test results, under the same amount of flame retardant added, the more phosphorus-containing structures in the flame retardant, the better the flame retardant properties of the epoxy cured product. The amount of flame retardant added in Application Examples 10, 12, 13, 14 and 15 is 20wt%, and the difference is that the phosphorus-containing structure in the phosphorus-containing trapezoidal polyborosiloxane side group is different. According to the test results, Application Examples 10, 12 and 15 all have excellent flame retardant properties, while Application Examples 13 and 14 have poor flame retardant properties. This is mainly because the phosphorus-containing structures in Application Examples 10, 12 and 15 decompose during combustion to produce phosphorus oxygen free radicals that can quench combustible free radicals, and the phosphoric acid substances produced by the decomposition can promote the dehydration of the matrix into carbon; while the phosphorus-containing structures in Application Examples 13 and 14 only play a role in the condensed phase, and the gas phase effect is very weak. Therefore, in comparison, the phosphorus-containing monomers used in the flame retardants in Application Examples 10, 12 and 15 can provide more effective flame retardant properties for epoxy resin cured products. Compared with Comparative Application Example 1 (pure epoxy resin cured product, without flame retardant) and Comparative Application Example 2 (without boron in the flame retardant), Application Example 10 can significantly improve the flame retardant properties of epoxy resin cured products after adding flame retardant, and compared with flame retardants without adding boron, flame retardants with added boron elements have a more significant effect in improving the flame retardant properties of epoxy resin cured products. This is mainly because after the addition of the flame retardant, in addition to the effect of the phosphorus-containing structure, the main body of the flame retardant in the embodiment of the present invention is a large number of continuous network Si-O-Si structures. The silicon-containing fragments produced by decomposition during combustion will participate in the formation of the carbon layer, thereby ensuring the density and stability of the carbon layer; in addition, the boron-containing structure will decompose under heat to produce borates, which will melt at high temperatures to seal the surface of the burning object, forming a glass covering layer to further improve the stability of the carbon layer.

[0213] The resins and curing agents used in Application Example 16, Application Example 17, Application Example 18, Application Example 21 and Comparative Application Example 7 are bisphenol A epoxy resin E51 and diaminodiphenylmethane, respectively, wherein the amount of flame retardant added in Application Example 16, Application Example 17, Application Example 18 and Application Example 21 is 5wt%, and the resin cured material in Comparative Application Example 7 does not contain flame retardant; the resins and curing agents used in Application Example 22, Application Example 23, Application Example 24, Application Example 27 and Comparative Application Example 8 are phenolic epoxy resin F51 and diaminodiphenylmethane, wherein the amount of flame retardant added in Application Example 22, Application Example 23, Application Example 24 and Application Example 27 is 3wt%, and the resin cured material in Comparative Application Example 8 does not contain flame retardant. As can be seen from Table 1, the flame retardant test results have the same trend as the epoxy resin E51 / methylhexahydrophthalic anhydride resin system, that is, the pure resin cured products do not have flame retardant properties, and good flame retardant effects can be achieved after adding the flame retardants in Example 1, Example 2, Example 5, Example 6 and Example 9.

[0214] The present invention also found in the test that under the condition of a single variable, the more the flame retardant is added, the better the flame retardant property of the resin cured product; the more the proportion of boron in the flame retardant, the better the flame retardant property of the prepared epoxy cured product; the more the proportion of phosphorus in the side group, the better the flame retardant property of the prepared resin cured product; the flame retardant prepared from DOPO, diphenyl phosphorus oxide and diphenyl phosphite has better performance than the flame retardant prepared from dimethyl phosphite and diethyl phosphite. Therefore, the above application examples and comparative application examples are used for illustration, and the remaining application examples not listed also have better comprehensive performance and are also within the protection scope of this application.

[0215] In addition, since the flame retardant contains a large amount of flexible and highly heat-resistant continuous network Si-O-Si structure, and the phosphorus-containing group reaction position is on the side chain of the flame retardant, it can significantly enhance the mechanical properties of the resin cured product and maintain good heat resistance after being added to the resin and cured. Therefore, the bending strength and impact strength are significantly improved, and the initial thermal decomposition temperature T 5％ And because the phosphoric acid substances produced by the thermal decomposition of the phosphorus-containing structure can promote the dehydration and carbonization of the matrix resin in the early stage to quickly form a carbon layer, the silicon-containing structure and the boron-containing structure also help to form a stable and dense carbon layer. The carbon layer can effectively reduce heat transfer and protect the matrix resin, thus significantly reducing the maximum thermal decomposition rate R of the resin cured product. max , and at the same time can improve the carbon residue rate of the resin cured product at 800°C.

[0216] In summary, the present invention successfully prepared a trapezoidal phosphorus-containing polyborosiloxane flame retardant, and after applying it to an epoxy resin system, an epoxy resin cured product with excellent flame retardant properties was obtained.

[0217] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A trapezoidal phosphorus-containing polyborosiloxane flame retardant, characterized in that: The general structural formula of the trapezoidal phosphorus-containing polyborosiloxane flame retardant is shown in the following formula (I): in, The p and m are independently selected from integers between 1 and 20, The q and n are independently selected from integers between 1 and 6; The R is selected from One or more of .

2. The trapezoidal phosphorus-containing polyborosiloxane flame retardant according to claim 1, characterized in that: In the trapezoidal phosphorus-containing polyborosiloxane flame retardant, the mass fraction of phosphorus element is 0.84wt%-11.74wt%.

3. The trapezoidal phosphorus-containing polyborosiloxane flame retardant according to claim 1, characterized in that: In the trapezoidal phosphorus-containing polyborosiloxane flame retardant, the mass fraction of boron element is 0.26wt%-1.31wt%.

4. A method for preparing the trapezoidal phosphorus-containing polysiloxane flame retardant according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: (1) mixing water, anhydrous potassium carbonate, and solvent I until the anhydrous potassium carbonate is dissolved, adding boric acid, mixing, and then dropwise adding silane monomer, reacting under a nitrogen atmosphere, removing residual solvent I after the reaction to obtain a crude product, and post-treating to obtain epoxy reminding polyborosiloxane; (2) mixing the phosphorus-containing monomer, the catalyst, the solvent II, and the epoxy ladder polysiloxane of step (1), and subjecting them to condensation reflux reaction. After the reaction is completed, concentrating the mixture, and drying the obtained precipitate to obtain a ladder-shaped phosphorus-containing polysiloxane flame retardant.

5. The preparation method according to claim 4, characterized in that: In step (1), the molar ratio of the water to the anhydrous potassium carbonate is 800-900:1; the volume ratio of the water to the solvent I is 1:1-2; The solvent I includes one or more of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, acetone, and 2-butanone.

6. The preparation method according to claim 4, characterized in that: In step (1), the molar ratio of the water, the boric acid and the silane monomer is 30:1-3:10; The silane monomer includes trimethoxy [2-(7-oxabicyclo[ 4.1.0]heptyl-3-yl)ethyl]silane; The reaction temperature is 25-80°C and the reaction time is 6-72h; The post-treatment comprises: dissolving the crude product with dichloromethane, washing, drying, filtering, removing solvent I, and vacuum drying for 10-24 hours.

7. The preparation method according to claim 4, characterized in that: In step (2), the phosphorus-containing monomer includes one or more of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-hydride, diphenylphosphine oxide, diethyl phosphite, and diphenyl phosphite; The catalyst includes one or more of triphenylphosphine, N,N-dimethylbenzylamine, and tetrabutylammonium bromide; The solvent II includes one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,4-dioxane; The amount of the solvent II is to ensure that the total concentration of the epoxy ladder polysiloxane and the phosphorus-containing monomer is 1-5 g / mL; The molar ratio of the epoxy group in the epoxy ladder polysiloxane to the phosphorus-containing monomer is 10:1-9; The amount of the catalyst used is 0.5-2.5% of the mass of the phosphorus-containing monomer; The temperature of the condensation reflux reaction is 90-120° C., and the time is 6-12 hours; the drying is vacuum drying, and the drying temperature is 40-60° C., and the time is 12-24 hours.

8. An epoxy composition, characterized in that The epoxy composition comprises the following raw materials in parts by weight: The trapezoidal phosphorus-containing polyborosiloxane is the trapezoidal phosphorus-containing polyborosiloxane flame retardant according to any one of claims 1 to 3, or the trapezoidal phosphorus-containing polyborosiloxane flame retardant prepared by the preparation method according to any one of claims 4 to 7.

9. The epoxy resin composition according to claim 8, characterized in that The epoxy resin includes one or more of bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, novolac epoxy resin, aliphatic glycidyl ether epoxy resin, and aliphatic epoxy resin; The curing agent includes an anhydride curing agent or an amine curing agent; The curing accelerator includes one or more of N,N-dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, acetylacetone metal salt, triphenylphosphine and phosphonium salt thereof, substituted urea, adduct of aromatic isocyanate and imidazole compound, active tri(2-ethylhexanoate)chromium, organic acid salt-amine complex, 1,8-diaza-bicyclo(5,4,0)-7-undecene, 2-thiolbenzothiazole, peroxide, thiourea and its derivatives, cycloalkyl imidazoline, 2-phenyl imidazoline, aromatic tertiary amine containing epoxy group, titanate accelerator, ferrocenyl accelerator and chromium halide-acid anhydride complex.

10. Use of the epoxy resin according to any one of claims 8 to 9, characterized in that: The epoxy resin is used as an adhesive, and the adhesive is used for adhesive materials, composite materials, copper-clad laminates, and electronic packaging materials.

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