Silane coupling agent modified ceramic flame retardant and epoxy resin high-fire-resistance flame-retardant composite material and method

Abstract

The invention provides a silane coupling agent modified ceramic flame retardant, an epoxy resin high-fire-resistance flame-retardant composite material and a method, the silane coupling agent modified ceramic flame retardant comprises a ceramic flame retardant filler, a silane coupling agent, a modified compound and a solvent, the modified compound comprises melamine cyanurate and ammonium polyphosphate; the epoxy resin high-fire-resistance flame-retardant composite material is prepared from the following raw materials: a silane coupling agent modified ceramic flame retardant, ethylene bis stearamide, a curing accelerator and an epoxy resin solution, and has the characteristics of high heat resistance, excellent flame retardance, good mechanical strength, environmental protection, safety and the like; wide application prospects can be realized in the fields of electronics, electrics, aerospace, buildings and the like. Particularly, the composite material shows huge market potential and value on occasions with high requirements on the flame retardant property of the material.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a silane coupling agent modified ceramic flame retardant and an epoxy resin high fire-resistant flame-retardant composite material and a method. Background Art

[0002] Most advanced resin-based composite materials are carbon fiber reinforced thermosetting resins, mainly epoxy resin (EP, the same below), polyester resin, vinyl ester, bismaleimide and other thermosetting resins. Among them, EP has the advantages of excellent process performance, strong adhesion, low shrinkage, and low price. As a traditional thermosetting resin, EP has good heat resistance, excellent mechanical properties, low shrinkage, high adhesion strength and other advantages, and is widely used in coatings, machinery, civil engineering, adhesion and other fields. However, its oxygen index (LOI) is only about 15.7%, which is very easy to burn, and it generates a large amount of heat when burning, burns quickly, and the flame is difficult to extinguish, which greatly hinders its application in fields with high flame retardancy requirements. Therefore, it is very necessary to improve the flame retardancy of epoxy resin.

[0003] In order to improve the flame retardant properties of epoxy resin and reduce the risk of fire, flame retardant EP composite materials have become materials that are urgently needed to be developed in many fields. Flame retardants are usually added to prepare flame retardant EP composite materials to make EP have good flame retardancy. Halogen flame retardants are currently used more frequently. Although halogen flame retardants have high flame retardancy and low prices, they are widely used in the field of flame retardancy. However, the combustion of halogen flame retardants will release a large amount of toxic gases and corrosive substances, resulting in their restricted use in many industries. Therefore, halogen-free, low smoke, and fire resistance are the research focuses of EP flame retardant modification.

[0004] For a long time in the past, organophosphorus flame retardants have become an alternative to improve the flame retardant properties of epoxy resins. However, they must undergo a series of surface treatments or be used in conjunction with other flame retardants to maintain mechanical properties because they have poor compatibility with polymers. Silicone flame retardants generate silicon-containing compounds such as silicon dioxide when burned. The low surface energy of silicon-containing compounds causes them to migrate to the surface of the substrate and form a dense char layer to protect the substrate and block the spread of heat and oxygen. However, its disadvantages are also very prominent. The silicon-oxygen bonds contained in silicone flame retardants are very flexible and will cause the glass transition temperature of the composite material to drop. Ceramic flame retardants are currently polymer material flame retardants that have both flame retardant and smoke suppression properties. They have multiple mechanisms such as low toxicity and flame retardancy and have been used in a variety of polymers (silicone rubber, polypropylene, etc.). Ceramic flame retardants are compounds mainly composed of elements such as silicon and calcium. When heated, they can decompose to produce crystal water, which can reduce the surface temperature while forming a carbon layer that isolates the flame, reducing the possibility of further erosion of the flame inside the material, and thus can play a certain flame retardant role on polymers for a considerable period of time.

[0005] Although ceramic flame retardants such as mica, wollastonite, lignite flakes and montmorillonite are used to flame retard EP and can improve the thermal stability of composite materials, they cannot quickly form a protective layer to isolate flames when used alone. At the same time, compared with nitrogen and phosphorus element flame retardants, ceramic flame retardants have lower flame retardant efficiency and poor flame retardant effect. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a silane coupling agent modified ceramic flame retardant and epoxy resin high fire retardant composite material and method. The epoxy resin high fire retardant composite material has the characteristics of high heat resistance, excellent flame retardant performance, good mechanical strength and environmental safety, and can have a wide range of application prospects in the fields of electronics, aerospace, construction, etc. In particular, in occasions where the flame retardant performance of the material is required to be high, the composite material will show huge market potential and value.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a silane coupling agent modified ceramic flame retardant, the raw materials comprising: a ceramic flame retardant filler, a silane coupling agent, a modified composite and a solvent, wherein: the modified composite comprises melamine cyanurate and ammonium polyphosphate, and the addition ratio of melamine cyanurate and ammonium polyphosphate is 1:4~1:2; the addition amount of the silane coupling agent accounts for 0.4%~1% of the mass of the ceramic flame retardant filler; the addition ratio of the modified composite and the silane coupling ceramic flame retardant is 1:3~1:1.

[0008] Calculated by mass fraction, the main components of ceramic flame retardant fillers are: 40%~50% calcium silicate, 20%~25% silicon dioxide, 15%~20% calcium carbonate, 5%~10% hydrated zinc borate, 3%~6% aluminum hydroxide, 3%~6% magnesium hydroxide, and 1%~3% hydrated calcium borate.

[0009] The present invention also provides a method for preparing a silane coupling agent modified ceramic flame retardant, the specific steps of which are as follows: The ceramic flame retardant filler and the silane coupling agent are added to the solvent, mixed and stirred until there is no obvious precipitation and no obvious floating particles on the liquid surface, and then heat treated to obtain a silane coupled ceramic flame retardant; Dissolving dried melamine cyanurate and ammonium polyphosphate in a solvent, adding a catalyst, performing a heat treatment reaction under a protective atmosphere, cooling to room temperature, filtering, and drying to obtain a modified composite; The modified composite and the silane coupling ceramic flame retardant are mixed to obtain the silane coupling agent modified ceramic flame retardant.

[0010] Furthermore, in the step of obtaining the silane coupled ceramic flame retardant, the heat treatment is performed at 60° C. for 1 hour, and then the temperature is raised to 120° C. for 2 hours.

[0011] Furthermore, in the step of obtaining the modified composite, the catalyst is tridecylamine added in an amount of 0.5% to 5%; after heating to 150°C to 180°C in a nitrogen environment, stirring the reaction at 200rpm to 600rpm for 1h to 3h, cooling to room temperature and filtering, and drying at 60°C for 8h to obtain the modified composite.

[0012] Furthermore, in the step of obtaining the silane coupling agent modified ceramic flame retardant, the modified composite and the silane coupling ceramic flame retardant are mixed at a rotation speed of 500 r / min to 800 rpm for 5 min to 10 min.

[0013] The present invention also provides an application of a silane coupling agent modified ceramic flame retardant in a highly fire-resistant and flame-retardant epoxy resin composite material.

[0014] The present invention also provides an epoxy resin high fire-resistant flame-retardant composite material, the raw materials of which include a silane coupling agent modified ceramic flame retardant, and the silane coupling agent modified ceramic flame retardant is the silane coupling agent modified ceramic flame retardant prepared by the above preparation method.

[0015] Furthermore, the raw materials also include ethylene bis(stearoyl)amine, a curing accelerator, and an epoxy resin solution, wherein the content of the silane coupling agent modified ceramic flame retardant in the epoxy resin solution is 30% to 50%, the content of ethylene bis(stearoyl)amine is 0.5% to 1%, and the content of the curing accelerator is 0.5% to 5%.

[0016] The present invention also provides a method for preparing an epoxy resin highly fire-resistant and flame-retardant composite material, the specific steps of which are as follows: Mix epoxy resin and methyltetrahydrophthalic anhydride in a mass ratio of 1:0.8 to 1:0.85, and stir at a speed of 500 r / min to 800 r / min for 5 min to 10 min in a vacuum environment of -1 MPa to -0.8 MPa to obtain an epoxy resin solution; Adding a silane coupling agent-modified ceramic flame retardant, ethylenebis( ... The precursor solution is subjected to three-stage temperature-raising curing to obtain an epoxy resin highly fire-resistant and flame-retardant composite material; The three-stage temperature rise curing is as follows: the first stage curing condition is: curing at 87℃~102℃ for 1.5h~2.5h; the second stage curing condition is curing at 110℃~130℃ for 1.5h~2.5h; the third stage curing condition is curing at 124℃~146℃ for 1.5h~2.5h; the temperature rise process of each stage is 0.2h~0.5h.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: The present invention provides a silane coupling agent modified ceramic flame retardant, the raw materials include: ceramic flame retardant filler, silane coupling agent, modified compound and solvent, through the modification of silane coupling agent, the surface energy of ceramic flame retardant (CFR) is effectively reduced, thereby significantly improving its compatibility with epoxy resin. This improvement in compatibility helps to enhance the overall performance of the composite material and ensure the uniform distribution of the flame retardant in the matrix. The modified ceramic flame retardant not only retains the original flame retardant properties, such as releasing crystal water and carbon dioxide when heated to reduce the surface temperature of the composite material and form a ceramic fireproof layer, but also further improves the flame retardant effect through the synergistic effect with melamine cyanurate (MCA) and ammonium polyphosphate (APP). The introduction of silane coupling agent also improves the dispersibility and fluidity of ceramic flame retardant during processing, making the preparation process of the composite material smoother and reducing waste and defective rate in production.

[0018] The present invention provides an epoxy resin high fire-resistant and flame-retardant composite material, wherein the selected resin is bisphenol A epoxy resin, specifically E51, with an epoxy value of 0.48-0.54, good heat resistance, and capable of withstanding temperatures above 200°C. The ceramic flame retardant (CFR) is modified by a silane coupling agent to reduce its surface energy and improve the compatibility of the ceramic flame retardant (CFR) with the epoxy resin; the introduction of ethylenebis(dimethylaminomethyl)amine makes the ceramic flame retardant (CFR) more uniformly dispersed in the matrix; and 2, 4, 6-tris(dimethylaminomethyl)phenol (DMP-30) can reduce the curing temperature of the epoxy resin and improve the mechanical strength of the epoxy resin. When a fire occurs, the ceramic flame retardant (CFR) will release crystalline water and carbon dioxide (CO2) when heated, reduce the surface temperature of the composite material, form a ceramic fireproof layer, and protect the substrate from direct contact with the flame; melamine cyanurate (MCA) releases nitrogen (N2), carbon dioxide (CO2) and water (H2O) during combustion; ammonium polyphosphate (APP) forms polyphosphoric acid during combustion, which promotes the formation of a stable surface carbon layer in the epoxy matrix. When the ceramic flame retardant (CFR), melamine cyanurate (MCA) and ammonium polyphosphate (APP) are mixed to modify the epoxy resin, it will expand slightly after the flame burns, release non-flammable gas, reduce the oxygen concentration on the surface of the material, and form a stable and dense protective layer to block the spread of flames, thereby achieving a good flame retardant effect. The maximum thermal decomposition temperature of the composite material measured by a thermogravimetric analyzer (TGA) is 401.6℃, and the residual rate is 57.42%; the limiting oxygen index of the composite material measured by a limiting oxygen index meter and a vertical combustion tester is 37.8%, and the combustion grade is V-0. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 TGA (a) and DTG (b) curves of Examples 1 to 3 and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0020] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Given the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work all fall within the scope of protection of the present invention.

[0021] The present invention provides an epoxy resin high fire-resistant flame-retardant composite material, the raw materials of which include: epoxy resin, silane coupling agent modified ceramic flame retardant, ethylene bis stearyl amine, 2, 4, 6-tris (dimethylaminomethyl) phenol (DMP-30), and the preparation method includes the following steps: Step 1: Preparation of silane coupling agent modified ceramic flame retardant 1) Weigh a certain amount of ceramic flame retardant filler (CFR) and add it to anhydrous ethanol solution in a beaker, and add a certain amount of silane coupling agent thereto, stir well and place in a blast drying oven for heat treatment to obtain a silane coupled ceramic flame retardant; As a preferred embodiment of the present invention, in step 1), the total amount of CFR is 100%, and the main components of CFR are calcium silicate (CaSiO3) 40%~50%, silicon dioxide (SiO2) 20%~25%, calcium carbonate (CaCO3) 15%~20%, hydrated zinc borate (2ZnO·3B2O3·3.5H2O) 5%~10%, aluminum hydroxide (Al(OH)3) 3%~6%, magnesium hydroxide (Mg(OH)2) 3%~6%, and hydrated calcium borate (2CaO·2B2O3·nH2O) 1%~3%.

[0022] As a preferred embodiment of the present invention, in step 1), the amount of silane coupling agent added is 0.4% to 1% of the mass of the ceramic flame retardant (CFR).

[0023] As a preferred embodiment of the present invention, in step 1), stirring should be performed until there is no obvious precipitation and no obvious floating particles on the liquid surface.

[0024] As a preferred embodiment of the present invention, in step 1), the heat treatment process is 60°C for 1 hour (to allow the silane coupling agent to fully react with the ceramic flame retardant at this temperature), and then the temperature is raised to 120°C for 2 hours (to evaporate the anhydrous ethanol used as the solvent).

[0025] 2) Preparation of modified composites 2.1) Dry melamine cyanurate (MCA) and ammonium polyphosphate (APP) in an oven at 60°C for 8 hours (because MCA and APP are susceptible to moisture, the moisture in MCA and APP should be removed before the experiment. Both are very stable at 100°C and will not undergo thermal decomposition or other reactions); 2.2) Melamine cyanurate (MCA) and ammonium polyphosphate (APP) in a ratio of 1:4 to 1:2 are dissolved in an organic solvent, and a catalyst is added at the same time. The temperature is raised to 150°C to 180°C under a nitrogen environment, and the reaction is continuously stirred at 200 to 600 rpm for 1 h to 3 h. After the reaction is completed, the mixture is cooled to room temperature and filtered with ethanol for 2 to 3 times, and then placed in an oven at 60°C for 8 h to obtain a modified composite.

[0026] As a preferred embodiment of the present invention, in step 2.2), the organic solvent is dimethyl sulfoxide; the catalyst should be tridecylamine, and the addition amount thereof is 0.5% to 5%; 3) The modified composite of step 2) and the silane coupling ceramic flame retardant of step 1) are mixed in a ratio of 1:3 to 1:1, and mixed for 5 min to 10 min at a rotation speed of 500 r / min to 800 rpm to obtain a silane coupling agent modified ceramic flame retardant.

[0027] As a preferred embodiment of the present invention, in step 3), mixing is carried out in a ball mill. Step 2: Preparation of epoxy resin high fire-resistant flame-retardant composite material 1) Weigh a certain amount of epoxy resin and add a certain amount of curing agent methyltetrahydrophthalic anhydride solution into a beaker, then place it in a vacuum environment and stir until it is completely blended to obtain an epoxy resin solution.

[0028] As a preferred embodiment of the present invention, in step 1), the mass ratio of epoxy resin to methyltetrahydrophthalic anhydride is 1:0.8 to 1:0.85.

[0029] As a preferred embodiment of the present invention, in step 1), the vacuum environment is -1Mpa~-0.8Mpa, the stirring speed is 500r / min~800r / min, and the stirring time is 5min~10min.

[0030] 2) Add a certain amount of silane coupling agent modified ceramic flame retardant (CFR / MCA / APP), ethylenebis(stearoyl)amine, and curing accelerator 2, 4, 6-tris(dimethylaminomethyl)phenol (DMP-30) to the epoxy resin, and stir thoroughly under vacuum until completely blended to obtain a precursor solution.

[0031] As an epoxy resin curing accelerator, DMP-30 can reduce the curing temperature of epoxy resin, improve the mechanical strength of the material, and reduce the possibility of thermal decomposition of fillers in epoxy resin composite materials. According to the thermogravimetric analysis of fillers, ammonium polyphosphate and melamine cyanurate will undergo trace thermal decomposition above 150°C.

[0032] As a preferred embodiment of the present invention, in step 2), the content of the silane coupling agent modified ceramic flame retardant in the epoxy resin solution is 30% to 50%.

[0033] As a preferred embodiment of the present invention, in step 2), the content of ethylene bis stearylamine in the epoxy resin solution is 0.5% to 1%.

[0034] As a preferred embodiment of the present invention, in step 2), the content of 2,4,6-tris(dimethylaminomethyl)phenol is 0.5% to 5% of the epoxy resin mixture.

[0035] As a preferred embodiment of the present invention, in step 2), the vacuum environment is -1Mpa~-0.8Mpa, the stirring speed is 700r / min~900r / min, and the stirring time is 2h~2.5h.

[0036] 4) Pour the precursor solution into a specific mold, place it in a forced air drying oven for heating and curing, and obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0037] As a preferred embodiment of the present invention, in step 4, the curing conditions are 87°C~102°C for curing for 1.5h~2.5h, then the temperature is raised to 110°C~130°C for curing for 1.5h~2.5h, and the temperature is further raised to 124°C~146°C for curing for 1.5h~2.5h. The heating process during this period is 0.2h~0.5h. The addition of DMP-30 accelerates the curing and cross-linking reaction of the blending system, plays a catalytic role, and makes the curing reaction easier to proceed. The three-stage heating can improve the mechanical strength of the epoxy resin material itself.

[0038] The present invention also defines the application of the epoxy resin flame retardant composite material, which is applied to fireproof filling of building materials, fireproof filling of wires and cables, and fireproof filling of copper clad plates in the field of flame retardancy.

[0039] Example 1 The present embodiment discloses an epoxy resin highly fire-resistant and flame-retardant composite material, the raw materials of which include epoxy resin, model E51, selected from Nantong Xingchen Synthetic Materials Co., Ltd.; silane coupling agent, model KH560, selected from Kangjin New Materials Technology Co., Ltd.; methyltetrahydrophthalic anhydride, model MTHPA, selected from Guangzhou Qihua Chemical Co., Ltd.; ethylenebis(ethylenebis(ethylenebis(ethylenebis(ethylenebis(ethylenebis(ethylenebis(ethylenebis(ethylenebis(ethylene(ii(e(xylene(ii(e(e(xylene(ii(e(e(e(xylene(ii(e(e(e(xylene(ii(e(e(e(xylene(ii(e(e(e(xylene(ii(e(e(e(

[0040] The detailed preparation process is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 40 g of calcium silicate (CaSiO3), 20 g of silicon dioxide (SiO2), 20 g of calcium carbonate (CaCO3), 7 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 5 g of aluminum hydroxide (Al(OH)3), 5 g of magnesium hydroxide (Mg(OH)2), and 3 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 minutes.

[0041] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:0.4. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the temperature of the beaker to slowly drop to room temperature to obtain block-shaped ceramic flame retardant (CFR) solid particles, and then grind the block particles until there is no block solid visible to the naked eye to obtain silane-coupled ceramic flame retardant; Step S2: prepare a silane coupling agent modified ceramic flame retardant (CFR-MA), weigh 25g of melamine cyanurate (MCA) and 75g of ammonium polyphosphate (APP), dry them at 60°C for 8h, place them in a dimethyl sulfoxide solution and mix them thoroughly, then add 0.5% tridecylamine, introduce nitrogen and heat to 150°C, stir at 200rpm for 2h, cool to room temperature after the mixture is cooled, filter with ethanol twice, and then place in an oven at 60°C for 8h to dry to obtain a modified composite (MA), then mix the silane coupled ceramic flame retardant in step S1 with it in a ratio of 1:1, ball mill at 500r / min for 5min in a ball mill, and place it in a dry environment.

[0042] Step S3: Weigh 39g of epoxy resin and 31g of methyltetrahydrophthalic anhydride (MTHPA), add them to a beaker, and stir at 800r / min for 5min under a vacuum environment of -0.8MPa. After compatibility, add 30g (30% by mass) of the above-treated silane coupling agent modified ceramic flame retardant (CFR-MA), and add ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((

[0043] Step S4: pouring the above fully stirred mixture into a specific mold, pre-treating at 87° C. for 1.5 h, then heating to 110° C. for pre-curing for 1.5 h, and finally heating to 124° C. for curing for 1.5 h to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0044] Example 2 This embodiment discloses an epoxy resin highly fire-resistant and flame-retardant composite material, and the detailed preparation process thereof is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 40 g of calcium silicate (CaSiO3), 20 g of silicon dioxide (SiO2), 20 g of calcium carbonate (CaCO3), 7 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 5 g of aluminum hydroxide (Al(OH)3), 5 g of magnesium hydroxide (Mg(OH)2), and 3 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 minutes.

[0045] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:0.7. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the beaker temperature to slowly drop to room temperature to obtain block-shaped ceramic flame retardant (CFR) solid particles, and then grind the block particles until there is no block solid visible to the naked eye to obtain silane-coupled ceramic flame retardant.

[0046] Step S2: prepare a silane coupling agent modified ceramic flame retardant (CFR-MA), weigh 25g of melamine cyanurate (MCA) and 75g of ammonium polyphosphate (APP), dry them at 60°C for 8h, place them in a dimethyl sulfoxide solution and mix them thoroughly, then add 0.5% tridecylamine, introduce nitrogen and heat to 150°C, stir at 200rpm for 2h, cool to room temperature after the mixture is cooled, filter with ethanol twice, and then place in an oven at 60°C for 8h to dry to obtain a modified composite (MA), then mix the silane coupled ceramic flame retardant in step S1 with it in a ratio of 1:1, ball mill at 500r / min for 5min in a ball mill, and place it in a dry environment.

[0047] Step S3: Weigh 33g of epoxy resin and 27g of methyltetrahydrophthalic anhydride (MTHPA), add them to a beaker, and stir at 800r / min for 5min under a vacuum environment of -0.8MPa. After compatibility, add 40g (40% by mass) of the above-treated silane coupling agent modified ceramic flame retardant (CFR-MA), and add ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((

[0048] Step S4: pouring the above fully stirred mixture into a specific mold, pre-treating at 87° C. for 1.5 h, then heating to 110° C. for pre-curing for 1.5 h, and finally heating to 124° C. for curing for 1.5 h to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0049] Example 3 This embodiment discloses an epoxy resin highly fire-resistant and flame-retardant composite material, and the detailed preparation process thereof is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 40 g of calcium silicate (CaSiO3), 20 g of silicon dioxide (SiO2), 20 g of calcium carbonate (CaCO3), 7 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 5 g of aluminum hydroxide (Al(OH)3), 5 g of magnesium hydroxide (Mg(OH)2), and 3 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 minutes.

[0050] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:1. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the temperature of the beaker to slowly drop to room temperature to obtain block-shaped ceramic flame retardant (CFR) solid particles, and then grind the block particles until there is no block solid visible to the naked eye to obtain silane-coupled ceramic flame retardant.

[0051] Step S2: prepare a silane coupling agent modified ceramic flame retardant (CFR-MA), weigh 25g of melamine cyanurate (MCA) and 75g of ammonium polyphosphate (APP), dry them at 60°C for 8h, place them in a dimethyl sulfoxide solution and mix them thoroughly, then add 0.5% tridecylamine, introduce nitrogen and heat to 150°C, stir at 200rpm for 2h, cool to room temperature after the mixture is cooled, filter with ethanol twice, and then place in an oven at 60°C for 8h to dry to obtain a modified composite (MA), then mix the silane coupled ceramic flame retardant in step S1 with it in a ratio of 1:1, ball mill at 500r / min for 5min in a ball mill, and place it in a dry environment.

[0052] Step S3: Weigh 27g of epoxy resin and 23g of methyltetrahydrophthalic anhydride (MTHPA), add them to a beaker, and stir at 800r / min for 5min under a vacuum environment of -0.8MPa. After compatibility, add 50g (mass fraction 50%) of the above-treated silane coupling agent modified ceramic flame retardant (CFR-MA), and add ethylene bis(stearyl ester amine) (EBS) in proportion, and stir at 800r / min for 2h under a vacuum environment of -0.8MPa, then add 2% of 2, 4, 6-tris(dimethylaminomethyl)phenol (DMP-30), and continue stirring at 800r / min for 5min to obtain a precursor solution. The mass ratio of epoxy resin solution to ethylene bis(stearyl ester amine) (EBS) is 100:1.

[0053] Step S4: pouring the above fully stirred mixture into a specific mold, pre-treating at 87° C. for 1.5 h, then heating to 110° C. for pre-curing for 1.5 h, and finally heating to 124° C. for curing for 1.5 h to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0054] Example 4 This embodiment discloses an epoxy resin highly fire-resistant and flame-retardant composite material, and the detailed preparation process thereof is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 50 g of calcium silicate (CaSiO3), 23 g of silicon dioxide (SiO2), 15 g of calcium carbonate (CaCO3), 5 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 3 g of aluminum hydroxide (Al(OH)3), 3 g of magnesium hydroxide (Mg(OH)2), and 1 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 minutes.

[0055] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:1. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the temperature of the beaker to slowly drop to room temperature to obtain block-shaped ceramic flame retardant (CFR) solid particles, and then grind the block particles until there is no block solid visible to the naked eye to obtain silane-coupled ceramic flame retardant.

[0056] Step S2: prepare a silane coupling agent modified ceramic flame retardant (CFR-MA), weigh 25g of melamine cyanurate (MCA) and 50g of ammonium polyphosphate (APP), dry them at 60°C for 8h, place them in a dimethyl sulfoxide solution and mix them thoroughly, then add 1.5% tridecylamine, introduce nitrogen and heat to 180°C, stir at 600rpm for 3h, cool to room temperature after stirring, filter with ethanol 3 times, and then place in an oven at 60°C for 8h to dry to obtain a modified composite (MA), then mix the silane coupled ceramic flame retardant in step S1 with it in a ratio of 1:3, ball mill in a ball mill at 700r / min for 10min, and place it in a dry environment.

[0057] Step S3: Weigh 27g of epoxy resin and 23g of methyltetrahydrophthalic anhydride (MTHPA), add them to a beaker, and stir at 500r / min for 10min under a vacuum environment of -1MPa. After compatibility, add 50g (mass fraction 50%) of the above-treated silane coupling agent modified ceramic flame retardant (CFR-MA), and add ethylene bis(stearyl ester amine) (EBS) in proportion, and stir at 900r / min for 2.5h under a vacuum environment of -1MPa, then add 0.5% of 2, 4, 6-tris(dimethylaminomethyl)phenol (DMP-30), and continue stirring at 800r / min for 5min to obtain a precursor solution. The mass ratio of epoxy resin solution to ethylene bis(stearyl ester amine) (EBS) is 100:1.

[0058] Step S4: pouring the above fully stirred mixture into a specific mold, pre-treating at 102° C. for 2.5 hours, then heating to 130° C. for pre-curing for 2.5 hours, and finally heating to 146° C. for curing for 2.5 hours to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0059] Example 5 This embodiment discloses an epoxy resin highly fire-resistant and flame-retardant composite material, and the detailed preparation process thereof is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 41 g of calcium silicate (CaSiO3), 25 g of silicon dioxide (SiO2), 15 g of calcium carbonate (CaCO3), 5 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 6 g of aluminum hydroxide (Al(OH)3), 6 g of magnesium hydroxide (Mg(OH)2), and 2 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 min.

[0060] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:1. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the temperature of the beaker to slowly drop to room temperature to obtain block-shaped ceramic flame retardant (CFR) solid particles, and then grind the block particles until there is no block solid visible to the naked eye to obtain silane-coupled ceramic flame retardant.

[0061] Step S2: prepare a silane coupling agent modified ceramic flame retardant (CFR-MA), weigh 25g of melamine cyanurate (MCA) and 100g of ammonium polyphosphate (APP), dry them at 60°C for 8h, place them in a dimethyl sulfoxide solution and mix them thoroughly, then add 5% tridecylamine, introduce nitrogen and heat to 170°C, stir at 500rpm for 1h, cool to room temperature after stirring, filter with ethanol 3 times, and then place in an oven at 60°C for 8h to dry to obtain a modified composite (MA), then mix the silane coupled ceramic flame retardant in step S1 with it in a ratio of 1:2, ball mill at 700r / min for 8min in a ball mill, and place it in a dry environment.

[0062] Step S3: Weigh 27g of epoxy resin and 23g of methyltetrahydrophthalic anhydride (MTHPA), add them to a beaker, and stir at 700r / min for 8min under a vacuum environment of -0.9MPa. After compatibility, add 50g (mass fraction 50%) of the above-treated silane coupling agent modified ceramic flame retardant (CFR-MA), and add ethylene bis(stearyl)amide (EBS) in proportion, and stir at 700r / min for 2.1h under a vacuum environment of -0.9MPa, then add 5% of 2, 4, 6-tris(dimethylaminomethyl)phenol (DMP-30), and continue stirring at 800r / min for 5min to obtain a precursor solution. The mass ratio of epoxy resin solution to ethylene bis(stearyl)amide (EBS) is 100:1.

[0063] Step S4: pouring the above fully stirred mixture into a specific mold, pre-treating at 100° C. for 2 hours, then heating to 120° C. for pre-curing for 2 hours, and finally heating to 130° C. for curing for 2 hours to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0064] Comparative Example 1: This embodiment discloses an epoxy resin flame retardant composite material, and the detailed preparation process thereof is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 40 g of calcium silicate (CaSiO3), 20 g of silicon dioxide (SiO2), 20 g of calcium carbonate (CaCO3), 7 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 5 g of aluminum hydroxide (Al(OH)3), 5 g of magnesium hydroxide (Mg(OH)2), and 3 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 minutes.

[0065] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:0.4. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the temperature of the beaker to slowly drop to room temperature to obtain block-shaped solid particles of ceramic flame retardant (CFR), and then grind the block particles until there is no block solid visible to the naked eye.

[0066] Step S2: Weigh 39g of epoxy resin and 31g of methyltetrahydrophthalic anhydride (MTHPA), add them into a beaker, and stir at 800r / min for 5min under a vacuum environment of -0.8MPa. After they are compatible, add the above-treated ceramic flame retardant (CFR), and add ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((

[0067] Step S3: pouring the above fully stirred mixture into a specific mold, pre-treating at 87° C. for 1.5 h, then heating to 110° C. for pre-curing for 1.5 h, and finally heating to 124° C. for curing for 1.5 h to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0068] Comparative Example 2 This embodiment discloses an epoxy resin flame retardant composite material, and the detailed preparation process thereof is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 40 g of calcium silicate (CaSiO3), 20 g of silicon dioxide (SiO2), 20 g of calcium carbonate (CaCO3), 7 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 5 g of aluminum hydroxide (Al(OH)3), 5 g of magnesium hydroxide (Mg(OH)2), and 3 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 minutes.

[0069] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:0.7. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the temperature of the beaker to slowly drop to room temperature to obtain block-shaped ceramic flame retardant (CFR) solid particles, and then grind the block particles until there is no block solid visible to the naked eye.

[0070] Step S2: Weigh 33 parts of epoxy resin and 27g of methyltetrahydrophthalic anhydride (MTHPA), add them into a beaker, and stir at 800r / min for 5min under a vacuum environment of -0.8MPa. After compatibility, add 40g (mass fraction 40%) of the above-treated ceramic flame retardant (CFR), and add ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((

[0071] Step S3: pouring the above fully stirred mixture into a specific mold, pre-treating at 87° C. for 1.5 h, then heating to 110° C. for pre-curing for 1.5 h, and finally heating to 124° C. for curing for 1.5 h to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0072] Comparative Example 3 This embodiment discloses an epoxy resin flame retardant composite material, and the detailed preparation process thereof is as follows: Step S1: Prepare a ceramic flame retardant (CFR), weigh 40 g of calcium silicate (CaSiO3), 20 g of silicon dioxide (SiO2), 20 g of calcium carbonate (CaCO3), 7 g of hydrated zinc borate (2ZnO·3B2O3·3.5H2O), 5 g of aluminum hydroxide (Al(OH)3), 5 g of magnesium hydroxide (Mg(OH)2), and 3 g of hydrated calcium borate (2CaO·2B2O3·nH2O), slowly add them into a beaker containing anhydrous ethanol solution, and continue stirring for 5 minutes.

[0073] Then add silane coupling agent (KH560) in proportion and continue stirring for 10 minutes. The mass ratio of ceramic flame retardant (CFR) to silane coupling agent (KH560) is 100:1. After sufficient stirring, immediately put it into a blast drying oven for heat treatment at 60°C for 1 hour, and heat it to 120°C for drying. After the heat treatment, wait for the temperature of the beaker to slowly drop to room temperature to obtain block-shaped solid particles of CFR, and then grind the block particles until there is no block solid visible to the naked eye.

[0074] Step S2: Weigh 28g of epoxy resin and 22g of methyltetrahydrophthalic anhydride (MTHPA), add them to a beaker, and stir at 800r / min for 5min under a vacuum environment of -0.8MPa. After compatibility, add 50g (mass fraction 50%) of the above-treated ceramic flame retardant (CFR), and add ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis(ethylene bis((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((

[0075] Step S3: pouring the above fully stirred mixture into a specific mold, pre-treating at 87° C. for 1.5 h, then heating to 110° C. for pre-curing for 1.5 h, and finally heating to 124° C. for curing for 1.5 h to obtain a highly fire-resistant and flame-retardant epoxy resin composite material.

[0076] The limiting oxygen index (LOI) and flammability rating (UL-94) of the composite materials prepared in the examples and comparative examples were measured, as shown in Table 1; and their thermal stability was tested, as shown in FIG. 1( a ).

[0077] Table 1 Limiting oxygen index and UL-94 of composite materials of examples and comparative examples

[0078] The flame retardant properties of the EP composite materials were evaluated by LOI and UL-94 tests, and the test results are shown in Table 1. Comparative Examples 1, 2, and 3 are composite materials with only 30%, 40%, and 50% ceramic flame retardant (CFR) added by mass fraction. Among them, the limiting oxygen index (LOI) of Comparative Example 1 is 17.6%, the limiting oxygen index (LOI) of Comparative Example 2 is 19.7%, and the limiting oxygen index (LOI) of Comparative Example 3 is 25.6%. At the same time, the vertical burning rating (UL-94) of Comparative Examples 1 and 2 is no rating (NR), and only the vertical burning rating (UL-94) of Comparative Example 3 reaches V-1 level. Examples 1, 2, and 3 are composite materials with 30%, 40%, and 50% of silane coupling agent modified ceramic flame retardant (CFR-MA) added by mass fraction (ceramic flame retardant: melamine cyanurate / ammonium polyphosphate = 1:1). Compared with Comparative Examples 1, 2 and 3, the limiting oxygen index (LOI) of Examples 1, 2 and 3 are 27.3%, 32.6% and 37.8% respectively, which are all higher than the non-flammable threshold (27%), and their vertical burning grades (UL-94) are all V-0.

[0079] Figure 1 (b) is the test result of thermogravimetric analyzer (TGA). Compared with comparative examples 1, 2, and 3, the residual rates of Examples 1, 2, and 3 at 800°C are higher than those of comparative examples 1, 2, and 3, and the thermal decomposition rates at 350°C to 450°C are lower than those of comparative examples 1, 2, and 3. After 500°C, the curves of Examples 1, 2, and 3 tend to be straight lines with almost no downward trend, which fully demonstrates that the ceramic flame retardant, after being compounded with melamine cyanurate and ammonium polyphosphate, exhibits better fire resistance than the ceramic flame retardant at high temperatures.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A silane coupling agent modified ceramic flame retardant, characterized in that: Ingredients include: Ceramic flame retardant filler, silane coupling agent, modified compound and solvent, wherein: the modified compound includes melamine cyanurate and ammonium polyphosphate, the addition ratio of melamine cyanurate and ammonium polyphosphate is 1:4-1:2; the addition amount of the silane coupling agent accounts for 0.4%-1% of the mass of the ceramic flame retardant filler; the addition ratio of the modified compound to the silane coupling ceramic flame retardant is 1:3-1:

1.

2. The silane coupling agent modified ceramic flame retardant according to claim 1, characterized in that: Calculated by mass fraction, the main components of ceramic flame retardant fillers are: 40%~50% calcium silicate, 20%~25% silicon dioxide, 15%~20% calcium carbonate, 5%~10% hydrated zinc borate, 3%~6% aluminum hydroxide, 3%~6% magnesium hydroxide, and 1%~3% hydrated calcium borate.

3. The method for preparing a silane coupling agent modified ceramic flame retardant according to claim 1 or 2, characterized in that: The specific steps are as follows: The ceramic flame retardant filler and the silane coupling agent are added to the solvent, mixed and stirred until there is no obvious precipitation and no obvious floating particles on the liquid surface, and then heat treated to obtain a silane coupled ceramic flame retardant; Dissolving dried melamine cyanurate and ammonium polyphosphate in a solvent, adding a catalyst, performing a heat treatment reaction under a protective atmosphere, cooling to room temperature, filtering, and drying to obtain a modified composite; The modified composite and the silane coupling ceramic flame retardant are mixed to obtain the silane coupling agent modified ceramic flame retardant.

4. The preparation method according to claim 3, characterized in that: In the step of obtaining the silane coupled ceramic flame retardant, the heat treatment is performed at 60° C. for 1 hour, and then the temperature is raised to 120° C. for 2 hours.

5. The preparation method according to claim 3, characterized in that: In the step of obtaining the modified composite, the catalyst is tridecylamine added in an amount of 0.5% to 5%; after heating to 150° C. to 180° C. in a nitrogen environment, stirring the reaction at 200 rpm to 600 rpm for 1 h to 3 h, cooling to room temperature and filtering, and drying at 60° C. for 8 h to obtain the modified composite.

6. The preparation method according to claim 3, characterized in that: In the step of obtaining the silane coupling agent modified ceramic flame retardant, the modified composite and the silane coupling ceramic flame retardant are mixed at a rotation speed of 500 r / min to 800 rpm for 5 min to 10 min.

7. Use of a silane coupling agent modified ceramic flame retardant according to claim 1 or 2 in epoxy resin highly fire-resistant and flame-retardant composite materials.

8. An epoxy resin highly fire-resistant and flame-retardant composite material, characterized in that: The raw materials include a silane coupling agent modified ceramic flame retardant, and the silane coupling agent modified ceramic flame retardant is a silane coupling agent modified ceramic flame retardant prepared by the preparation method described in any one of claims 4 to 6.

9. The epoxy resin highly fire-resistant and flame-retardant composite material according to claim 8, characterized in that: The raw materials also include ethylene bis(stearoyl)amine, a curing accelerator, and an epoxy resin solution, wherein the content of the silane coupling agent modified ceramic flame retardant in the epoxy resin solution is 30% to 50%, the content of ethylene bis(stearoyl)amine is 0.5% to 1%, and the content of the curing accelerator is 0.5% to 5%.

10. The method for preparing the epoxy resin highly fire-resistant and flame-retardant composite material as claimed in claim 9, characterized in that: The specific steps are as follows: Mix epoxy resin and methyltetrahydrophthalic anhydride in a mass ratio of 1:0.8 to 1:0.85, and stir at a speed of 500 r / min to 800 r / min for 5 min to 10 min in a vacuum environment of -1 MPa to -0.8 MPa to obtain an epoxy resin solution; Adding a silane coupling agent-modified ceramic flame retardant, ethylenebis( ... The precursor solution is subjected to three-stage temperature-raising curing to obtain an epoxy resin highly fire-resistant and flame-retardant composite material; The three-stage temperature rise curing is as follows: the first stage curing condition is: curing at 87℃~102℃ for 1.5h~2.5h; the second stage curing condition is curing at 110℃~130℃ for 1.5h~2.5h; the third stage curing condition is curing at 124℃~146℃ for 1.5h~2.5h; the temperature rise process of each stage is 0.2h~0.5h.

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