An epoxy silicone flame-retardant ceramifiable fireproof coating and its preparation method

Abstract

The present invention relates to the technical field of coatings, and discloses an epoxy silicone flame-retardant ceramizable fireproof coating and a preparation method thereof, including 100 parts by weight of epoxy resin, 1-8 parts by weight of KH560-modified silicon carbide micropowder, 28-36 parts by weight of curing agent, 5-20 parts by weight of carboxyl-terminated phosphorus-containing polysiloxane flame retardant, and 0.4-0.8 parts by weight of defoaming agent; the phosphorus-containing polysiloxane flame retardant contains carboxyl groups, which can undergo a curing cross-linking reaction with the epoxy groups of the epoxy resin and the KH560-modified silicon carbide micropowder, enabling the epoxy resin, silicon carbide micropowder, and polysiloxane flame retardant to form a chemical bonding effect, enhancing the interfacial compatibility among the three, improving the dispersion of silicon carbide in the epoxy resin coating, and increasing the flexural strength, impact strength, limiting oxygen index, and flame retardant performance of the epoxy resin cured product.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and specifically to an epoxy silicone flame-retardant ceramizable fireproof coating and a preparation method thereof. Background Art

[0002] Silicon carbide ceramic powder has good mechanical strength, hardness, thermal conductivity and flame retardancy, and has important applications in materials such as ceramics, coatings, and rubbers, and can improve the thermal conductivity, flame retardancy and mechanical properties of materials. Improving the dispersion of silicon carbide in the material matrix is the key.

[0003] Epoxy resin has good mechanical strength, high insulation performance and excellent anti-corrosion performance, and is widely used in coatings, adhesives and other aspects. However, the thermal conductivity of epoxy resin is relatively low, which is not conducive to its practical application in high thermal conductivity and heat dissipation materials, and epoxy resin is easy to burn, which limits its practical application in the field of flame retardant and fire prevention.

[0004] Using polysiloxane polymers to modify epoxy resin is an effective method to improve its comprehensive performance. The publication number CN116023663B discloses a phosphorus and nitrogen-containing polysiloxane and its preparation method and application. The imino group and phosphorus-containing group side chains of the phosphorus and nitrogen-containing polysiloxane can improve the flame retardant performance of epoxy resin, and at the same time, the carboxyl group can participate in the resin curing reaction, thereby playing a role in toughening and flame retardancy of the epoxy resin cured product. However, this patent does not improve the thermal conductivity of epoxy resin, nor does it improve the dispersion of silicon carbide in epoxy resin. Summary of the Invention

[0005] The present invention solves the problems of poor thermal conductivity and flame retardancy of epoxy resin coatings.

[0006] Technical Solution: An epoxy silicone flame-retardant ceramizable fireproof coating, comprising 100 parts by weight of epoxy resin, 1-8 parts by weight of KH560-modified silicon carbide micropowder, 28-36 parts by weight of curing agent, 5-20 parts by weight of phosphorus-containing poly-siloxane flame retardant with terminal carboxyl group, and 0.4-0.8 parts by weight of defoaming agent.

[0007] The preparation method of the phosphorus-containing poly-siloxane flame retardant with terminal carboxyl group is as follows:

[0008] (1). Add pyromellitic dianhydride, triethylamine, and 2,6,7-trioxa-1-phosphabicyclo(2.2.2)octane-4-methanol-1-oxide (CAS No. 5301-78-0) with a molar ratio of 1:(2-2.4):(2-2.2) to a solvent, stir and react, then distill off the solvent under reduced pressure, and recrystallize the product in ethyl acetate to obtain a carboxyl flame retardant intermediate.

[0009] (2) Add dipropylene glycol terminated polysiloxane, carboxyl flame retardant intermediate, and p-toluenesulfonic acid with a molar ratio of 1:(2.2 - 2.6):(0.15 - 0.18) to the solvent, stir and react in a nitrogen atmosphere, remove the solvent by vacuum distillation, wash with acetone, and dry to obtain a phosphorus-containing polysiloxane flame retardant with carboxyl groups at both ends.

[0010] Preferably, the curing agent is 4,4-diaminodiphenyl sulfone; the defoaming agent is an organosilicon defoaming agent.

[0011] Preferably, in (1), the solvent is dichloromethane, chloroform, or tetrahydrofuran.

[0012] Preferably, in (1), the reaction is carried out under reflux condensation at 40 - 50 °C for 5 - 8 h.

[0013] Preferably, in (2), the solvent is toluene or xylene.

[0014] Preferably, in (2), the reaction is carried out at 85 - 100 °C for 18 - 24 h.

[0015] Preferably, the preparation method of KH560-modified silicon carbide micropowder is as follows: add silicon carbide micropowder to toluene, disperse it by ultrasonic, then add KH560, heat to 80 - 95 °C in a nitrogen atmosphere, react for 5 - 6 h, filter, wash with ethanol, and dry to obtain KH560-modified silicon carbide micropowder.

[0016] Preferably, the preparation method of the epoxy silicone flame-retardant ceramifiable fireproof coating is as follows: add a phosphorus-containing polysiloxane flame retardant with carboxyl groups at both ends and a defoaming agent to the epoxy resin, stir, then add KH560-modified silicon carbide micropowder and a curing agent, and mix evenly to obtain the epoxy silicone flame-retardant ceramifiable fireproof coating.

[0017] The technical effect of the present invention is that: in the present invention, pyromellitic dianhydride and 2,6,7-trioxa-1-phosphabicyclo(2.2.2)octane-4-methanol-1-oxide are subjected to acid anhydride ring-opening esterification reaction to obtain a carboxyl flame retardant intermediate, and then using p-toluenesulfonic acid as a catalyst, an esterification polymerization reaction is carried out with dipropylene glycol terminated polysiloxane, and the reaction ratio of the two is controlled to obtain a phosphorus-containing polysiloxane flame retardant with carboxyl groups at both ends.

[0018] In the present invention, a phosphorus-containing polysiloxane flame retardant with terminal carboxyl groups and KH560-modified silicon carbide micropowders are added to an epoxy resin coating. The phosphorus-containing polysiloxane flame retardant contains terminal carboxyl groups. During the high-temperature thermal curing process, its carboxyl groups can undergo curing crosslinking reactions with epoxy resin and the epoxy groups of KH560-modified silicon carbide micropowders, enabling chemical bonding among the epoxy resin, silicon carbide micropowders, and polysiloxane flame retardant, enhancing the interfacial compatibility among the three, improving the dispersion of silicon carbide in the epoxy resin coating. Silicon carbide itself has the characteristics of high strength and high modulus. When uniformly dispersed in the epoxy resin matrix, it significantly improves the mechanical strength and thermal conductivity of the cured product, having a higher thermal conductivity. The polysiloxane flame retardant contains flexible siloxane segments and has a good toughening effect. Under the synergistic effect, the flexural strength and impact strength of the epoxy resin cured product are improved.

[0019] The phosphorus-containing polysiloxane flame retardant of the present invention contains a dioxaphosphapropellane flame retardant structure and has strong char-forming properties. Combustion can cause the epoxy resin matrix to dehydrate and form a carbon layer. At the same time, the siloxane segments thermally decompose to generate inorganic silicon oxides, forming a composite carbon-silicon barrier layer with silicon carbide and the carbon layer, which can inhibit the escape of smoke, isolate oxygen, prevent dripping, and play a synergistic flame retardant role with silicon carbide, making the epoxy resin coating have a higher limiting oxygen index and better flame retardant performance. Description of the Drawings

[0020] Figure 1 It is the preparation reaction formula of the carboxyl flame retardant intermediate.

[0021] Figure 2 It is the preparation reaction formula of the phosphorus-containing polysiloxane flame retardant with terminal carboxyl groups. Detailed Embodiments

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

[0023] Example 1

[0024] (1) Add 30 mmol of pyromellitic dianhydride, 63 mmol of triethylamine, and 60 mmol of 2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-4-methanol-1-oxide to 100 mL of chloroform solvent, stir and reflux at 50°C for 5 h, distill off the solvent under reduced pressure, and recrystallize the product from ethyl acetate to obtain the carboxyl flame retardant intermediate.

[0025] (2) Add 10 mmol of bis(hydroxypropyl)-terminated polysiloxane, 24 mmol of carboxyl flame retardant intermediate, and 1.8 mmol of p-toluenesulfonic acid to 300 mL of xylene solvent. Stir at 90 °C for 18 h under a nitrogen atmosphere. Remove the solvent by vacuum distillation, wash with acetone, and dry to obtain a carboxyl-terminated phosphorus-containing polysiloxane flame retardant.

[0026] (3) Add 10 g of silicon carbide micropowder (average particle size 500 nm) to 100 mL of toluene, disperse ultrasonically, then add 0.2 g of KH560. Heat to 95 °C under a nitrogen atmosphere and react for 5 h. Filter, wash with ethanol, and dry to obtain KH560-modified silicon carbide micropowder.

[0027] (4) Add 25 g of carboxyl-terminated phosphorus-containing polysiloxane flame retardant and 3 g of organosilicon defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 5 g of KH560-modified silicon carbide micropowder and 150 g of curing agent 4,4'-diaminodiphenyl sulfone, and mix well to obtain an epoxy silicone flame-retardant ceramifiable fireproof coating.

[0028] Example 2

[0029] (1) Add 30 mmol of pyromellitic dianhydride, 72 mmol of triethylamine, and 66 mmol of 2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-4-methanol-1-oxide to 150 mL of dichloromethane solvent. Stir and reflux at 40 °C for 8 h. Remove the solvent by vacuum distillation, and recrystallize the product from ethyl acetate to obtain a carboxyl flame retardant intermediate.

[0030] (2) Add 10 mmol of bis(hydroxypropyl)-terminated polysiloxane, 26 mmol of carboxyl flame retardant intermediate, and 1.8 mmol of p-toluenesulfonic acid to 400 mL of xylene solvent. Stir at 85 °C for 24 h under a nitrogen atmosphere. Remove the solvent by vacuum distillation, wash with acetone, and dry to obtain a carboxyl-terminated phosphorus-containing polysiloxane flame retardant.

[0031] (3) Add 10 g of silicon carbide micropowder (average particle size 500 nm) to 100 mL of toluene, disperse ultrasonically, then add 0.3 g of KH560. Heat to 95 °C under a nitrogen atmosphere and react for 5 h. Filter, wash with ethanol, and dry to obtain KH560-modified silicon carbide micropowder.

[0032] (4) Add 25 g of carboxyl-terminated phosphorus-containing polysiloxane flame retardant and 4 g of organosilicon defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 25 g of KH560-modified silicon carbide micropowder and 180 g of curing agent 4,4'-diaminodiphenyl sulfone, and mix well to obtain an epoxy silicone flame-retardant ceramifiable fireproof coating.

[0033] Example 3

[0034] (1) Add 30 mmol of pyromellitic dianhydride, 60 mmol of triethylamine, and 60 mmol of 2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-4-methanol-1-oxide to 150 mL of tetrahydrofuran solvent. Stir and reflux the reaction at 40 °C for 6 h. Remove the solvent by vacuum distillation, and recrystallize the product from ethyl acetate to obtain a carboxyl flame retardant intermediate.

[0035] (2) Add 10 mmol of dihydroxypropyl-terminated polysiloxane, 22 mmol of the carboxyl flame retardant intermediate, and 1.5 mmol of p-toluenesulfonic acid to 400 mL of toluene solvent. Stir at 100 °C for 24 h under a nitrogen atmosphere. Remove the solvent by vacuum distillation, wash with acetone, and dry to obtain a phosphorus-containing polysiloxane flame retardant with carboxyl end groups.

[0036] (3) Add 10 g of silicon carbide micropowder (average particle size 500 nm) to 100 mL of toluene, disperse it by ultrasonic wave, then add 0.3 g of KH560. Heat to 80 °C in a nitrogen atmosphere and react for 6 h. Filter, wash with ethanol, and dry to obtain KH560-modified silicon carbide micropowder.

[0037] (4) Add 25 g of the phosphorus-containing polysiloxane flame retardant with carboxyl end groups, 2 g of silicone defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 40 g of KH560-modified silicon carbide micropowder and 140 g of curing agent 4,4-diaminodiphenyl sulfone, and mix well to obtain an epoxy silicone flame-retardant ceramizable fireproof coating.

[0038] Comparative Example 1

[0039] The difference between this comparative example and Example 1 is that the phosphorus-containing polysiloxane flame retardant with carboxyl end groups and KH560-modified silicon carbide micropowder are not added.

[0040] (1) Add 3 g of silicone defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix well to obtain an epoxy coating.

[0041] Comparative Example 2

[0042] The difference between this comparative example and Example 1 is that the phosphorus-containing polysiloxane flame retardant with carboxyl end groups is not added.

[0043] (1) Add 3 g of silicone defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 5 g of KH560-modified silicon carbide micropowder and 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix well to obtain an epoxy coating.

[0044] Comparative Example 3

[0045] The difference between this comparative example and Example 1 is that a dihydroxypropyl-terminated polysiloxane is used instead of the carboxyl-terminated phosphorus-containing polysiloxane flame retardant.

[0046] (1) Add 25 g of dihydroxypropyl-terminated polysiloxane and 3 g of silicone defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 5 g of KH560-modified silicon carbide micropowder and 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix well to obtain an epoxy coating.

[0047] Comparative Example 4

[0048] The difference between this comparative example and Example 1 is that KH560-modified silicon carbide micropowder is not added.

[0049] (1) Add 25 g of carboxyl-terminated phosphorus-containing polysiloxane flame retardant and 3 g of silicone defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix well to obtain an epoxy coating.

[0050] Comparative Example 5

[0051] The difference between this comparative example and Example 1 is that silicon carbide micropowder is used instead of KH560-modified silicon carbide micropowder.

[0052] (1) Add 25 g of carboxyl-terminated phosphorus-containing polysiloxane flame retardant and 3 g of silicone defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 5 g of silicon carbide micropowder and 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix well to obtain an epoxy coating.

[0053] Thermally cure the coating at 100 °C for 3 h, and then thermally cure it at 140 °C for 4 h to prepare an epoxy resin cured product.

[0054] Use an oxygen index tester to test the flame retardancy of the cured product according to the GB / T 2406.1-2008 standard.

[0055] Use a double-plate thermal conductivity tester to test the thermal conductivity of the cured product according to the GB / T 3399-1982 standard.

[0056] A universal testing machine was used to test the flexural strength and impact strength of the cured product according to GB / T 2567-2021 standard.

[0057] Table 1 Epoxy coating performance test

[0058]

[0059] As can be seen from Table 1, compared with the epoxy coating of Comparative Example 1, Examples 1-3 are added with a terminal carboxyl phosphorus-containing polysiloxane flame retardant and KH560 modified silicon carbide powder. The phosphorus-containing polysiloxane flame retardant contains a terminal carboxyl group. During the high-temperature thermal curing process, its carboxyl group can undergo a curing and cross-linking reaction with the epoxy resin and the epoxy group of the KH560 modified silicon carbide powder, so that the epoxy resin, the silicon carbide powder and the polysiloxane flame retardant form a chemical bond, thereby enhancing the interface compatibility between the three and improving the dispersibility of silicon carbide in the epoxy resin coating. Silicon carbide itself has the characteristics of high strength and high modulus, and is evenly dispersed in the epoxy resin matrix, which significantly improves the mechanical strength and thermal conductivity of the cured product and has a higher thermal conductivity coefficient. The polysiloxane flame retardant contains a flexible siloxane segment and has a good toughening effect. Under the synergistic effect, the bending strength and impact strength of the epoxy resin cured product are improved.

[0060] Phosphorus-containing polysiloxane flame retardant contains trioxaphosphabicyclo The flame retardant structure has a strong carbon-forming property. Combustion can dehydrate the epoxy resin matrix to form a carbon layer. At the same time, the polysiloxane chain segment is pyrolyzed to generate inorganic silicon oxide, which forms a composite carbon-silicon barrier layer with silicon carbide and the carbon layer. It can inhibit smoke escape, isolate oxygen, and prevent dripping. It has a synergistic flame retardant effect with silicon carbide, making the epoxy resin coating have a higher limiting oxygen index and better flame retardant properties.

[0061] Comparative Example 2 added KH560 modified silicon carbide powder. After being modified by KH560, the silicon carbide powder also had good compatibility with epoxy resin, and its bending strength and impact strength were higher than those of Comparative Example 1. However, no carboxyl-terminated phosphorus-containing polysiloxane flame retardant was added, and no flexible siloxane segment was contained, so the toughening effect was poor, and the bending strength and impact strength were lower than those of Example 1. In addition, the flame retardancy was poor, and the limiting oxygen index was low.

[0062] The dihydroxypropyl-terminated polysiloxane added in Comparative Example 3 does not contain a carboxyl group and cannot undergo a curing and crosslinking reaction with the epoxy resin and the epoxy group of the KH560 modified silicon carbide micropowder, resulting in a poor toughening effect, and the bending strength and impact strength are lower than those in Example 1. In addition, the flame retardancy is poor and the limiting oxygen index is low.

[0063] In Comparative Example 4, a phosphorus-containing carboxyl-terminated polysiloxane flame retardant was added, which had a certain toughening effect. The flexural strength and impact strength were higher than those of Comparative Example 1. However, KH550-modified silicon carbide micropowder was not added, resulting in poor strengthening effect. The flexural strength, impact strength, and limiting oxygen index were lower than those of Example 1.

[0064] In Comparative Example 5, the silicon carbide micropowder added was not modified with KH560, and its compatibility with the phosphorus-containing carboxyl-terminated polysiloxane flame retardant and epoxy resin was poor. It was not evenly dispersed in the epoxy resin matrix, and the flexural strength, impact strength, thermal conductivity, and limiting oxygen index were all lower than those of Example 1.

[0065] Example 4

[0066] The difference between this comparative example and Example 1 is that the dosage of the phosphorus-containing carboxyl-terminated polysiloxane flame retardant is.

[0067] (1) Add 50 g of phosphorus-containing carboxyl-terminated polysiloxane flame retardant, 3 g of organosilicon defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 5 g of KH560-modified silicon carbide micropowder and 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix evenly to obtain an epoxy silicone flame-retardant ceramifiable fireproof coating.

[0068] Example 5

[0069] The difference between this comparative example and Example 1 is that the dosage of the phosphorus-containing carboxyl-terminated polysiloxane flame retardant is.

[0070] (1) Add 75 g of phosphorus-containing carboxyl-terminated polysiloxane flame retardant, 3 g of organosilicon defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 5 g of KH560-modified silicon carbide micropowder and 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix evenly to obtain an epoxy silicone flame-retardant ceramifiable fireproof coating.

[0071] Example 6

[0072] The difference between this comparative example and Example 1 is that the dosage of the phosphorus-containing carboxyl-terminated polysiloxane flame retardant is.

[0073] (1) Add 100 g of phosphorus-containing carboxyl-terminated polysiloxane flame retardant, 3 g of organosilicon defoamer (Tego Foamex 842) to 500 g of epoxy resin E44. After stirring, add 5 g of KH560-modified silicon carbide micropowder and 150 g of curing agent 4,4-diaminodiphenyl sulfone, and mix evenly to obtain an epoxy silicone flame-retardant ceramifiable fireproof coating.

[0074] Table 2 Performance Test of Epoxy Silicone Flame-Retardant Ceramifiable Fireproof Coating

[0075]

[0076] As can be seen from Table 2, with the increase in the dosage of the phosphorus-containing polysiloxane flame retardant with terminal carboxyl groups, the coating still has good limiting oxygen index, flexural strength and impact strength.

[0077] The above content is only an example and illustration of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar ways to replace them. As long as they do not deviate from the invention or exceed the scope defined by this claims, they should fall within the protection scope of the present invention.

Claims

1. An epoxy silicone flame-retardant ceramizable fireproof coating, characterized in that, The epoxy silicone flame-retardant ceramizable fireproof coating is composed of the following raw materials: 100 parts by weight of epoxy resin, 1-8 parts by weight of KH560-modified silicon carbide micropowder, 28-36 parts by weight of curing agent, 5-20 parts by weight of carboxyl-terminated phosphorus-containing polysiloxane flame retardant, 0.4-0.8 parts by weight of defoamer. When cured at high temperature, a chemical bonding effect is formed among the epoxy resin, KH560-modified silicon carbide micropowder, and carboxyl-terminated phosphorus-containing polysiloxane flame retardant. The preparation method of the carboxyl-terminated phosphorus-containing polysiloxane flame retardant is as follows: (1) Add pyromellitic dianhydride, triethylamine, and 2,6,7-trioxa-1-phosphabicyclo(2.2.2)octane-4-methanol-1-oxide with a molar ratio of 1:(2-2.4):(2-2.2) to a solvent, stir and react, then perform vacuum distillation and recrystallization to obtain a carboxyl flame retardant intermediate. (2) Add a double hydroxypropyl-terminated polysiloxane, a carboxyl flame retardant intermediate, and p-toluenesulfonic acid with a molar ratio of 1:(2.2 - 2.6):(0.15 - 0.18) to a solvent, stir and react in a nitrogen atmosphere, carry out vacuum distillation, washing, and drying to obtain a phosphorus-containing polysiloxane flame retardant with carboxyl groups at both ends; the phosphorus-containing polysiloxane flame retardant contains a dioxaphosphabicyclo flame retardant structure. When burning, the polysiloxane chain segment pyrolyzes to generate inorganic silicon oxides, which form a composite carbon-silicon barrier layer with the carbon layer formed by the dehydration of KH560-modified silicon carbide micropowder and the epoxy resin matrix. The preparation method of the KH560-modified silicon carbide micropowder is as follows: Add silicon carbide micropowder to toluene, ultrasonically disperse it, then add KH560, heat to 80-95 °C in a nitrogen atmosphere, react for 5-6 h, filter, wash with ethanol, and dry to obtain KH560-modified silicon carbide micropowder.

2. The epoxy silicone flame-retardant ceramizable fireproof coating according to claim 1, wherein The curing agent is 4,4-diaminodiphenyl sulfone; the defoamer is a silicone defoamer.

3. The epoxy silicone flame-retardant ceramifiable fireproof coating according to claim 1, characterized in that, In the above (1), the solvent is dichloromethane, chloroform, or tetrahydrofuran.

4. The epoxy silicone flame-retardant ceramizable fireproof coating according to claim 1, characterized in that, In the above (1), the reaction is carried out under reflux condensation at 40-50 °C for 5-8 h.

5. The epoxy silicone flame-retardant ceramizable fireproof coating according to claim 1, wherein In the above (2), the solvent is toluene or xylene.

6. The epoxy silicone flame-retardant ceramifiable fireproof coating according to claim 1, wherein, In the above (2), the reaction is carried out at 85-100 °C for 18-24 h.

7. An epoxy silicone flame-retardant ceramifiable fireproof coating according to any one of claims 1-6, characterized in that, The preparation method of the epoxy silicone flame-retardant ceramizable fireproof coating is as follows: Add the carboxyl-terminated phosphorus-containing polysiloxane flame retardant and defoamer to the epoxy resin, stir, then add the KH560-modified silicon carbide micropowder and curing agent, and mix evenly to obtain the epoxy silicone flame-retardant ceramizable fireproof coating.

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