Porcelainized intumescent fireproof heat-insulating coating and preparation method thereof

Abstract

The invention discloses a porcelainized expansion type fireproof heat-insulating coating and a preparation method thereof, and relates to the technical field of fire prevention, and the fireproof heat-insulating coating comprises an inner coating and an outer coating; the preparation method comprises the following steps: S1, weighing the raw materials of the component A and the component B; s2, preparing the component A; s3, preparing a component B; s4, the surface of the steel structure is coated with the component A, and an inner coating of the fireproof heat-insulating coating is obtained after normal-temperature drying; and continuously coating the surface of the dried inner coating with the component B through a spraying or brushing method, and drying at normal temperature to obtain the ceramifiable expansive fireproof heat-insulating coating. A porcelainized reaction and an intumescent flame-retardant system are combined to protect the steel structure material from two aspects of efficient flame retardance and high-temperature heat insulation, and the effect is excellent; a nitrogen-phosphorus synergistic flame retardant is used for actively inhibiting the flame combustion process, a high-temperature expansion layer formed by expansible graphite and a vitrifiable heat insulation layer formed by ceramic forming filler are used for greatly improving the high-temperature stability and heat insulation efficiency of a carbon layer, and the fire endurance of a steel structure is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of fire protection, and in particular to a ceramicizable intumescent fireproof and heat-insulating coating and a preparation method thereof. Background Art

[0002] With the development of industrial technology, the demand for high temperature resistant and fireproof materials is increasing. Steel structures have the advantages of high strength, easy forming, low cost and environmental protection, and are widely used in offshore construction platforms, bridges, buildings and other fields. Although structural steel is a non-combustible material, it has the disadvantage of not being resistant to high temperatures. At 450-580℃, the mechanical properties of the steel structure drop significantly, and the bearing capacity is significantly reduced. Under the high temperature of the fire scene (about 800-1000℃), the exposed steel structure quickly undergoes plastic deformation and collapses within about 15 minutes, causing great economic losses and casualties. Applying fire retardant coatings on the surface of steel structures to improve their fire resistance limit can increase fire rescue time and thus reduce casualties.

[0003] Intumescent fire retardant coatings are environmentally friendly and highly efficient, and have positive significance for the thermal protection of steel structures. Traditional fire retardant coatings often use halogen flame retardants, which are prone to produce smoke and toxic gases, and most fire retardant coatings may soften and fall off under high and low temperature conditions, making it difficult to obtain good thermal insulation performance, and thus unable to effectively suppress the spread of fire. In addition, although the commercially available ultra-thin steel structure fire retardant coatings have a large expansion ratio and a good foaming effect, the number of honeycomb pores in the charcoal layer formed when encountering fire is small and the pore size is too large. In addition, the strength of the charcoal layer is often low, and the thermal stability is poor under high temperature baking. It is easy to decompose and crack, propagate cracks, and even the fireproof effect and flame retardant and smoke suppression effect are not good for a long time. According to the shortcomings of the prior art, in order to solve the problems of low flame retardant efficiency, poor thermal insulation, easy cracking at high temperature, and inability to provide long-term fire protection of traditional coatings, it is urgent to develop an ultra-thin fire retardant coating material with high flame retardant efficiency and long thermal insulation time. Summary of the invention

[0004] The purpose of the present invention is to design a ceramic expandable fireproof and heat-insulating coating and a preparation method thereof in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions: The ceramic expandable fireproof and heat-insulating coating comprises an inner coating and an outer coating, wherein the inner coating is located between the outer coating and the surface of the steel structure, and the thickness ratio of the inner coating to the outer coating is in the range of 7:3-5:5. The inner coating is composed of component A, and the outer coating is composed of component B. Component A comprises the following raw materials: epoxy resin, phosphorus-containing silicone flame retardant, expandable flame retardant, expandable graphite, dispersant, pigment filler, first curing agent and diluent; component B comprises the following raw materials: modified epoxy resin, ceramic filler, flux, second curing agent and filler additive.

[0006] A method for preparing a ceramicizable intumescent fireproof and heat-insulating coating comprises: S1. Weigh the raw materials of components A and B; S2. Preparation of component A: crush the intumescent flame retardant, expandable graphite and pigment filler by an airflow superfine pulverizer to obtain a uniformly mixed solid powder, then add epoxy resin, phosphorus-containing silicone flame retardant, dispersant and diluent, stir for 30-60 minutes to obtain a mixed coating A; add the first curing agent to the mixed coating A, continue stirring for 10-20 minutes to obtain component A; S3, preparation of component B: mixing and stirring the modified epoxy resin, the ceramic filler, the flux and the filler additive for 30-60 minutes to obtain a mixed coating B; adding the second curing agent to the mixed coating B, and continuing to stir for 10-20 minutes to obtain component B; S4. Preparation of ceramic-type intumescent fireproof and heat-insulating coating: Apply component A to the surface of steel structure, and dry at room temperature to obtain the inner coating of fireproof and heat-insulating coating; Apply component B to the surface of the dried inner coating by spraying or brushing, and dry at room temperature to obtain the ceramic-type intumescent fireproof and heat-insulating coating as mentioned above.

[0007] The beneficial effects of the present invention are as follows: combining the ceramicizable reaction and the expansion flame retardant system to protect the steel structure material from the two aspects of high-efficiency flame retardancy and high-temperature thermal insulation, with excellent effects; utilizing the nitrogen-phosphorus synergistic flame retardant to actively suppress the flame combustion process, while using the high-temperature expansion layer formed by expandable graphite and the ceramicizable thermal insulation layer formed by the ceramic filler to greatly improve the high-temperature stability and thermal insulation efficiency of the carbon layer, thereby extending the fire resistance limit of the steel structure. The prepared phosphorus-containing silicone flame retardant also improves the adhesion of the epoxy-based inner coating, overcoming the problem of high-temperature shedding of the coating. By optimizing the matching of the expansion layer and the thermal insulation filler, strengthening the adhesion of the coating to the steel substrate, and improving the strength of the expansion layer, an expansion-type fireproof and thermal insulation coating with high fire resistance, environmental protection and safety is obtained, which can be used for steel structure materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is the reaction formula of phosphorus-containing silicone flame retardant. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0010] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0011] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0012] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0013] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0014] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0015] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0016] The ceramic expandable fireproof and heat-insulating coating comprises an inner coating and an outer coating, wherein the inner coating is located between the outer coating and the surface of the steel structure, and the thickness ratio of the inner coating to the outer coating is in the range of 7:3-5:5. The inner coating is composed of component A, and the outer coating is composed of component B. Component A comprises the following raw materials: epoxy resin, phosphorus-containing silicone flame retardant, expandable flame retardant, expandable graphite, dispersant, pigment filler, first curing agent and diluent; component B comprises the following raw materials: modified epoxy resin, ceramic filler, flux, second curing agent and filler additive.

[0017] The raw materials of component A are as follows by weight: 40-70 parts of epoxy resin, 20-50 parts of phosphorus-containing silicone flame retardant, 20-40 parts of expansion flame retardant, 5-20 parts of expandable graphite, 1-10 parts of dispersant, 3-15 parts of color filler, 65-100 parts of first curing agent and 5-20 parts of diluent.

[0018] The raw materials of component B are as follows by weight: 45-80 parts of modified epoxy resin, 10-40 parts of ceramic filler, 5-11 parts of flux, 20-40 parts of second curing agent and 3-15 parts of filler auxiliary agent.

[0019] The epoxy resin is a low-viscosity epoxy resin with a solid content of 99% and a viscosity (at room temperature 25°C) of 300-2000 mPa.s. It is preferably a mixture of one or more of Baling Petrochemical Epoxy Resin CYD115 or Epoxy Resin CYDW100 in any proportion.

[0020] The phosphorus-containing organic silicon flame retardant is prepared from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and γ-aminopropyltrimethoxysilane KH560, and the reaction formula is as follows: Figure 1 As shown, the reaction temperature is 160-180°C and the reaction time is 6-8h.

[0021] The mass ratio of dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and γ-aminopropyltrimethoxysilane KH560 is 1:1-1:1.3.

[0022] The intumescent flame retardant is composed of a carbonizing agent, a foaming agent and a dehydrating agent in a mass ratio of (0.5-1.0): (2.0-4.0): (1.0-2.5), and the mass ratio of the carbonizing agent, the foaming agent and the dehydrating agent is 0.5-1.0: 2.0-4.0: 1.0-2.5.

[0023] The carbonizing agent is at least one of dipentaerythritol, borophenol and dextrin; the foaming agent is at least one of urea, melamine, boric acid melamine and dicyandiamide; and the dehydrating agent is at least one of piperazine pyrophosphate, melamine phosphate and diammonium phosphate.

[0024] Expandable graphite is 325-1000 mesh flake powder with a thickness of 10-20 microns.

[0025] The dispersant is at least one of E9289, BYK-151, BD-109 and BYK-1165.

[0026] The pigment and filler is at least one of nano titanium dioxide, zinc oxide, aluminum oxide, light calcium carbonate, feldspar powder, mica powder and talc powder.

[0027] The first curing agent is an epoxy curing agent, preferably Baling Petrochemical curing agent CYDHD-253.

[0028] The diluent is an alkyl glycidyl ether, preferably C12-14 alkyl glycidyl ether, which is a colorless transparent liquid with low toxicity, no irritating odor, good flexibility, low volatility, good viscosity reduction ability for general epoxy resins, and high wettability for non-polar surfaces.

[0029] The thickness of the inner coating is 0.5-1mm, the thickness of the outer coating is 0.3-1mm, and the total thickness of the fireproof and heat-insulating coating is 1-2mm.

[0030] The modified epoxy resin is a silicone-modified epoxy resin.

[0031] The ceramic filler is at least one of zirconium phosphate with a lamellar structure, basalt flakes, magnesium hydroxide, aluminum hydroxide and low-melting-point glass powder.

[0032] The flux is glass powder, at least one of zinc borate, zinc oxide and boron oxide, and the initial melting point of the glass powder is 450-550°C.

[0033] The second curing agent is a polyamide curing agent, preferably polyamide 650.

[0034] The filler auxiliary agent is at least one of hollow glass microspheres, silica aerogel, aluminum silicate fibers and wollastonite long fibers, and the aspect ratio of the fibers is 8:1-9:1.

[0035] A method for preparing a ceramicizable intumescent fireproof and heat-insulating coating comprises: S1. Weigh the raw materials of components A and B; S2. Preparation of component A: crush the intumescent flame retardant, expandable graphite and pigment filler by an airflow superfine pulverizer to obtain a uniformly mixed solid powder, then add epoxy resin, phosphorus-containing silicone flame retardant, dispersant and diluent, and stir for 30-60 minutes using a high-speed disperser to obtain a mixed coating A; add the first curing agent to the mixed coating A, continue stirring for 10-20 minutes, and obtain component A; S3, preparation of component B: adding modified epoxy resin, porcelain-forming filler, flux and filler additive into a high-speed disperser and stirring for 30-60 minutes to obtain a mixed coating B; adding the second curing agent into the mixed coating B, and continuing to stir for 10-20 minutes to obtain component B; S4. Preparation of porcelain-type intumescent fireproof and heat-insulating coating: Apply component A to the surface of the steel structure, and dry it at room temperature for 6-12 hours to obtain the inner coating of the fireproof and heat-insulating coating; Continue to apply component B to the surface of the dried inner coating by spraying or brushing, and dry it at room temperature for 8-12 hours to obtain the porcelain-type intumescent fireproof and heat-insulating coating as mentioned above.

[0036] Embodiment 1: The ceramic intumescent fireproof and heat-insulating coating of this embodiment includes component A and component B, wherein component A is made of the following raw materials in parts by weight: 50 parts of CYDW100 epoxy resin, 20 parts of phosphorus-containing silicone flame retardant DK, 20 parts of intumescent flame retardant, 5 parts of expandable graphite, 1 part of BYK-194 dispersant, 3 parts of nano titanium dioxide, 75 parts of Baling Petrochemical CYDHD-253 curing agent, and 5 parts of diluent C12-14 alkyl glycidyl ether.

[0037] In this embodiment, the intumescent flame retardant comprises the following raw materials in parts by weight: 5 parts of piperazine pyrophosphate, 5 parts of dipentaerythritol, and 10 parts of melamine borate.

[0038] The B component is made of the following raw materials in parts by weight: 60 parts of organosilicon-modified epoxy resin, 20 parts of porcelain-forming filler, 5 parts of glass powder, 25 parts of polyamide 650 curing agent B, and 10 parts of wollastonite long fiber.

[0039] In this embodiment, the ceramic filler comprises zirconium phosphate with a flaky structure and basalt flakes, and the mass ratio of zirconium phosphate to basalt is 1:1.

[0040] The preparation method of the ceramicizable intumescent fireproof and heat-insulating coating in this embodiment comprises the following steps: S1. Weigh the raw materials of components A and B according to the ratio; S2, grinding piperazine pyrophosphate, dipentaerythritol, boric acid melamine, expandable graphite and nano titanium dioxide, and crushing them in an airflow superfine grinder to obtain a solid mixed powder; then adding epoxy resin CYDW100, phosphorus-containing silicone flame retardant DK, dispersant BYK-194 and C12-14 alkyl glycidyl ether diluent and mixing them evenly, and stirring for 40 minutes using a high-speed disperser; then adding curing agent CYDHD-253 to the above mixed coating, and continuing to stir for 20 minutes to obtain component A; S3, the silicone modified epoxy resin, zirconium phosphate, basalt flakes, glass powder and wollastonite long fibers were uniformly stirred, using a high-speed disperser for 45min; then the curing agent polyamide 650 was added to the mixed coating in proportion, stirred for 20min, to obtain component B; S4. Apply component A to the surface of the steel structure once or multiple times by spraying or brushing, and obtain the inner coating of the fireproof and heat-insulating coating after drying at room temperature for 12 hours; then apply component B to the surface of the dried inner coating by spraying or brushing, and obtain the porcelain-based high-temperature resistant fireproof and heat-insulating coating after drying at room temperature for 8 hours, wherein the inner coating has a thickness of 0.5 mm, the outer coating has a thickness of 0.5 mm, and the total thickness of the porcelain-based intumescent fireproof and heat-insulating coating is 1 mm.

[0041] Embodiment 2: The ceramic intumescent fireproof and heat-insulating coating of this embodiment includes component A and component B, wherein component A is made of the following raw materials in parts by weight: 65 parts of CYDW100 epoxy resin, 35 parts of phosphorus-containing silicone flame retardant DK, 23 parts of intumescent flame retardant, 10 parts of expandable graphite, 1 part of BYK-194 dispersant, 5 parts of nano titanium dioxide, 85 parts of Baling Petrochemical CYDHD-253 curing agent, and 8 parts of diluent C12-14 alkyl glycidyl ether.

[0042] In this embodiment, the intumescent flame retardant comprises the following raw materials in parts by weight: 10 parts of diammonium phosphate, 5 parts of dipentaerythritol, and 8 parts of melamine borate.

[0043] The B component is made of the following raw materials in parts by weight: 60 parts of organosilicon-modified epoxy resin, 30 parts of porcelain-forming filler, 8 parts of glass powder, 28 parts of polyamide 650 curing agent B, and 5 parts of wollastonite long fiber.

[0044] In this embodiment, the ceramic filler comprises zirconium phosphate with a flaky structure and basalt flakes, and the mass ratio of zirconium phosphate to basalt is 1:1.

[0045] The preparation method of the ceramicizable intumescent fireproof and heat-insulating coating in this embodiment comprises the following steps: S1. Weigh the raw materials of components A and B according to the ratio; S2, grinding ammonium dihydrogen phosphate, dipentaerythritol, boric acid melamine, expandable graphite and nano titanium dioxide, and crushing them in an airflow superfine grinder to obtain a solid mixed powder; then adding epoxy resin CYDW100, phosphorus-containing silicone flame retardant DK, dispersant BYK-194 and C12-14 alkyl glycidyl ether diluent and mixing them evenly, and stirring them for 40 minutes using a high-speed disperser; then adding curing agent CYDHD-253 to the above mixed coating, and continuing to stir for 20 minutes to obtain component A; S3, the silicone modified epoxy resin, zirconium phosphate, basalt flakes, glass powder and wollastonite long fibers were uniformly stirred, and stirred for 45 minutes using a high-speed disperser; after stirring, the curing agent polyamide 650 was added to the mixed coating in proportion, and stirring was continued for 20 minutes to obtain component B; S4. Apply component A to the surface of the steel structure once or multiple times by spraying or brushing, and obtain the inner coating of the fireproof and heat-insulating coating after drying at room temperature for 12 hours; then apply component B to the surface of the dried inner coating by spraying or brushing, and obtain the porcelain-based high-temperature resistant fireproof and heat-insulating coating after drying at room temperature for 8 hours, wherein the inner coating has a thickness of 0.5 mm, the outer coating has a thickness of 0.5 mm, and the total thickness of the porcelain-based intumescent fireproof and heat-insulating coating is 1 mm.

[0046] Embodiment 3: The only difference between this embodiment and embodiment 2 is that the inner coating thickness of the fireproof and heat-insulating coating in this embodiment is 0.7 mm, the outer coating thickness is 0.3 mm, and the total thickness of the ceramicizable intumescent fireproof and heat-insulating coating is 1 mm.

[0047] Embodiment 4: The only difference between this embodiment and embodiment 2 is that the inner coating thickness of the fireproof and heat-insulating coating in this embodiment is 1 mm, the outer coating thickness is 1 mm, and the total thickness of the ceramicizable intumescent fireproof and heat-insulating coating is 2 mm.

[0048] test In order to verify the fireproof performance of the present invention, the large plate combustion method was used to test the fireproof and heat-insulating performance of the coating material. The specific steps were as follows: coating Examples 1-4 on a steel plate, using a butane spray gun (flame temperature of about 1300°C) to burn the front side, attaching a thermocouple to the back of the steel plate, recording the back temperature of the steel plate at different times, and comparing and observing the expansion of the carbon layer. The test results are shown in Table 1.

[0049] Table 1 Performance test results of Examples 1-4

[0050] The test results show that the ceramic expandable fireproof and heat-insulating coating provided by the embodiment of the present invention has excellent fireproof and heat-insulating properties. The carbon layer formed after the coating expands is dense and complete, and the expansion multiple is high. The coating has good adhesion, no shedding phenomenon at high temperature, good heat-insulating effect, can effectively isolate the transfer of heat to the substrate, and greatly reduce the surface temperature of the steel structure.

[0051] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. Ceramizable intumescent fireproof and heat-insulating coating, characterized in that: It includes an inner coating and an outer coating. The inner coating is located between the outer coating and the surface of the steel structure. The thickness ratio of the inner coating to the outer coating is in the range of 7:3-5:

5. The inner coating is composed of component A and the outer coating is composed of component B. Component A includes the following raw materials: epoxy resin, phosphorus-containing silicone flame retardant, expansion flame retardant, expandable graphite, dispersant, color filler, first curing agent and diluent; component B includes the following raw materials: modified epoxy resin, ceramic filler, flux, second curing agent and filler additive.

2. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 1, characterized in that: The raw materials of component A are as follows by weight: 40-70 parts of epoxy resin, 20-50 parts of phosphorus-containing silicone flame retardant, 20-40 parts of expansion flame retardant, 5-20 parts of expandable graphite, 1-10 parts of dispersant, 3-15 parts of color filler, 65-100 parts of first curing agent and 5-20 parts of diluent.

3. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 1, characterized in that: The raw materials of component B are as follows by weight: 45-80 parts of modified epoxy resin, 10-40 parts of ceramic filler, 5-11 parts of flux, 20-40 parts of second curing agent and 3-15 parts of filler auxiliary agent.

4. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 1, characterized in that: The phosphorus-containing organic silicon flame retardant is prepared from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and gamma-aminopropyltrimethoxysilane KH560, with a reaction temperature of 160-180° C. and a reaction time of 6-8 hours.

5. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 3, characterized in that: The mass ratio of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and γ-aminopropyltrimethoxysilane KH560 is 1:1-1:1.

3.

6. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 1, characterized in that: The intumescent flame retardant is composed of a charring agent, a foaming agent and a dehydrating agent in a mass ratio of (0.5-1.0): (2.0-4.0): (1.0-2.5), and the mass ratio of the charring agent, the foaming agent and the dehydrating agent is 0.5~1.0:2.0~4.0:1.0~2.

5.

7. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 1, characterized in that: The thickness of the inner coating is 0.5-1mm, the thickness of the outer coating is 0.3-1mm, and the total thickness of the fireproof and heat-insulating coating is 1-2mm.

8. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 1, characterized in that: The ceramic filler is at least one of lamellar zirconium phosphate, basalt flakes, magnesium hydroxide, aluminum hydroxide and low-melting glass powder; the color filler is at least one of nano titanium dioxide, zinc oxide, aluminum oxide, light calcium carbonate, feldspar powder, mica powder and talcum powder.

9. The ceramicizable intumescent fireproof and heat-insulating coating according to claim 6, characterized in that: The carbon-forming agent is at least one of dipentaerythritol, borophenolic acid and dextrin; the foaming agent is at least one of urea, melamine, melamine borate and dicyandiamide; the dehydrating agent is at least one of piperazine pyrophosphate, melamine phosphate and diammonium phosphate; the fluxing agent is at least one of glass powder, zinc borate, zinc oxide and boron oxide; the filler auxiliary agent is at least one of hollow glass microspheres, silica aerogel, aluminum silicate fiber and wollastonite long fiber.

10. A method for preparing a ceramic intumescent fireproof and heat-insulating coating, characterized in that: include: S1. Weigh the raw materials of components A and B; S2. Preparation of component A: crush the intumescent flame retardant, expandable graphite and pigment filler by an airflow superfine pulverizer to obtain a uniformly mixed solid powder, then add epoxy resin, phosphorus-containing silicone flame retardant, dispersant and diluent, stir for 30-60 minutes to obtain a mixed coating A; add the first curing agent to the mixed coating A, continue stirring for 10-20 minutes to obtain component A; S3, preparation of component B: mixing and stirring the modified epoxy resin, the ceramic filler, the flux and the filler additive for 30-60 minutes to obtain a mixed coating B; adding the second curing agent to the mixed coating B, and continuing to stir for 10-20 minutes to obtain component B; S4. Preparation of a porcelain-type intumescent fireproof and heat-insulating coating: Apply component A to the surface of a steel structure, and dry it at room temperature to obtain an inner coating of the fireproof and heat-insulating coating; Continue to apply component B to the surface of the dried inner coating by spraying or brushing, and dry it at room temperature to obtain a porcelain-type intumescent fireproof and heat-insulating coating as described in any one of claims 1 to 9.

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