Fire-resistant and pressure-resistant coating and preparation method thereof

Abstract

The present invention relates to the field of fire-retardant coating preparation, specifically to a fire-retardant and pressure-resistant coating. The coating raw materials include 36-66 parts of a film-forming substance, 7-12 parts of silica aerogel powder, 8-15 parts of multilayer graphene oxide, 15-25 parts of hollow ceramic microspheres, and 2-4 parts of an additive. A method for preparing the fire-retardant and pressure-resistant coating is also disclosed. The present invention has the beneficial effects of having excellent Class A fireproofing performance, strong compressive strength, outstanding thermal insulation properties, and strong weather resistance and chemical corrosion resistance. This coating can provide excellent waterproofing and pressure resistance for equipment, facilities, and buildings in industrial, civilian, and military fields.

Description

Technical Field

[0001] The present invention relates to a fireproof and pressure-resistant coating and a preparation method thereof, which is applicable to the fireproofing and pressure-resistant requirements of equipment, facilities and buildings in industrial, civil and military fields. Background Art

[0002] Fire retardant coatings, as an effective material for preventing the spread of fire in storage tanks, other equipment, facilities, and buildings, have attracted widespread attention in recent years. Currently, fire retardant coatings are divided into intumescent and non-intumescent types. Intumescent fire retardant coatings primarily contain melamine, ammonium polyphosphate, and pentaerythritol, but melamine is harmful to the human body. Non-intumescent fire retardant coatings often require a thickness of 2-3 cm to meet fire protection requirements, and their weight exceeds the pressure-bearing capacity of many equipment. Furthermore, non-intumescent fire retardant coatings are complex to apply and are prone to cracking.

[0003] To overcome these issues, the present invention discloses a fire-retardant and pressure-resistant coating formulation and preparation method. This coating offers significant fireproofing, resistance to open flames, and excellent thermal insulation. It also exhibits excellent compressive and ductile properties, resulting in a long service life and wide applicability to various storage tanks, buildings, and military equipment surfaces. Furthermore, the coating formulation contains no organic solvents and no harmful volatile gases such as benzene and formaldehyde, making it both human-friendly and environmentally friendly. Summary of the Invention

[0004] In order to solve the problems in the background technology and achieve good fire resistance and pressure resistance, the present invention provides a fire retardant and pressure resistant coating and a preparation method thereof.

[0005] A technical solution adopted by the present invention to solve its technical problem is:

[0006] 36-66 parts of film-forming substance, 7-12 parts of silica aerogel powder, 8-15 parts of multilayer graphene oxide, 15-25 parts of hollow ceramic microspheres, and 2-4 parts of auxiliary agent.

[0007] Furthermore, the film-forming substance is a two-component substance, wherein component A is 2,4'-diphenylmethane diisocyanate and component B is diethyltoluenediamine, and the mass ratio is 1:1.

[0008] Furthermore, the auxiliary agent is a dispersant, a defoaming agent and a leveling agent.

[0009] Furthermore, the number of layers of multi-layer graphene oxide in the fire-retardant and pressure-resistant coating is 5-10, and the size is 1000-2000 nanometers.

[0010] The main benefits of using multilayer graphene oxide include three aspects: 1. First, the graphene oxide surface retains some functional groups (including hydroxyl, carboxyl, and carbonyl groups), which makes it more soluble in polar film-forming materials and allows for uniform dispersion. At the same time, it also retains some of the graphene's π electrons, allowing them to form Si-C bonds with defects on the surface of the silica aerogel powder, thereby achieving good solubility and dispersibility of the silica aerogel powder in the film-forming material. 2. In addition, multilayer graphene oxide has a well-defined layered structure. This structure can form gaps when exposed to open flames or high temperatures, thus forming a carbon framework structure, which maintains the integrity of the coating while also being more conducive to heat insulation. 3. Finally, when exposed to high temperatures or open flames, the surface functional groups of graphene oxide will break and release CO2 gas, isolating it from the air and playing an important role in supporting combustion. If the number of graphene oxide layers is too small, the carbon framework structure and thermal insulation effect cannot be well maintained. If the number of layers is too large, the properties of the two-dimensional material will be lost, and the π electron bonding ability will be lost. The size of graphene oxide is determined by cost-effectiveness and its ability to bond with silica aerogel powder. Too small graphene oxide flakes have too few surface functional groups, hindering their bonding with silica. Oversized graphene oxide flakes, on the other hand, have poor solubility and dispersion in the system. Graphene oxide was purchased from Dazhan Nano (Guangdong) Co., Ltd.

[0011] Furthermore, the size of the silica aerogel powder in the fire-retardant and pressure-resistant coating is 50-200 nanometers. Silica aerogel powder has good fireproofing and heat-insulating properties, but it is hydrophobic, making it difficult to dissolve in the film-forming material. Instead, it will float in a mass on the surface of the film-forming liquid, and the smaller the size, the more obvious its hydrophobicity. Although smaller-sized aerogel powder is more beneficial to the overall fireproofing and heat-insulating properties of the coating, because the good solubility of silica aerogel powder in the film-forming material depends on it forming chemical bonds with the multilayer graphene oxide sheets, its size needs to match the size of the multilayer graphene oxide sheets, and 50-200 nanometers is the optimal size. Too small or too small is not conducive to forming a reasonable bond with the multilayer graphene oxide. Too small a size will lead to an increase in the amount of multilayer graphene oxide added, while too large a size will make it difficult to dissolve in the film-forming material even if multilayer graphene oxide is present. The silica aerogel powder was purchased from Zhejiang Nano Nano Technology Co., Ltd.

[0012] Furthermore, the hollow ceramic microspheres in the fire-retardant and pressure-resistant coating range in size from 50 to 200 nanometers. The size of the hollow ceramic microspheres is closely related to their thermal insulation effectiveness. Larger hollow ceramic microspheres have a larger hollow portion, which is larger than the mean free path of air molecules, resulting in more pronounced molecular collisions and faster heat transfer. However, smaller hollow ceramic microspheres are very expensive, hindering market promotion and large-scale application. The hollow ceramic microspheres were purchased from Changzhou Honghuisheng Nanomaterials Technology Co., Ltd.

[0013] Furthermore, the fire-retardant and pressure-resistant coating is prepared as follows: a dispersant and multilayer graphene oxide are added to component B, stirred at 800 rpm for 10 minutes, then silica aerogel powder and hollow ceramic microspheres are added, stirred at 800 rpm for 15 minutes, and finally a defoamer and leveling agent are added, stirred at 500 rpm for 5 minutes to obtain a component B mixture.

[0014] Furthermore, the fire-retardant and pressure-resistant coating is constructed using spraying equipment, and the mixture of components A and B is heated to 70°C before construction. When components A and B are sprayed out of the nozzle and come into contact, components A and B react and solidify into a film on the surface of the coating equipment.

[0015] The beneficial effects of the present invention are:

[0016] (1) Multilayer graphene oxide acts as a dispersant for silica aerogel powder and a heat-insulating filler in case of fire, achieving an unexpected effect. The layered structure of graphene oxide becomes a natural heat-resistant barrier when encountering open flames (the graphene layered structure forms a framework structure after further carbonization at high temperature, and air is retained between the layers, which significantly inhibits the transfer of heat); and the aerogel powder and hollow ceramic microbeads interspersed in the graphene oxide layered structure further play a role in heat insulation and fire prevention, achieving a synergistic effect of fire prevention ability. If graphene oxide is not added, its heat insulation and fire prevention effect will be significantly reduced. The aerogel powder and hollow ceramic microbeads attached to the layered structure of graphene oxide can avoid the risk of collapse of the layered structure of graphene oxide when encountering open flames. Therefore, the combination of the three gives the coating better fire resistance, which is complementary and synergistic. The number of graphene oxide layers and the size of aerogel powder and hollow ceramic microspheres are decisive for the above-mentioned synergistic effect. The number of graphene oxide layers is related to the formation of the carbonized framework structure, while the size of aerogel powder and hollow ceramic microspheres determines their loading in the graphene oxide layered structure, which in turn affects the flame impact resistance of the graphene oxide framework structure under open flame conditions. (2) The coating has fireproof, heat-insulating and pressure-resistant effects at the same time, avoiding the need to repeatedly apply different coatings on the surface of the equipment and avoiding the consideration of the repellency between different coatings and the differences in construction processes; (3) Nano-aerogel powder and hollow ceramic particles of appropriate size are used as thermal insulation fillers to improve the thermal insulation performance of the coating when encountering open flames; (4) The coating has a long service life and does not contain volatile organic gases, which is friendly to the human body and the environment. DETAILED DESCRIPTION

[0017] The present invention will now be further described with reference to specific examples, which are intended to illustrate the present invention rather than to further limit the present invention. The auxiliary agents not specifically defined are conventional in the art and have negligible effects on the results.

[0018] Example 1

[0019] 10 grams of dispersant and 120 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 100 grams of silica aerogel powder and 200 grams of hollow ceramic microbeads were added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1000-1500 nanometers and a thickness of 5-10 layers; the silica aerogel powder had a size of 100 nanometers; and the nano-hollow ceramic had a size of 100 nanometers.

[0020] Heat 250 grams of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B after the above treatment to 70°C respectively, and use spraying equipment to spray components A and B onto the surface of the steel plate. Heat components A and B to 70°C before construction. When components A and B are sprayed out of the nozzle and come into contact, components A and B react and solidify into a film on the surface of the steel plate. The spraying thickness is 1 cm.

[0021] Comparative Example 1

[0022] Based on the fireproof and pressure-resistant coating of Example 1, the A component (2,4'-diphenylmethane diisocyanate) and the original B component (diethyltoluenediamine) were both changed to 160 grams, and other conditions remained unchanged.

[0023] Comparative Example 2

[0024] Based on the fireproof and pressure-resistant coating of Example 1, the amount of component A (2,4'-diphenylmethane diisocyanate) and the original component B (diethyltoluenediamine) were both changed to 350 grams, while other conditions remained unchanged.

[0025] Comparative Example 3

[0026] Based on the fireproof and pressure-resistant coating of Example 1, the amount of silica aerogel powder was changed to 60 grams, while other conditions remained unchanged.

[0027] Comparative Example 4

[0028] Based on the fire-retardant and pressure-resistant coating of Example 1, the amount of silica aerogel powder was changed to 140 grams, while other conditions remained unchanged.

[0029] Comparative Example 5

[0030] Based on the fire-retardant and pressure-resistant coating of Example 1, the amount of multilayer graphene oxide was changed to 70 grams, while other conditions remained unchanged.

[0031] Comparative Example 6

[0032] Based on the fire-retardant and pressure-resistant coating of Example 1, the amount of multilayer graphene oxide was changed to 160 grams, while other conditions remained unchanged.

[0033] Comparative Example 7

[0034] Based on the fireproof and pressure-resistant coating of Example 1, the amount of nano hollow ceramics was changed to 130 grams, while other conditions remained unchanged.

[0035] Comparative Example 8

[0036] Based on the fireproof and pressure-resistant coating of Example 1, the amount of nano hollow ceramics was changed to 270 grams, while other conditions remained unchanged.

[0037] Comparative Example 9

[0038] Based on the fire-retardant and pressure-resistant coating of Example 1, the average size of the multilayer graphene oxide was changed to <1000 nm, while other conditions remained unchanged.

[0039] Comparative Example 10

[0040] Based on the fire-retardant and pressure-resistant coating of Example 1, the average size of the multilayer graphene oxide was changed to be greater than 2000 nm, while other conditions remained unchanged.

[0041] Example 2

[0042] 10 grams of dispersant and 120 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 100 grams of silica aerogel powder and 200 grams of hollow ceramic microspheres were added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1500 nanometers and a thickness of 5-10 layers; the silica aerogel powder had a size of 300 nanometers; and the nano-hollow ceramic had a size of 100 nanometers.

[0043] 250 g of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B treated above were heated to 70° C. respectively, and components A and B were sprayed onto the surface of the steel plate using a spraying device with a spraying thickness of 1 cm.

[0044] Example 3

[0045] 10 grams of dispersant and 120 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 100 grams of silica aerogel powder and 200 grams of hollow ceramic microspheres were added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1000-1500 nanometers and a thickness of 5-10 layers; the silica aerogel powder had a size of 40 nanometers; and the nano-hollow ceramic had a size of 100 nanometers.

[0046] 250 g of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B treated above were heated to 70° C. respectively, and components A and B were sprayed onto the surface of the steel plate using a spraying device with a spraying thickness of 1 cm.

[0047] Example 4

[0048] 10 grams of dispersant and 120 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 100 grams of silica aerogel powder and 200 grams of hollow ceramic microspheres were added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1000-1500 nanometers and a thickness of >10 layers; the silica aerogel powder had a size of 100 nanometers; and the nano-hollow ceramic had a size of 100 nanometers.

[0049] 250 g of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B treated above were heated to 70° C. respectively, and components A and B were sprayed onto the surface of the steel plate using a spraying device with a spraying thickness of 1 cm.

[0050] Example 5

[0051] 10 grams of dispersant and 120 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 100 grams of silica aerogel powder and 200 grams of hollow ceramic microspheres were added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1000-1500 nanometers and a thickness of ≤3 layers; the silica aerogel powder had a size of 100 nanometers; and the nano-hollow ceramic had a size of 100 nanometers.

[0052] 250 g of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B treated above were heated to 70° C. respectively, and components A and B were sprayed onto the surface of the steel plate using a spraying device with a spraying thickness of 1 cm.

[0053] Example 6

[0054] 10 grams of dispersant and 120 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 100 grams of silica aerogel powder and 200 grams of hollow ceramic microspheres were added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1500 nanometers and a thickness of 5-10 layers; the silica aerogel powder had a size of 100 nanometers; and the nano-hollow ceramic had a size of 300 nanometers.

[0055] 250 g of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B treated above were heated to 70° C. respectively, and components A and B were sprayed onto the surface of the steel plate using a spraying device with a spraying thickness of 1 cm.

[0056] Example 7

[0057] 10 grams of dispersant and 170 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 250 grams of hollow ceramic microspheres were added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1000-1500 nanometers and a thickness of 5-10 layers; the nano hollow ceramic had a size of 100 nanometers.

[0058] 250 g of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B treated above were heated to 70° C. respectively, and components A and B were sprayed onto the surface of the steel plate using a spraying device with a spraying thickness of 1 cm.

[0059] Example 8

[0060] 10 grams of dispersant and 220 grams of multilayer graphene oxide were added to 250 grams of component B (diethyltoluenediamine) and stirred for 10 minutes at 800 rpm. Then, 200 grams of silica aerogel powder was added and stirred for 15 minutes at 800 rpm. Finally, 10 grams of defoamer and 10 grams of leveling agent were added and stirred for 5 minutes at 500 rpm to obtain a component B mixture. The multilayer graphene oxide had a size of 1000-1500 nanometers and 5-10 layers; the silica aerogel powder had a size of 300 nanometers.

[0061] 250 g of component A (2,4'-diphenylmethane diisocyanate) and the mixture of component B treated above were heated to 70° C. respectively, and components A and B were sprayed onto the surface of the steel plate using a spraying device with a spraying thickness of 1 cm.

[0062] Table 1 shows the fire resistance time, heat insulation temperature, smoothness of the paint film after application, and dispersion of various fillers in the fire-retardant and pressure-resistant coating samples prepared in each comparative example. Fire resistance time was tested in accordance with the national standard GB14907-2002 (fire resistance performance). Heat insulation temperature was measured using an infrared thermometer to measure the temperature difference between the front and back surfaces of the fire-retardant coating. Filler dispersion was evaluated in accordance with the national standard GB14907-2002 (in the container).

[0063] Table 1

[0064]

[0065]

[0066] As shown in the table above, the coating of the present invention, prepared according to the formulation of Example 1, exhibits excellent properties and simultaneously addresses the fire protection, heat insulation, and pressure resistance issues of equipment and buildings. Insufficient film-forming material reduces the dispersibility of the filler, resulting in unevenness and a grainy feel after application and curing, and slightly reduced fire protection and heat insulation capabilities. Excessive film-forming material significantly reduces fire protection and heat insulation capabilities. Insufficient silica aerogel powder addition significantly reduces fire protection and heat insulation capabilities. Excessive addition results in poor dispersion and a grainy feel after curing. Insufficient multilayer graphene oxide weakens the dispersion of silica aerogel powder in the film-forming material, resulting in the appearance of numerous particles after application, indicating a synergistic effect between the two in improving coating performance. However, excessive addition of multilayer graphene oxide does not significantly alter the coating's fire protection and heat insulation properties, indicating that the coating's performance has already reached its optimal level and that the addition of graphene oxide reduces its cost-effectiveness. The size of graphene oxide also affects heat resistance. If it's too small, the silica aerogel and nano-hollow ceramics can't fully penetrate the layered structure, reducing the framework's resistance to flames and decreasing the fire resistance time and temperature. While increasing the size of graphene oxide can improve the efficiency with which the two fire-retardant powders can penetrate the layered structure, oversizing it reduces its ability to disperse evenly within the film-forming material, leading to an uneven surface after film formation. The performance changes caused by the addition of nano-hollow ceramics are similar to those of multilayer graphene oxide. Insufficient nano-hollow ceramics can lead to a decrease in thermal insulation performance, while excessive amounts will not significantly improve the coating's performance.

[0067] Table 2 shows the fireproofing time, heat-insulating temperature, smoothness of the paint film after application, and dispersion of various fillers in the fire-retardant and pressure-resistant coating samples prepared in each example. The fireproofing time test was conducted in accordance with the national standard GB14907-2002 (fire resistance performance). The heat-insulating temperature was measured using an infrared thermometer to measure the temperature difference between the front and back surfaces of the fire-retardant coating. The filler dispersion evaluation standard was conducted in accordance with the national standard GB14907-2002 (in the container).

[0068] sample Fire protection time (min) Insulation temperature (°) Flatness Dispersibility of fillers Example 1 120 920 Very flat very good Example 2 100 793 Uneven No, there are particles Example 3 122 924 Very flat very good Example 4 103 805 Uneven No, there are particles Example 5 116 889 smooth very good Example 6 107 825 Very flat very good Example 7 88 664 Very flat very good Example 8 126 932 Very flat very good

[0069] The table above shows that increasing the size of silica aerogel powder leads to decreased solubility, poorer filler dispersion, and uneven cured paint films. While reducing the size of silica aerogel powder improves the coating's fire resistance and thermal insulation, the improvement is not significant and may even reduce the coating's cost-effectiveness. The thickness of multilayer graphene oxide is also closely related to the coating's performance. Increasing the number of layers reduces the total number of graphene oxide sheets, which in turn affects the dispersion of the silica aerogel powder and reduces the coating's fire resistance and thermal insulation properties. Reducing the number of layers results in an insufficient thickness of the carbonized framework upon exposure to open flames, compromising the coating's overall fire resistance and thermal insulation performance. Increasing the size of nano-hollow ceramics increases the collision of air molecules within the hollow core, improving heat transfer and resulting in a decrease in thermal insulation. If silica aerogel powder is not added and multi-layer graphene oxide and nano hollow ceramics are used instead, the fire resistance and thermal insulation capabilities of the coating will be greatly reduced; if silica aerogel powder and multi-layer graphene oxide are used instead of nano hollow ceramics, the fire resistance and thermal insulation properties will be slightly improved, but the material cost will be greatly increased, which is not conducive to product promotion.

[0070] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A fire-retardant and pressure-resistant coating, characterized in that: The fire-retardant and pressure-resistant coating comprises, by weight, 36-66 parts of a film-forming substance, 7-12 parts of a silica aerogel powder, 8-15 parts of multilayer graphene oxide, 15-25 parts of hollow ceramic microspheres, and 2-4 parts of an additive. The film-forming material is a two-component material, wherein component A is 2,4'-diphenylmethane diisocyanate and component B is diethyltoluenediamine, and the mass ratio of components A to B is 1:1; the number of layers of multilayer graphene oxide is 5-10, and the size is 1000-2000 nanometers.

2. The fire-retardant and pressure-resistant coating according to claim 1, characterized in that: The silica aerogel powder size is 50-200 nanometers.

3. The fire-retardant and pressure-resistant coating according to claim 1, characterized in that: Additives include dispersants, defoamers and leveling agents.

4. The fire-retardant and pressure-resistant coating according to claim 1, characterized in that: The size of hollow ceramic microspheres is 50-200 nanometers.

5. The method for preparing the fire-retardant and pressure-resistant coating according to claim 3, characterized in that: Add dispersant and multilayer graphene oxide to component B, stir for 10 minutes at a speed of 800 rpm, then add silica aerogel powder and hollow ceramic microbeads, stir for 15 minutes, maintain the speed at 800 rpm, finally add defoamer and leveling agent, stir for 5 minutes at a speed of 500 rpm to obtain a mixture of component B; spray equipment is used for construction, and the mixture of components A and B is heated to 70°C before construction. When components A and B are sprayed out of the nozzle and come into contact, components A and B react and solidify into a film on the surface of the coating equipment to form a fire-retardant and pressure-resistant coating.

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