Non-expansive refractory coating and preparation method thereof

Abstract

The invention relates to a non-expansive refractory coating and a preparation method thereof, the non-expansive refractory coating comprises a component A and a component B. The component A comprises, by mass, 15-25% of high-alumina cement, 8-12% of refractory soil, 5-10% of glass powder, 5-15% of aluminum hydroxide, 5-10% of hollow glass beads, 2-5% of silica fume, 3-5% of an ethyl cellulose composite system, and the balance modified vitrified microbeads; the component B comprises 10-20% of lithium silicate, 5-10% of an acrylic emulsion, 5-15% of a pure acrylic emulsion, 0.1-0.3% of a water reducing agent, 1-2% of a wetting agent, 1-3% of a coalescing agent and the balance of water; the modified glass beads comprise titanium dioxide composite glass beads, tetrabutyl titanate and silver. The coating has the effect of improving the fire resistance of the coating.

Description

Technical Field

[0001] This application relates to the field of coatings, and in particular to a non-intumescent refractory coating and its preparation method. Background Technology

[0002] Fire-resistant coatings are crucial materials for maintaining the structural integrity of load-bearing components such as building steel structures and industrial equipment during fires. Non-intumescent fire-resistant coatings primarily rely on the high-temperature stability and low thermal conductivity of the coating components themselves to achieve thermal insulation protection. Compared with traditional intumescent coatings, they have advantages such as better durability and higher stability, making them suitable for long-term exposure or harsh environments.

[0003] However, in practical engineering applications, existing non-intumescent refractory coatings still have significant limitations. To achieve a high fire resistance limit, a large coating thickness is usually required, which not only increases material and construction costs but also affects structural load and space utilization. Especially under conventional designs with a coating thickness of approximately 20mm, the fire resistance limit of existing coatings is still insufficient to meet certain high-standard fire resistance time requirements. Their insulation layer is prone to premature instability at high temperatures, accelerating heat transfer and causing a rapid rise in back temperature. Summary of the Invention

[0004] To improve the fire resistance of coatings, this application provides a non-intumescent refractory coating and its preparation method.

[0005] Firstly, this application provides a non-intumescent refractory coating, which adopts the following technical solution: A non-intumescent refractory coating comprises component A and component B. According to the mass percentage, component A comprises: 15-25% high-alumina cement, 8-12% refractory clay, 5-10% glass powder, 5-15% aluminum hydroxide, 5-10% hollow glass microspheres, 2-5% silica fume, 3-5% ethyl cellulose composite system, and the balance being modified vitrified microspheres. Component B comprises: 10-20% lithium silicate, 5-10% acrylic emulsion, 5-15% pure acrylic emulsion, 0.1-0.3% water-reducing agent, 1-2% wetting agent, 1-3% film-forming aid, and the balance being water; The modified vitrified microspheres include titanium dioxide composite glass microspheres, tetrabutyl titanate, and silver.

[0006] By adopting the above technical solution, the high-alumina cement, refractory clay, and silica fume in component A constitute a high-temperature stable inorganic skeleton. The melting of aluminum hydroxide and glass powder at high temperature promotes the formation of ceramic phase and improves density. Modified vitrified microspheres are used as the core heat-insulating filler, and the silver and titanium dioxide they contain enhance heat reflectivity. The composite of lithium silicate, acrylic emulsion, and pure acrylic emulsion in component B provides bonding strength and film-forming properties at room temperature, and forms a silicate network structure at high temperature. The addition of the ethyl cellulose composite system improves the flexibility of the coating. The synergistic effect between the various components improves the fire resistance and crack resistance of the coating.

[0007] Preferably, the titanium dioxide composite glass microspheres are prepared by the following method: Titanium dioxide was mixed with ethanol to obtain a titanium dioxide dispersion. Hollow glass microspheres were added to the titanium dioxide dispersion, heated and stirred, then filtered, washed, dried and calcined, and cooled to obtain titanium dioxide composite glass microspheres.

[0008] By adopting the above technical solution, through liquid phase dispersion and stirring, nano-titanium dioxide particles are adsorbed onto the surface of hollow glass microspheres. After calcination, the titanium dioxide and the surface of hollow glass microspheres are more firmly bonded, forming a stable titanium dioxide layer, which effectively improves the reflectivity of hollow glass microspheres to thermal radiation.

[0009] Preferably, the mass ratio of the hollow glass microspheres to titanium dioxide is 1:(1.1-1.3).

[0010] By adopting the above technical solution, the mass ratio between hollow glass microspheres and titanium dioxide is preferably within the above range, so that titanium dioxide forms a complete, uniform and moderately thick coating layer on the surface of hollow glass microspheres, and the microspheres maintain good dispersion performance in the system.

[0011] Preferably, the modified vitrified microspheres are prepared by the following method: Tetrabutyl titanate, water, and hydrogen chloride were mixed to obtain a tetrabutyl titanate solution. Titanium dioxide composite glass microspheres were added to the tetrabutyl titanate solution and subjected to a hydrothermal reaction. After the reaction, the mixture was filtered and washed alternately with deionized water and ethanol to remove impurities. Then, it was dried to obtain a preform. Silver nitrate was mixed with water to obtain a silver nitrate solution. The preform was added to a glucose solution, followed by the addition of sodium hydroxide solution to obtain a mixture. The mixture was added to the silver nitrate solution, followed by the addition of sodium hydroxide solution. The mixture was reacted under water bath conditions. After the reaction, the mixture was filtered, washed, and dried to obtain modified vitrified microspheres.

[0012] By adopting the above technical solution, firstly, the existing titanium dioxide coating is further grown and modified by the condensation of tetrabutyl titanate and water to form a more stable titanium oxide, which enhances the high temperature resistance and corrosion resistance of the hollow glass microspheres. Then, a high reflectivity nanolayer is uniformly deposited on the surface of the hollow glass microspheres through the silver mirror reaction. The modified vitrified microspheres prepared have good thermal reflection efficiency and high temperature stability.

[0013] Preferably, the mass ratio of the tetrabutyl titanate, titanium dioxide composite glass microspheres to hydrogen chloride is 1:(2.2-2.6):3.

[0014] By adopting the above technical solution, the mass ratio between tetrabutyl titanate, titanium dioxide composite glass microspheres and hydrogen chloride is preferably within the above range, the hydrolysis rate of tetrabutyl titanate is moderate, and the obtained modified vitrified microspheres have good stability.

[0015] Preferably, the mass ratio of the preform to silver nitrate is 1:(2.4-2.8).

[0016] By adopting the above technical solution, and preferably within the above range the mass ratio between the preform and silver nitrate, a continuous, dense, and highly reflective nano-silver film is formed, and the phenomenon of excessive silver and excessive thickness is reduced.

[0017] Preferably, the ethyl cellulose composite system includes amino cellulose, pimelic acid, and epoxidized soybean oil.

[0018] By adopting the above technical solution, a network structure with toughness and reactivity is obtained through the reaction between aminocellulose, pimelic acid and epoxidized soybean oil. This network structure enhances the toughness and adhesion of the coating and promotes char formation at high temperatures, thereby improving the stability of the char layer and effectively improving the problem of coating cracking.

[0019] Preferably, the ethyl cellulose composite system is prepared by the following method: Ethyl cellulose was amination to obtain amino cellulose. Amino cellulose, cysteine ​​hydrochloride, azobisisobutyronitrile and ethanol were mixed and reacted to obtain an amino cellulose solution. Epoxidized soybean oil and pimelic acid were mixed and reacted at high temperature. The reaction product was diluted with ethyl acetate, then extracted, and the ethyl acetate was removed by rotary evaporation. The product was then added to the amino cellulose solution, stirred and dried to obtain an ethyl cellulose composite system.

[0020] By adopting the above technical solution, reactive amino groups are introduced into ethyl cellulose through amination treatment. Then, cysteine ​​hydrochloride and azobisisobutyronitrile are added to the reaction to introduce more active groups into the amino cellulose molecular chain, which enhances its compatibility in the system. At the same time, pimelic acid and epoxidized soybean oil undergo ring-opening esterification reaction. Finally, the two are combined to form a chemically cross-linked ethyl cellulose composite system, which further improves the overall stability of the system.

[0021] Preferably, the mass ratio of aminocellulose, pimelic acid and epoxidized soybean oil is (1.1-1.3):1:0.49.

[0022] By adopting the above technical solution, the mass ratio of aminocellulose, pimelic acid and epoxidized soybean oil is preferably within the above range, which balances the reaction stability among the components. The prepared ethylcellulose has good flexibility and reactivity, and also has good stability in the system.

[0023] Secondly, this application provides a method for preparing a non-intumescent refractory coating, employing the following technical solution: A method for preparing a non-intumescent refractory coating includes the following steps: Mix the raw materials in formulation A evenly to obtain component A; mix the raw materials in formulation B evenly to obtain component B; while maintaining the stirring condition for component B, add component A to component B and continue stirring to finally obtain a non-intumescent refractory coating.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. By designing a two-component system comprising a high-alumina cement-refractory clay inorganic skeleton, modified vitrified microsphere thermal insulation filler, and ethyl cellulose composite reinforcing agent, the components produce a synergistic effect at both room temperature and high temperature, significantly improving the coating's fire resistance, ablation resistance, and crack resistance. 2. By constructing modified vitrified microspheres with a titanium dioxide intermediate layer and a nano-silver outer layer structure, the coating's ability to reflect and block heat radiation is enhanced, thereby improving the coating's heat insulation effect and fire resistance durability. 3. An organic composite reinforcing network formed by the reaction of aminocellulose, pimelic acid and epoxidized soybean oil is introduced, which effectively improves the flexibility, adhesion and high-temperature char stability of the coating, and improves the cracking and peeling of the coating caused by thermal stress. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments: Raw material description: All raw materials in the examples are commercially available; the high-alumina cement is aluminate cement, and in this application it is Litte brand CA50 refractory cement; the refractory clay is soft refractory clay; the glass powder was purchased from Tuoyi New Materials (Guangzhou) Co., Ltd., TY-906, 1500 mesh, with an initial melting-to-complete melting temperature of 420-480℃; the hollow glass microspheres and hollow glass microspheres are 50-70 mesh vitrified microspheres purchased from Xinyu New Materials; the acrylic emulsion is Dow TX-100; the pure acrylic emulsion is Badifu RS-2608; the water-reducing agent is polycarboxylate water-reducing agent; the film-forming aid is 12-carbon alcohol ester; and the wetting agent is Klein LCN407.

[0026] Example 1 Preparation of titanium dioxide composite glass microspheres: 400 mL of saturated calcium hydroxide solution was heated to 90 °C under magnetic stirring. Untreated hollow glass microspheres were then added and heated for 6 h. After treatment, the microspheres were filtered and washed with deionized water and dried at 60 °C for 8 h to obtain hollow glass microspheres. 20.95 g of titanium dioxide was mixed with deionized water to obtain a 5% titanium dioxide dispersion. The titanium dioxide dispersion was heated to 80 °C and maintained at 800 rpm. 19.05 g of hollow glass microspheres were then added to the stirred titanium dioxide dispersion and stirred for 6 h. After filtration, the microspheres were washed with deionized water and dried at 60 °C for 8 h. Finally, the microspheres were calcined in a muffle furnace at 450 °C for 1.5 h and then naturally cooled to 25 °C to obtain titanium dioxide composite glass microspheres.

[0027] Preparation of modified vitrified microspheres: 48.39 g of hydrogen chloride was mixed with 50 g of water and stirred to obtain a hydrogen chloride solution. 16.13 g of tetrabutyl titanate (CAS No.: 5593-70-4) and 35.48 g of titanium dioxide composite glass microspheres were added to the hydrogen chloride solution, transferred to a reaction vessel, heated to 160℃ and reacted for 8 h. The mixture was then naturally cooled to 25℃, washed three times alternately with deionized water and anhydrous ethanol, and dried in an oven at 50℃ for 10 h to obtain the preform. 70.59 g of... 29.41 g of the preform was mixed with deionized water to obtain a 0.6 mol / L silver nitrate solution. 29.41 g of the preform was added to a 15% glucose solution (CAS No.: 58367-01-4), stirred, and then added to the silver nitrate solution. 5 g of a 10% sodium hydroxide solution was then added, and the mixture was reacted in a water bath at 40 °C for 2 h. After the reaction, the mixture was filtered, washed alternately with deionized water and ethanol, and dried in an oven at 60 °C for 10 h to obtain modified vitrified microspheres.

[0028] Preparation of ethyl cellulose composite system: 50g of ethyl cellulose (CAS No.: 9004-57-3) was added to 300g of N,N-dimethylformamide (CAS No.: 68-12-2), followed by the addition of 65.4g of triethylamine (CAS No.: 121-44-8) and 23.2g of 2-chloroethylamine hydrochloride (CAS No.: 870-24-6). The mixture was heated to 80℃ under nitrogen protection and reacted for 18h. After the reaction, the precipitate was poured into ice water, filtered, and washed with dilute hydrochloric acid, deionized water, and ethanol. The precipitate was then dried under vacuum at 60℃ for 8h to obtain aminoated ethyl cellulose. 21.24g of aminoated cellulose, 10g of cysteine ​​hydrochloride (CAS No.: 156-57-0), 0.1g of azobisisobutyronitrile (CAS No.: 78-67-1), and 300g of ethanol were mixed and reacted at 75℃ for 8h to obtain an aminoated ethyl cellulose solution.

[0029] 9.45 g of epoxidized soybean oil (CAS No.: 8013-07-8) and 19.31 g of pimelic acid (CAS No.: 111-16-0) were mixed and reacted at 116 °C for 5 h. After the reaction, the reactants were diluted with excess ethyl acetate (CAS No.: 141-78-6), and then extracted with 10% sodium chloride solution and collected the organic phase. The ethyl acetate was removed by rotary evaporation, and the mixture was dried at 45 °C. The mixture was added to an aminoated ethyl cellulose solution, mixed evenly, dried at 60 °C for 8 h, and pulverized to obtain an ethyl cellulose composite system.

[0030] Preparation of non-intumescent refractory coatings: Prepare the following components according to the mass percentage: Component A: 15% high-alumina cement, 8% refractory clay, 5% glass powder, 2% aluminum hydroxide, 2% silica fume, 5% hollow glass microspheres, 3% ethyl cellulose composite system, with the remainder being modified vitrified microspheres; Component B: 10% lithium silicate, 5% acrylic emulsion, 5% pure acrylic emulsion, 0.1% water-reducing agent, 1% wetting agent, 1% film-forming aid, and the balance is water; The raw materials in component A are dry-mixed and stirred evenly to obtain component A. The water, lithium silicate solution, acrylic solution, and pure acrylic emulsion in component B are mixed and stirred at 300 rpm for 10 min. Then, film-forming aid, water-reducing agent, and wetting agent are added and stirred at 150 rpm for 20 min to obtain component B. Component B is stirred at 60 rpm, and component A is added to the stirred component B. Stirring is continued for 2 min to obtain a non-intumescent refractory coating, wherein the mass ratio between component A and component B is 2:1.

[0031] Example 2 Preparation of titanium dioxide composite glass microspheres: 400 mL of saturated calcium hydroxide solution was heated to 90 °C under magnetic stirring. Untreated hollow glass microspheres were then added and heated for 6 h. After treatment, the microspheres were filtered and washed with deionized water and dried at 60 °C for 8 h to obtain hollow glass microspheres. 22.61 g of titanium dioxide was mixed with deionized water to obtain a 5% titanium dioxide dispersion. The titanium dioxide dispersion was heated to 80 °C and maintained at 800 rpm. Then, 17.39 g of hollow glass microspheres were added to the stirred titanium dioxide dispersion and stirred for 6 h. After filtration, the microspheres were washed with deionized water and dried at 60 °C for 8 h. Finally, the microspheres were calcined in a muffle furnace at 450 °C for 1.5 h and then naturally cooled to 25 °C to obtain titanium dioxide composite glass microspheres.

[0032] Preparation of modified vitrified microspheres: 45.46 g of hydrogen chloride was mixed with 50 g of water and stirred to obtain a hydrogen chloride solution. 15.15 g of tetrabutyl titanate and 39.39 g of titanium dioxide composite glass microspheres were added to the hydrogen chloride solution and transferred to a reaction vessel. The mixture was heated to 160 °C and reacted for 8 h. After naturally cooling to 25 °C, the mixture was washed three times alternately with deionized water and anhydrous ethanol and dried in an oven at 50 °C for 10 h to obtain the preform. 73.68 g of silver nitrate was mixed with deionized water to obtain a 0.6 mol / L silver nitrate solution. 26.32 g of the preform was added to a 15% glucose solution and stirred. Then, the mixture was added to the silver nitrate solution, followed by 5 g of 10% sodium hydroxide solution. The mixture was reacted in a water bath at 40 °C for 2 h. After the reaction, the mixture was filtered, washed alternately with deionized water and ethanol, and dried in an oven at 60 °C for 10 h to obtain modified vitrified microspheres.

[0033] Preparation of ethyl cellulose composite system: 50g of ethyl cellulose was added to 300g of N,N-dimethylformamide, followed by 65.4g of triethylamine and 23.2g of 2-chloroethylamine hydrochloride. The mixture was heated to 80℃ for 18h under nitrogen protection. After the reaction, the precipitate was poured into ice water and filtered. The precipitate was washed with dilute hydrochloric acid, deionized water, and ethanol, and then dried under vacuum at 60℃ for 8h to obtain aminoated ethyl cellulose. 23.3g of aminoated cellulose, 10g of cysteine ​​hydrochloride, 0.1g of azobisisobutyronitrile, and 300g of ethanol were mixed and reacted at 75℃ for 8h to obtain an aminoated ethyl cellulose solution.

[0034] 8.78 g of epoxidized soybean oil and 17.92 g of pimelic acid were mixed and reacted at 116 °C for 5 h. After the reaction, the reactants were diluted with excess ethyl acetate, then extracted with 10% sodium chloride solution and the organic phase was collected. Ethyl acetate was removed by rotary evaporation and dried at 45 °C. The mixture was added to an aminoated ethyl cellulose solution, mixed evenly, and dried at 60 °C for 8 h. After pulverization, the ethyl cellulose composite system was obtained.

[0035] Preparation of non-intumescent refractory coatings: Prepare the following components according to the mass percentage: Component A: 25% high-alumina cement, 12% refractory clay, 15% glass powder, 5% aluminum hydroxide, 5% silica fume, 10% hollow glass microspheres, 5% ethyl cellulose composite system, with the balance being modified vitrified microspheres; Component B: 20% lithium silicate, 10% acrylic emulsion, 15% pure acrylic emulsion, 0.3% water-reducing agent, 2% wetting agent, 3% film-forming aid, and the balance is water; The raw materials in component A are dry-mixed and stirred evenly to obtain component A. The water, lithium silicate solution, acrylic solution, and pure acrylic emulsion in component B are mixed and stirred at 300 rpm for 10 min. Then, film-forming aid, water-reducing agent, and wetting agent are added and stirred at 150 rpm for 20 min to obtain component B. Component B is stirred at 60 rpm, and component A is added to the stirred component B. Stirring is continued for 2 min to obtain a non-intumescent refractory coating, wherein the mass ratio between component A and component B is 2:1.

[0036] Example 3 Preparation of titanium dioxide composite glass microspheres: 400 mL of saturated calcium hydroxide solution was heated to 90 °C under magnetic stirring. Untreated hollow glass microspheres were then added and heated for 6 h. After treatment, the microspheres were filtered and washed with deionized water and dried at 60 °C for 8 h to obtain hollow glass microspheres. 21.82 g of titanium dioxide was mixed with deionized water to obtain a 5% titanium dioxide dispersion. The titanium dioxide dispersion was heated to 80 °C and maintained at 800 rpm. Then, 18.18 g of hollow glass microspheres were added to the stirred titanium dioxide dispersion and stirred for 6 h. After filtration, the microspheres were washed with deionized water and dried at 60 °C for 8 h. Finally, the microspheres were calcined in a muffle furnace at 450 °C for 1.5 h and then naturally cooled to 25 °C to obtain titanium dioxide composite glass microspheres.

[0037] Preparation of modified vitrified microspheres: 46.87 g of hydrogen chloride was mixed with 50 g of water and stirred to obtain a hydrogen chloride solution. 15.63 g of tetrabutyl titanate and 37.5 g of titanium dioxide composite glass microspheres were added to the hydrogen chloride solution and transferred to a reaction vessel. The mixture was heated to 160 °C and reacted for 8 h. After naturally cooling to 25 °C, the mixture was washed three times alternately with deionized water and anhydrous ethanol and dried in an oven at 50 °C for 10 h to obtain the preform. 72.22 g of silver nitrate was mixed with deionized water to obtain a 0.6 mol / L silver nitrate solution. 27.78 g of the preform was added to a 15% glucose solution and stirred. Then, the mixture was added to the silver nitrate solution, followed by 5 g of 10% sodium hydroxide solution. The mixture was reacted in a water bath at 40 °C for 2 h. After the reaction, the mixture was filtered, washed alternately with deionized water and ethanol, and dried in an oven at 60 °C for 10 h to obtain modified vitrified microspheres.

[0038] Preparation of ethyl cellulose composite system: 50g of ethyl cellulose was added to 300g of N,N-dimethylformamide, followed by 65.4g of triethylamine and 23.2g of 2-chloroethylamine hydrochloride. The mixture was heated to 80℃ for 18h under nitrogen protection. After the reaction, the precipitate was poured into ice water, filtered, and washed with dilute hydrochloric acid, deionized water, and ethanol. The precipitate was then vacuum dried at 60℃ for 8h to obtain aminoated ethyl cellulose. 22.3g of aminoated cellulose, 10g of cysteine ​​hydrochloride, 0.1g of azobisisobutyronitrile, and 300g of ethanol were mixed and reacted at 75℃ for 8h to obtain an aminoated ethyl cellulose solution.

[0039] 9.11 g of epoxidized soybean oil and 18.59 g of pimelic acid were mixed and reacted at 116 °C for 5 h. After the reaction, the reactants were diluted with excess ethyl acetate, then extracted with 10% sodium chloride solution and the organic phase was collected. Ethyl acetate was removed by rotary evaporation and dried at 45 °C. The mixture was added to an aminoated ethyl cellulose solution, mixed evenly, and dried at 60 °C for 8 h. After pulverization, the ethyl cellulose composite system was obtained.

[0040] Preparation of non-intumescent refractory coatings: Prepare the following components according to the mass percentage: Component A: 20% high-alumina cement, 10% refractory clay, 10% glass powder, 3.5% aluminum hydroxide, 7.5% silica fume, 7.5% hollow glass microspheres, 3.5% ethyl cellulose composite system, with the balance being modified vitrified microspheres; Component B: 15% lithium silicate, 7.5% acrylic emulsion, 10% pure acrylic emulsion, 0.2% water-reducing agent, 1.5% wetting agent, 2% film-forming aid, and the balance is water; The raw materials in component A are dry-mixed and stirred evenly to obtain component A. The water, lithium silicate solution, acrylic solution, and pure acrylic emulsion in component B are mixed and stirred at 300 rpm for 10 min. Then, film-forming aid, water-reducing agent, and wetting agent are added and stirred at 150 rpm for 20 min to obtain component B. Component B is stirred at 60 rpm, and component A is added to the stirred component B. Stirring is continued for 2 min to obtain a non-intumescent refractory coating, wherein the mass ratio between component A and component B is 2:1.

[0041] Example 4 Example 4 is based on Example 3. In Example 4, when preparing titanium dioxide composite glass microspheres, 22.22g of hollow glass microspheres and 17.78g of titanium dioxide were used.

[0042] Example 5 Example 5 is based on Example 3. In Example 5, when preparing titanium dioxide composite glass microspheres, 15.38g of hollow glass microspheres and 24.62g of titanium dioxide were used.

[0043] Example 6 Example 6 is based on Example 3. In Example 6, when preparing modified vitrified microspheres, 18.18 g of tetrabutyl titanate, 27.27 g of titanium dioxide composite glass microspheres, and 54.55 g of hydrogen chloride were used.

[0044] Example 7 Example 7 is based on Example 3. In Example 7, when preparing modified vitrified microspheres, 13.89g of tetrabutyl titanate, 44.44g of titanium dioxide composite glass microspheres, and 41.67g of hydrogen chloride were used.

[0045] Example 8 Example 8 is based on Example 3. In Example 8, when preparing modified vitrified microspheres, the preform used was 33.33g and the silver nitrate was 66.67g.

[0046] Example 9 Example 9 is based on Example 3. In Example 9, when preparing modified vitrified microspheres, the preform used was 23.81g and the silver nitrate was 76.19g.

[0047] Example 10 Example 10 is based on Example 3. In Example 10, when preparing the ethyl cellulose composite system, the amount of amino cellulose used was 17.47 g, the amount of pimelic acid was 21.83 g, and the amount of epoxidized soybean oil was 10.7 g.

[0048] Example 11 Example 11 is based on Example 3. In Example 11, when preparing the ethyl cellulose composite system, the amount of amino cellulose used was 25.89g, the amount of pimelic acid was 16.18g, and the amount of epoxidized soybean oil was 7.93g.

[0049] Example 12 Example 12 is based on Example 3. In Example 12, when preparing the ethyl cellulose composite system, amino cellulose was replaced with unmodified ethyl cellulose.

[0050] Example 13 Example 13 is based on Example 3, except that the modified vitrified microspheres are replaced with an equal amount of titanium dioxide composite glass microspheres.

[0051] Example 14 Example 14 is based on Example 3, except that the preform is replaced with an equal amount of titanium dioxide composite glass microspheres and the preform is not subjected to a silver mirror reaction.

[0052] Comparative Example 1 Comparative Example 1 is based on Example 3, except that the modified vitrified microspheres are replaced with an equal amount of ordinary hollow glass microspheres.

[0053] Comparative Example 2 Comparative Example 2 is based on Example 3, except that the ethyl cellulose composite system is replaced with an equal amount of amino cellulose.

[0054] Comparative Example 3 Comparative Example 3 is based on Example 3, except that aminocellulose is replaced with an equal amount of hydroxypropyl methylcellulose (CAS No.: 9004-65-3).

[0055] Performance testing Samples from Examples 1-14 and Comparative Examples 1-3 were taken and subjected to the following performance tests: (1) Bond strength Using GB 14907—2018 as the testing reference, the bonding strength of the samples was tested. Each sample was tested 3 times, and the average value was taken. The test results were recorded in Table 1.

[0056] (2) Compressive strength Using GB 14907—2018 and GB / T 5486—2008 as testing references, the compressive strength of the samples was tested. Each sample was tested three times, and the average value was taken. The test results were recorded in Table 1.

[0057] (3) Dry density Prepare a 100mm×100mm×20mm test block, cure it for 28 days, dry it to constant weight, weigh it and measure its volume, and calculate the dry density per unit volume.

[0058] (4) Fire resistance Using GB / T 9978.1—2008 as the testing reference, the fire resistance performance of the samples was tested. Each sample was tested 3 times, and the average value was taken. The test results were recorded in Table 1.

[0059] (5) Water absorption Prepare cement mortar blocks measuring 70mm × 70mm × 20mm, uniformly coat them with a 5mm thick coating, and cure them for 28 days at a temperature of (23±2)℃ and a relative humidity of (50±5)%. Seal all surfaces except the test surface with a molten rosin-paraffin mixture, weigh (M1), and then invert them into a water tank, maintaining the water level at half the height of the block. After soaking for (120±0.5) min, remove the block, wipe off the surface water with a damp towel, and weigh it immediately (M2). The water absorption is calculated using the formula W=(M2-M1) / A, where A is the area of ​​the test surface (0.0049m²). Each sample is tested three times, and the average value is taken. The test results are recorded in Table 1.

[0060] Performance test results of Examples 1-14 and Comparative Examples 1-3

[0061] As shown in Table 1, the bonding strength of Examples 1-3 is all 0.48 MPa or above, the compressive strength is all 1.00 MPa or above, and the dry density is all 515 kg / m³. 3 The fire resistance time is 185 min or more and the water absorption is less than 9 g, indicating that the non-intumescent refractory coating prepared in this application has good mechanical strength, fire resistance and good water absorption resistance.

[0062] In Examples 4 and 5, the mass ratio between hollow glass microspheres and titanium dioxide was not within the range specified in this application. When the amount of titanium dioxide was insufficient, it was difficult to form a complete and uniform coating layer on the surface of the hollow glass microspheres, and it could only be locally adsorbed. This made it difficult for the subsequent silver layer to form a continuous reflective film, reducing the bonding points between the hollow glass microspheres and the coating substrate and resulting in excessive internal pores. When the amount of titanium dioxide was excessive, agglomeration occurred, making it difficult to be uniformly adsorbed on the surface of the hollow glass microspheres, and reducing the internal stability of the coating.

[0063] In Examples 6 and 7, the mass ratios of tetrabutyl titanate, titanium dioxide composite glass microspheres, and hydrogen chloride were not within the range specified in this application. When there were insufficient titanium dioxide composite glass microspheres, excessive tetrabutyl titanate would generate an excessively thick Ti-O network, resulting in an overly thick coating layer and decreased stability. When there were excessive titanium dioxide composite glass microspheres, tetrabutyl titanate could not completely coat the surface of the titanium dioxide composite glass microspheres, resulting in an incomplete Ti-O network. Consequently, the bonding sites between the prepared modified vitrified microspheres and the coating matrix decreased, leading to decreased stability.

[0064] In Examples 8 and 9, the mass ratio between the preform and silver nitrate is not within the range specified in this application. When silver nitrate is insufficient, it is difficult to form a continuous nano-silver film on the surface of the preform, resulting in decreased fire resistance and interface stability, and also increased hydrophilicity of the modified vitrified microspheres. When silver nitrate is excessive, the silver layer is too thick, causing the glass microspheres to become less tough and crack, thus forming interconnected voids, increasing the heat conduction path, and reducing fire resistance and stability.

[0065] In Examples 10 and 11, the mass ratios of aminocellulose, pimelic acid, and epoxidized soybean oil were not within the range specified in this application. When aminocellulose was insufficient, there were not enough cross-linking sites, making it difficult to form a stable network with pimelic acid and epoxidized soybean oil, resulting in decreased coating stability, insufficient high-temperature char formation synergy, and decreased refractory performance. When aminocellulose was excessive, the cross-linking density was too high, resulting in excessive brittleness, decreased crack resistance, and easy breakage at high temperatures, which damaged the integrity of the char layer and reduced the interfacial compatibility of the modified vitrified microspheres.

[0066] Example 12 did not involve amination of ethyl cellulose, resulting in the absence of active sites and difficulty in crosslinking with pimelic acid and epoxidized soybean oil. Consequently, it could not form a tough, supportive network structure, exhibited poor interfacial bonding, and decreased stability.

[0067] Example 13 only attaches titanium dioxide to the surface of hollow glass microspheres, lacking the Ti-O network of tetrabutyl titanate, resulting in decreased corrosion resistance, decreased thermal insulation performance, and a significant decrease in the adhesion between the hollow glass microspheres and the substrate.

[0068] Example 14 did not involve a silver mirror reaction on the preform, lacking the high reflectivity of the nano-silver film. This resulted in the inability to effectively block heat radiation, reduced fire resistance, and increased hydrophilicity.

[0069] Comparative Example 1 replaced the modified vitrified microspheres with ordinary hollow glass microspheres. Without TiO2 loading and Ti-O network coating, the high temperature resistance and corrosion resistance were reduced, and the thermal insulation efficiency was difficult to improve further. The surface of ordinary hollow glass microspheres is inert, making it difficult to form a good interface bond with the coating matrix, resulting in decreased stability.

[0070] Comparative Example 2 replaced the ethyl cellulose composite system with an equal amount of amino cellulose. Lacking the flexible chains of pimelic acid and modified epoxidized soybean oil, it was difficult to form a rigid cross-linked and flexible toughened network structure. The coating became more brittle, the mechanical strength decreased, and the interfacial compatibility also decreased.

[0071] In Comparative Example 3, the ethyl cellulose composite system was replaced with an equal amount of hydroxypropyl methyl cellulose. Ordinary hydroxypropyl methyl cellulose does not have amino active sites and cannot form chemical bonds with Ti-O on the surface of the modified vitrified microspheres. As a result, the interfacial compatibility is difficult to improve further, and the overall stability of the coating system decreases.

[0072] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. A non-intumescent refractory coating, characterized in that: The product comprises component A and component B. By mass percentage, component A comprises: 15-25% high-alumina cement, 8-12% refractory clay, 5-10% glass powder, 5-15% aluminum hydroxide, 5-10% hollow glass microspheres, 2-5% silica fume, 3-5% ethyl cellulose composite system, and the balance being modified vitrified microspheres. Component B comprises: 10-20% lithium silicate, 5-10% acrylic emulsion, 5-15% pure acrylic emulsion, 0.1-0.3% water-reducing agent, 1-2% wetting agent, 1-3% film-forming aid, and the balance being water; The modified vitrified microspheres include titanium dioxide composite glass microspheres, tetrabutyl titanate, and silver.

2. The non-intumescent refractory coating according to claim 1, characterized in that: The titanium dioxide composite glass microspheres were prepared by the following method: Titanium dioxide was mixed with ethanol to obtain a titanium dioxide dispersion. Hollow glass microspheres were added to the titanium dioxide dispersion, heated and stirred, then filtered, washed, dried and calcined, and cooled to obtain titanium dioxide composite glass microspheres.

3. The non-intumescent refractory coating according to claim 2, characterized in that: The mass ratio of the hollow glass microspheres to titanium dioxide is 1:(1.1-1.3).

4. The non-intumescent refractory coating according to claim 1, characterized in that: The modified vitrified microspheres were prepared using the following method: Tetrabutyl titanate, water, and hydrogen chloride were mixed to obtain a tetrabutyl titanate solution. Titanium dioxide composite glass microspheres were added to the tetrabutyl titanate solution and subjected to a hydrothermal reaction. After the reaction, the mixture was filtered and washed alternately with deionized water and ethanol to remove impurities. Then, it was dried to obtain a preform. Silver nitrate was mixed with water to obtain a silver nitrate solution. The preform was added to a glucose solution, followed by the addition of sodium hydroxide solution to obtain a mixture. The mixture was added to the silver nitrate solution, followed by the addition of sodium hydroxide solution. The mixture was reacted under water bath conditions. After the reaction, the mixture was filtered, washed, and dried to obtain modified vitrified microspheres.

5. The non-intumescent refractory coating according to claim 4, characterized in that: The mass ratio of the tetrabutyl titanate, titanium dioxide composite glass microspheres to hydrogen chloride is 1:(2.2-2.6):

3.

6. The non-intumescent refractory coating according to claim 4, characterized in that: The mass ratio of the preform to silver nitrate is 1:(2.4-2.8).

7. The non-intumescent refractory coating according to claim 1, characterized in that: The ethyl cellulose composite system includes amino cellulose, pimelic acid, and epoxidized soybean oil.

8. The non-intumescent refractory coating according to claim 7, characterized in that: The ethyl cellulose composite system was prepared by the following method: Ethyl cellulose was amination to obtain amino cellulose. Amino cellulose, cysteine ​​hydrochloride, azobisisobutyronitrile and ethanol were mixed and reacted to obtain an amino cellulose solution. Epoxidized soybean oil and pimelic acid were mixed and reacted at high temperature. The reaction product was diluted with ethyl acetate, then extracted, and the ethyl acetate was removed by rotary evaporation. The product was then added to the amino cellulose solution, stirred and dried to obtain an ethyl cellulose composite system.

9. A non-intumescent refractory coating according to claim 8, characterized in that: The mass ratio of aminocellulose, pimelic acid and epoxidized soybean oil is (1.1-1.3):1:0.

49.

10. A non-intumescent refractory coating applied to any one of claims 1-9, characterized in that: Includes the following steps: Mix the raw materials in formulation A evenly to obtain component A; mix the raw materials in formulation B evenly to obtain component B; while maintaining the stirring condition for component B, add component A to component B and continue stirring to finally obtain a non-intumescent refractory coating.

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