Multifunctional intumescent tunnel fireproof coating and preparation method thereof

Abstract

The invention provides a multifunctional intumescent tunnel fireproof coating, which is prepared from the following ingredients in percentage by mass: 10 to 50 percent of polymer emulsion, 10 to 25 percent of water, 10 to 35 percent of dehydrating agents, 5 to 15 percent of charring agents, 8 to 18 percent of foaming agents, 1 to 20 percent of brightening fillers, 1 to 20 percent of water repellents, 0 to 10 percent of inorganic intumescent materials, 0 to 10 percent of inorganic flame retardants, 0 to 5 percent of pigments, 0.1 to 0.5 percent of thickening agents and 0.2 to 1 percent of dispersing agents. And 0.2%-1% of a defoaming agent. According to the coating, a water-based emulsion is used as a film forming substance, an intumescent fireproof flame retardant, a diffuse reflection material, a water repellent and an auxiliary agent are added, and the water-based intumescent tunnel fireproof coating with the functions of fire prevention, flame retardance, brightening, energy conservation, self-cleaning and the like is prepared. The low-VOC foamed carbon tunnel has the advantages of being low in VOC, safe and environmentally friendly, has the characteristics of being high in foamed carbon layer strength and good in heat insulation and fireproof performance, and can meet the fireproof safety requirements of various tunnels such as highway tunnels, railway tunnels and subway tunnels.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to a multifunctional intumescent tunnel fire retardant coating and a preparation method thereof. Background Art

[0002] Once a fire occurs in a tunnel, the fierce fire and prolonged high temperature will cause serious damage to the facilities and equipment inside the tunnel, resulting in serious safety accidents. Although the reinforced concrete structure in the tunnel is non-combustible, its fire resistance is limited, and fire prevention has become an important issue in tunnel engineering. At present, tunnel fire retardant coatings are mainly non-expanding thick fire retardant coatings, with cement as the main binder. During construction, more than 3 coats are required, with low construction efficiency, long maintenance cycle, and coating thickness of up to 15-20mm. The wind speed and vibration generated by driving in the tunnel can easily cause the fire retardant coating to fall off, posing a threat to the safety of vehicles and personnel.

[0003] On the other hand, tunnel lighting consumes a lot of electric energy and has become a heavy burden on tunnel operations; and the accumulation of dust on the inner wall of the tunnel not only affects health and hygiene, but also reduces the lighting effect. In recent years, it is no longer limited to the improvement of the lighting system. The auxiliary lighting of the tunnel wall decoration materials has also become a focus of attention. In the prior art, the inner wall of the tunnel is decorated with diffuse reflection, reflective or luminous materials to improve the lighting conditions of the tunnel road. The mixture of carbon black and solid particles formed by dust, muddy water, and automobile exhaust in the tunnel is eventually deposited on the inner wall of the tunnel, causing serious pollution, making the traffic lights and lighting systems of the tunnel dim, and the air quality of the tunnel deteriorating. Therefore, the traditional solution cannot meet the above-mentioned tunnel construction needs, and the existing tunnel fire retardant coating preparation efficiency is low, and transportation and transfer are required between different processes, and the equipment cost is high. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a multifunctional intumescent tunnel fire retardant coating and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology. The fire retardant coating provided by the present invention has excellent fire retardant performance, light weight, good safety performance, and has the advantages of being green and environmentally friendly, small dosage, and convenient construction. It also has high preparation efficiency, reduces equipment costs, and can be mass-produced.

[0005] In order to achieve the above-mentioned purpose, the present invention is realized through the following technical scheme: a multifunctional intumescent tunnel fire retardant coating, which is composed of the following components by mass percentage: 10% to 50% of polymer emulsion, 10% to 25% of water, 10% to 35% of dehydrating agent, 5% to 15% of carbonizing agent, 8% to 18% of foaming agent, 1% to 20% of brightening filler, 1% to 20% of hydrophobic agent, 0% to 10% of inorganic expanding material, 0% to 10% of inorganic flame retardant, 0% to 5% of pigment, 0.1% to 0.5% of thickener, 0.2% to 1% of dispersant and 0.2% to 1% of defoaming agent.

[0006] Furthermore, the polymer emulsion is pure acrylic emulsion, vinyl acetate emulsion, vinyl acetate acrylic emulsion, styrene acrylic emulsion, vinyl acetate-ethylene copolymer emulsion, and its solid content is 35% to 50%; the dehydrating agent is ammonium polyphosphate, ammonium borate, and trichloroethyl phosphate.

[0007] Furthermore, the carbon-forming agent is starch, pentaerythritol, dipentaerythritol, tripentaerythritol, and lignin; and the foaming agent is melamine, urea, urea-formaldehyde resin, dicyandiamide, and chlorinated paraffin.

[0008] Furthermore, the diffuse reflection material is titanium dioxide, barium sulfate, calcium sulfate, and calcium carbonate; the water repellent is polysiloxane powder, sodium methyl silicate, potassium methyl silicate, silane coupling agent, and hydrophobic silica.

[0009] Furthermore, the inorganic expansion material is expanded perlite, sodium aluminum silicate, calcium aluminum phosphate, and expanded graphite; and the inorganic flame retardant is aluminum hydroxide, magnesium hydroxide, and antimony oxide.

[0010] A method for preparing the fire-retardant coating as described above comprises the following process: water, a thickener, a dispersant and a defoaming agent are simultaneously added into a mixing tank, and after starting the motor, the materials are stirred evenly with the help of a stirring rod at the bottom; a dehydrating agent, a carbonizing agent, a foaming agent, a diffuse reflective material, a hydrophobic agent, an inorganic expansion material and an inorganic flame retardant are then added, and the stirring process is repeated until each material is stirred and dispersed; then the electric lifting rod at the bottom is started to control the downward movement of the discharge mechanism and open the top of the grinding gap, at which time the stirred material inside the mixing tank can be infiltrated into the grinding gap for grinding.

[0011] Furthermore, continuous grinding is performed at the bottom of the mixing tank until the raw materials inside are evenly dispersed and automatically discharged downward from the bottom of the discharge mechanism and fall into a discharge box at the bottom.

[0012] Furthermore, after the ground material is discharged, the electric lifting rod is controlled to rise again until the discharge mechanism is pressed against the top transmission plate, and the ground material is put into the mixing tank again, and the polymer emulsion is added to mix them thoroughly.

[0013] 9. The preparation method according to claim 8, characterized in that the mixed materials are directly discharged and packaged to form independent packaged products.

[0014] Furthermore, it also includes the process of discharging the processed paint and replacing the grinding assembly. In this process, the locking screw inside the grinding assembly is removed and the grinding column is directly pulled out from the bottom. At this time, after the discharge mechanism at the bottom is controlled to move downward, the finished product inside the mixing tank is directly discharged downward from the bottom of the discharge mechanism along the inclined bottom plate.

[0015] Beneficial effects of the present invention:

[0016] 1. The multifunctional intumescent tunnel fire retardant coating adopts water-based ultra-thin intumescent coating technology to replace the traditional non-intumescent thick fire retardant coating. It has excellent fire retardant performance, light weight, good safety performance, and has the advantages of green environmental protection, low usage, and convenient construction. The project adds brightening and energy-saving coating technology, which will effectively increase the light in the tunnel and contribute to the energy-saving and low-carbon goals. The project introduces hydrophobic self-cleaning topcoat technology to avoid dust and oil adhesion and play a self-cleaning function, thereby improving the tunnel's sanitation and air quality.

[0017] 2. This multifunctional intumescent tunnel fire retardant coating can improve the light reflectivity of the coating, improve the illumination and brightness of the tunnel. It can reduce the surface tension of the coating to obtain a super-hydrophobic, low-surface-energy self-cleaning coating with the advantages of low VOC, safety and environmental protection. It can be applied to the fire safety requirements of various tunnels such as highway tunnels, railway tunnels, and subway tunnels.

[0018] 3. The preparation method of the multifunctional intumescent tunnel fire retardant coating can complete the mixing process between each raw material by using a single mixing device, and after completing the preliminary mixing and dispersion, there is no need to take out the internal materials and they can be directly ground, which reduces the steps of transferring materials, thereby reducing equipment costs and avoiding external pollution, reducing equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of the method for preparing the fire retardant coating of the present invention;

[0020] Figure 2 is a structural diagram of a mixing device used in the preparation method of the present invention;

[0021] Figure 3 is a side sectional view of a mixing device of the present invention;

[0022] Figure 4 This is a diagram of the internal stirring structure of the mixing device of the present invention;

[0023] Figure 5 for Figure 3 A magnified image of area A;

[0024] In the figure: 1. mixing tank; 2. bottom plate; 3. discharge box; 4. support plate; 5. discharge mechanism; 6. motor; 7. drive shaft; 8. transmission plate; 9. grinding assembly; 10. electric lifting rod; 11. support plate; 12. enclosure sleeve; 13. grinding gap; 14. bending rod; 15. stirring rod; 16. positioning groove; 17. threaded hole; 18. grinding column; 19. groove; 20. locking screw; 21. fitting sleeve; 22. positioning column; 23. bottom plate. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0026] See also Figures 1 to 5 The present invention provides the following technical solution: a multifunctional intumescent tunnel fire retardant coating, which is composed of the following components in mass percentage: 10% to 50% polymer emulsion, 10% to 25% water, 10% to 35% dehydrating agent, 5% to 15% carbonizing agent, 8% to 18% foaming agent, 1% to 20% brightening filler, 1% to 20% hydrophobic agent, 0% to 10% inorganic expanding material, 0% to 10% inorganic flame retardant, 0% to 5% pigment, 0.1% to 0.5% thickener, 0.2% to 1% dispersant, and 0.2% to 1% defoaming agent.

[0027] In this embodiment, the polymer emulsion is pure acrylic emulsion, vinyl acetate emulsion, vinyl acetate acrylic emulsion, styrene acrylic emulsion, vinyl acetate-ethylene copolymer emulsion, and its solid content is 35% to 50%;

[0028] The dehydrating agent is ammonium polyphosphate, ammonium borate, or trichloroethyl phosphate;

[0029] The carbon-forming agent is starch, pentaerythritol, dipentaerythritol, tripentaerythritol, and lignin;

[0030] The foaming agent is melamine, urea, urea-formaldehyde resin, dicyandiamide, or chlorinated paraffin;

[0031] The diffuse reflection material is titanium dioxide, barium sulfate, calcium sulfate, and calcium carbonate;

[0032] The hydrophobic agent is polysiloxane powder, sodium methyl silicate, potassium methyl silicate, silane coupling agent, and hydrophobic silica;

[0033] The inorganic expansion material is expanded perlite, sodium aluminum silicate, calcium aluminum phosphate, and expanded graphite;

[0034] The inorganic flame retardant is aluminum hydroxide, magnesium hydroxide and antimony oxide.

[0035] This embodiment also provides the following specific component proportions, as shown in the following table:

[0036] Table 1 Specific composition ratio of fire retardant coating

[0037]

[0038] The fire retardant coating prepared according to the above materials and proportions was tested and its performance data was obtained as shown in the following table:

[0039] Table 2 Measured data of various properties of fire retardant coatings

[0040]

[0041]

[0042] After testing, the prepared tunnel coating has a high fire resistance limit. The fire resistance limit of the 1mm coating is more than 60min, the carbon layer expansion ratio is more than 10, and all performances meet the requirements of GB 14907-2002. The film-forming temperature and surface drying time of the selected aqueous emulsion should match the construction environment of the tunnel coating. A dense coating film should be formed when the water evaporates and dries, and a dense carbon layer should be formed when it burns and expands. The selected brightening filler can increase the light reflectivity of the coating and improve the illumination and brightness of the tunnel. The selected hydrophobic agent can reduce the surface tension of the coating to obtain a super-hydrophobic, low-surface-energy self-cleaning coating, thereby preventing dust and oil from adhering to the self-cleaning function. The present invention has the advantages of low VOC, safety and environmental protection, and has the characteristics of high strength of the foamed carbon layer and good thermal insulation and fireproof performance. It can be applied to the fire safety requirements of various tunnels such as highway tunnels, railway tunnels, and subway tunnels.

[0043] The present embodiment also provides a method for preparing the fire-retardant coating as described above, comprising the following process: simultaneously adding water and a thickener, a dispersant, and a defoaming agent into a mixing tank 1, starting a motor 6, and stirring the materials evenly with the help of a stirring rod at the bottom; then adding a dehydrating agent, a carbonizing agent, a foaming agent, a diffuse reflective material, a hydrophobic agent, an inorganic expansion material, and an inorganic flame retardant, and repeating the above stirring process until each material is stirred and dispersed; then starting the electric lifting rod 10 at the bottom, controlling the discharge mechanism 5 to move downward, and opening the top of the grinding gap 13, at which time the material after stirring inside the mixing tank 1 can be introduced into the grinding gap 13 for grinding.

[0044] In this embodiment, a mixing device is used, which includes a mixing tank 1, a bottom plate 23, a discharge box 3, a support plate 4, and a discharge mechanism 5. The mixing tank 1 is welded to the bottom plate 23 through the bottom plate 23 and the support plate 4. A motor 6 is screwed on the top of the mixing tank 1, and a drive shaft 7 is inserted into the output end of the motor 6. A transmission plate 8 is integrally formed at the end of the drive shaft 7. A bending rod 14 is welded to the side of the transmission plate 8, and a stirring rod 15 is integrally formed at the end of the bending rod 14. The bottom plate 23 is welded to the bottom of the mixing tank 1, and the middle position of the bottom plate 23 is tilted downward.

[0045] The grinding is continued at the bottom of the mixing tank 1 until the raw materials inside are evenly dispersed and automatically discharged downward from the bottom of the discharge mechanism 5 and fall into the discharge box 3 at the bottom. After the ground materials are discharged, the electric lifting rod 10 is controlled to rise again until the discharge mechanism 5 is pressed against the transmission plate 8 at the top, and the ground materials are put into the mixing tank 1 again, and the polymer emulsion is added to mix them fully. After the mixing is completed, the materials are directly discharged and packaged to form independent packaged products.

[0046] In this embodiment, a replaceable grinding assembly 9 is used, and the grinding assembly 9 includes a grinding column 18 and a locking screw 20. A positioning column 22 is integrally formed on the top of the grinding column 18. A threaded hole 17 and a positioning groove 16 are provided at the bottom of the transmission plate 8. The top of the threaded column is embedded in the threaded hole 17, and the top of the grinding column 18 is embedded in the positioning groove 16 through the positioning column 22. A retaining sleeve 12 is provided in the middle of the discharging mechanism 5, and a grinding gap 13 is provided between the retaining sleeve 12 and the side of the grinding column 18. A groove 19 is provided at the bottom of the grinding column 18, and the threaded column penetrates from the inside of the groove 19 to the middle position of the grinding column 18.

[0047] In this embodiment, the processed paint is discharged and the grinding component 9 is replaced. In this process, the locking screw 20 inside the grinding component 9 is removed, and the grinding column 18 is directly pulled out from the bottom. At this time, after the discharge mechanism 5 at the bottom is controlled to move downward, the finished product inside the mixing tank 1 is directly discharged downward from the bottom of the discharge mechanism 5 along the inclined bottom plate 23.

[0048] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

[0049] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A multifunctional intumescent tunnel fire retardant coating, characterized in that: Calculated in percentage by mass, it is composed of the following ingredients: 10% to 50% polymer emulsion, 10% to 25% water, 10% to 35% dehydrating agent, 5% to 15% carbonizing agent, 8% to 18% foaming agent, 1% to 20% brightening filler, 1% to 20% hydrophobic agent, 0% to 10% inorganic expanding material, 0% to 10% inorganic flame retardant, 0% to 5% pigment, 0.1% to 0.5% thickener, 0.2% to 1% dispersant and 0.2% to 1% defoaming agent.

2. The multifunctional intumescent tunnel fire retardant coating according to claim 1, characterized in that: The polymer emulsion is pure acrylic emulsion, vinyl acetate emulsion, vinyl acetate acrylic emulsion, styrene acrylic emulsion, vinyl acetate-ethylene copolymer emulsion, and its solid content is 35% to 50%; the dehydrating agent is ammonium polyphosphate, ammonium borate, and trichloroethyl phosphate.

3. The multifunctional intumescent tunnel fire retardant coating according to claim 1, characterized in that: The carbonizing agent is starch, pentaerythritol, dipentaerythritol, tripentaerythritol and lignin; the foaming agent is melamine, urea, urea-formaldehyde resin, dicyandiamide and chlorinated paraffin.

4. The multifunctional intumescent tunnel fire retardant coating according to claim 1, characterized in that: The diffuse reflection material is titanium dioxide, barium sulfate, calcium sulfate, and calcium carbonate; the water repellent is polysiloxane powder, sodium methyl silicate, potassium methyl silicate, silane coupling agent, and hydrophobic silicon dioxide.

5. The multifunctional intumescent tunnel fire retardant coating according to claim 1, characterized in that: The inorganic expansion material is expanded perlite, sodium aluminum silicate, calcium aluminum phosphate, and expanded graphite; the inorganic flame retardant is aluminum hydroxide, magnesium hydroxide, and antimony oxide.

6. A method for preparing the fire retardant coating according to claim 1, characterized in that: The method includes the following steps: adding water and thickener, dispersant and defoamer into the mixing tank at the same time, starting the motor and stirring the materials evenly with the help of the stirring rod at the bottom; then adding dehydrating agent, carbonizing agent, foaming agent, diffuse reflective material, hydrophobic agent, inorganic expansion material and inorganic flame retardant, and repeating the above stirring process until each material is stirred and dispersed; then starting the electric lifting rod at the bottom, controlling the discharge mechanism to move downward, and opening the top of the grinding gap, at which time the stirred materials in the mixing tank can be infiltrated into the grinding gap for grinding.

7. The preparation method according to claim 6, characterized in that: The grinding is continued at the bottom of the mixing tank until the raw materials inside are evenly dispersed and automatically discharged downward from the bottom of the discharge mechanism and fall into the discharge box at the bottom.

8. The preparation method according to claim 7, characterized in that: After the ground material is discharged, the electric lifting rod is controlled to rise again until the discharge mechanism is pressed against the transmission plate at the top, and the ground material is put into the mixing tank again, and the polymer emulsion is added to mix it thoroughly.

9. The preparation method according to claim 8, characterized in that: The mixed materials are directly discharged and packaged to form independent packaged products.

10. The preparation method according to claim 6, characterized in that: It also includes the process of discharging the processed paint and replacing the grinding assembly. In this process, the locking screw inside the grinding assembly is removed to directly pull the grinding column out from the bottom. At this time, the discharge mechanism at the bottom is controlled to move downward, and the finished product inside the mixing tank is directly discharged downward from the bottom of the discharge mechanism along the inclined bottom plate.

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