Flame-retardant antifouling organic-inorganic composite coating for underground coal mine roadway and preparation method of flame-retardant antifouling organic-inorganic composite coating

Abstract

The invention discloses a flame-retardant antifouling organic-inorganic composite coating for an underground coal mine roadway and a preparation method of the flame-retardant antifouling organic-inorganic composite coating, and relates to the technical field of composite coatings. When the flame-retardant antifouling organic-inorganic composite coating for the underground coal mine roadway is prepared, inorganic filler is soaked in conductive slurry to prepare modified inorganic filler; the modified polyurethane emulsion, the calcined wollastonite powder, the modified inorganic filler and water glass are mixed with water and then coated, and the flame-retardant antifouling organic-inorganic composite coating for the underground coal mine roadway is prepared after curing. The prepared flame-retardant antifouling organic-inorganic composite coating for the underground coal mine roadway has the advantages of flame retardance, static electricity resistance, stain resistance, super-hydrophobicity, moisture resistance, wear resistance, high bonding strength and high tensile strength. And the coating has good brightness, can improve the sight condition of underground work, and changes the overall dark environment of an underground roadway.

Description

Technical Field

[0001] The present invention relates to the technical field of composite coatings, in particular to a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels and a preparation method thereof. Background Art

[0002] Gas disasters are among the most detrimental accidents in coal mining. During the mining process, gas is slowly and continuously released from the coal seam and surrounding rock. In poor ventilation, its concentration increases. Gas concentrations between 5% and 16% can trigger explosions and disasters when exposed to blasting sparks, electrical sparks, friction and impact sparks, static electricity, or spontaneous combustion of coal. Gas explosions have become a major obstacle to the coal industry's development into a safe, efficient, and technology-intensive industry. To prevent these explosions, in addition to improving ventilation and reducing gas concentrations, static electricity control is also crucial.

[0003] Coal mine fires are another major threat to coal mine safety. Underground coal mines are highly susceptible to fires, and these fires have a significant impact on coal mine safety. Coal mines contain a large number of combustible materials, such as coal, gas, coal dust, pit wood, fuel, explosives, and various types of mechanical and electrical equipment, making them highly susceptible to fire. Once a fire breaks out, it can impact safety at best, but can also destroy coal resources, materials, and equipment, causing casualties, and even triggering gas and coal dust explosions.

[0004] Water seepage is a common phenomenon in underground coal mines, impacting production and management. During mining and excavation, water continuously seeps from the coal seam and surrounding rock into the mining face and tunnels. This seepage is characterized by widespread, prolonged, and slow flow. This seepage creates humidity underground, impacting environmental conditions and production efficiency. It also requires constant drainage, increasing production costs. Mine water also has a corrosive effect, causing rust on various metal equipment, rails, and supports, shortening their service life.

[0005] In recent years, coating materials have been used in underground coal mines to help address these issues. These materials, sprayed onto the surfaces of tunnels, goafs, or coal rock masses, are required to be waterproof, moisture-proof, bright, fireproof, and antistatic. They must also be flame-retardant and prevent water seepage and gas spillage from the coal walls. However, currently used coatings lack adequate impermeability, flame retardancy, and antistatic properties. Furthermore, the coatings' poor glossiness prevents the overall darkness of the underground tunnels. Furthermore, when sprayed onto cement mortar, concrete, and masonry surfaces, they exhibit poor adhesion and are prone to peeling. Summary of the Invention

[0006] The purpose of the present invention is to provide a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels and a preparation method thereof, so as to solve the problems existing in the prior art.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: A flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels, wherein the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels is prepared by mixing modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, and water glass with water, and then coating the mixture and curing the mixture. The modified polyurethane emulsion is prepared by reacting isophorone diisocyanate with polytetramethylene ether glycol and hydroxyl-terminated fluorosilicone oil, then reacting with a chain extender, and finally reacting with iodomethane and then adding water; The chain extender includes 3-dimethylamino-1,2-propylene glycol and a flame retardant chain extender; The flame retardant chain extender is prepared by reacting triglycidyl isocyanurate with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide; The modified inorganic filler is prepared by immersing the inorganic filler in a conductive paste; The conductive paste is prepared by mixing modified polyacrylic acid binder, graphene oxide and water; The modified polyacrylic acid adhesive is prepared by copolymerizing acrylic acid, acrylonitrile and acrylamide.

[0008] As an optimization, the inorganic filler includes titanium dioxide, silica powder, and mica.

[0009] A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels comprises the following preparation steps: (1) By weight, 2-3 parts of triglycidyl isocyanurate, 4.97-7.45 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 35-40 parts of tetrahydrofuran were mixed evenly, stirred and refluxed at 65-70°C and 200-300 r / min for 2-2.5 hours, the solvent was removed by rotary evaporation, and vacuum dried at 50-60°C for 10-12 hours to prepare a flame retardant chain extender; (2) According to the mass fraction, 10-15 parts of polytetramethylene ether glycol, 5-6 parts of hydroxyl-terminated fluorosilicone oil, and 25-30 parts of N,N-dimethylformamide were weighed and mixed evenly. Under nitrogen atmosphere, the temperature was raised to 70-75°C. Isophorone diisocyanate was added at a molar ratio of isocyanate group to hydroxyl group of 1: (0.58-0.66). 0.12-0.15 parts of dibutyltin dilaurate were added. The mixture was reacted at 250-350 r / min for 1.5-2 hours. After sampling to confirm the complete reaction, the temperature was lowered to 50-55°C. 3-dimethylamino-1,2-propylene glycol was added at a molar ratio of the remaining isocyanate group to the hydroxyl group of 1: (0.7-0.75). The mixture was reacted for 1.5 to 2 hours. After sampling to confirm the complete reaction, a flame retardant chain extender was added at a molar ratio of the remaining isocyanate group to the hydroxyl group of (1 to 1.1):1, and the mixture was reacted at 70 to 80°C and 300 to 400 r / min for 2 to 3 hours. After sampling to confirm the complete reaction, iodomethane was added at a molar ratio of 3-dimethylamino-1,2-propylene glycol to iodomethane of 1:(0.7 to 0.8), and the mixture was reacted at 25 to 30°C and 300 to 400 r / min for 1.5 to 2 hours. N,N-dimethylformamide was removed by distillation under reduced pressure, 55 to 75 parts of pure water was added, and the mixture was stirred at a high speed of 1500 to 2000 r / min for 40 to 50 minutes to obtain a modified polyurethane emulsion. (3) By weight, in an argon atmosphere, 7-8 parts of acrylic acid and 75-80 parts of pure water were mixed evenly in an ice-water bath, and the pH was adjusted to 7 with a 0.1 mol / L sodium hydroxide aqueous solution. After the temperature dropped to room temperature, 2-3 parts of acrylonitrile and 4-5 parts of acrylamide were added, and the mixture was stirred at 200-250 r / min for 10-15 min at room temperature. 0.1-0.12 parts of ammonium persulfate were added, and the mixture was reacted at 60-70°C and 200-250 r / min for 6-7 h. After the reaction was completed, the mixture was naturally cooled to room temperature, freeze-dried, ground, and washed with anhydrous ethanol at 200-300 r / min for 5-6 h at room temperature. The mixture was filtered and the mixture was repeated 3-4 times. The mixture was vacuum-dried at 50-60°C for 10-12 h to obtain a modified polyacrylic acid binder. (4) By weight, 1.5-2.5 parts of modified polyacrylic acid binder and 75-85 parts of pure water were mixed evenly, stirred at 200-300 r / min for 15-20 min at room temperature, 4-5 parts of graphene oxide were added, stirred at 800-1000 r / min for 60-80 min at room temperature, and then homogenized at 100-120 MPa to obtain a conductive slurry, and then the inorganic filler was impregnated into the conductive slurry at a material-liquid ratio of 1:(15-20) g / ml, stirred at 50-70 r / min for 30-40 min at room temperature, taken out and drained, and dried in an oven at 60-70 °C for 24-26 h to obtain a modified inorganic filler; (5) According to the mass ratio, 20 parts of modified polyurethane emulsion and 10 parts of water were mixed evenly, and stirred at 300-400 r / min for 2-3 minutes. 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 5-6 parts of water glass were added and mixed evenly, and stirred at 600-800 r / min for 5-7 minutes. The mixture was allowed to stand for 2-3 minutes and then coated on the base surface. The mixture was cured at 21-25°C and 45% RH-70% RH for 168 hours to obtain a flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels.

[0010] As an optimization, the reaction process of the flame retardant chain extender in step (1) is as follows: .

[0011] As an optimization, in the inorganic filler of step (4), the mass ratio of titanium dioxide, silica powder and mica is 1:(0.4~0.5):(0.5~0.75).

[0012] As an optimization, the calcined wollastonite powder in step (5) is obtained by calcining the wollastonite powder at 900-1100° C. in an air atmosphere for 2 h, grinding the powder, and passing it through a 325-mesh sieve.

[0013] As an optimization, the water glass in step (5) is Na2O·nSiO2, with a modulus of 1.2 and an alkali equivalent of 10%.

[0014] As an optimization, the coating in step (5) can be spraying, scraping, brushing or rolling.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The invention prepares a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels. First, triglycidyl isocyanurate is reacted with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide to prepare a flame retardant chain extender; isophorone diisocyanate is reacted with polytetramethylene ether glycol and hydroxyl-terminated fluorosilicone oil, and then with 3-dimethylamino-1,2-propylene glycol and the flame retardant chain extender; finally, the reaction is carried out with methyl iodide and then added. A modified polyurethane emulsion is prepared by adding water; acrylic acid, acrylonitrile and acrylamide are copolymerized to prepare a modified polyacrylic acid binder; the modified polyacrylic acid binder and graphene oxide are mixed with water to prepare a conductive paste, and then an inorganic filler is immersed in the conductive paste to prepare a modified inorganic filler; the modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler and water glass are mixed with water and then scraped and applied, and after curing, a flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels is prepared.

[0016] First, the epoxy group on triglycidyl isocyanurate reacts with the hydroxyl group on 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide to obtain a flame retardant chain extender containing a large number of phosphorus and nitrogen flame retardant elements. After the reaction, the flame retardant chain extender contains multiple hydroxyl groups and can be used as a polyurethane chain extender. The introduction of a large number of rigid rings can improve the mechanical properties of the polyurethane chain segments and the supporting capacity of the polymer network in the coating, thereby improving the mechanical properties of the coating. The introduction of a large number of flame retardant elements can effectively improve the flame retardant properties; isophorone diisocyanate first reacts with polytetramethylene ether diol and hydroxyl-terminated fluorosilicone oil, then reacts with 3-dimethylamino-1,2-propylene glycol and the flame retardant chain extender, and finally reacts with iodomethane. The hydroxyl-terminated fluorosilicone oil contains fluorinated polysiloxane chains, which undergo microphase separation and move to the outer surface due to the difference in surface energy during the curing process, thereby obtaining a superhydrophobic material. The outer surface of the polyurethane can effectively improve the anti-fouling ability and anti-permeation performance. It also contains a large amount of flame retardant element silicon, which can form a synergistic flame retardant effect with the flame retardant elements phosphorus and nitrogen in the flame retardant chain extender, thereby greatly improving the flame retardant performance; 3-dimethylamino-1,2-propylene glycol in the polyurethane segment is a chain extender with a tertiary amine group, a part of which reacts with methyl iodide to form a quaternary ammonium cation. The quaternary ammonium cation is a hydrophilic group, which allows the synthesized polyurethane to form an emulsion in water. At the same time, the quaternary ammonium cation distributed on the entire polyurethane segment can also exist as a conductive path, thereby improving the antistatic performance. The other part of the tertiary amine group remains the same, which can form a firm connection with the substrate, calcined wollastonite powder and filler in the coating through hydrogen bonds, electrostatic effects, etc., on the one hand improving the mechanical properties of the coating, on the other hand also improving the bonding strength, so that it can firmly adhere to the tunnel wall surface and is not easy to fall off, thereby extending the service life.

[0017] Secondly, acrylic acid, acrylonitrile and acrylamide are copolymerized to prepare a modified polyacrylic acid binder, wherein acrylic acid and acrylamide act as viscosity providers, providing viscosity through electrostatic, hydrogen bonding, complexation and the like, and polar groups in acrylonitrile and acrylamide, such as nitrile and amide groups, provide electrical conductivity, which can better assist in improving antistatic properties. After the modified polyacrylic acid binder is compounded with graphene oxide into a conductive slurry, it is coated on the surface of an inorganic filler by an impregnation method, thereby forming a conductive layer on the surface of the inorganic filler. This method effectively circumvents the problem of difficult dispersion of graphene oxide in the coating matrix, and avoids the problem of performance degradation caused by agglomeration of graphene oxide in the coating matrix. Through the conductive layer on the surface of the inorganic filler, it exists as a node in the conductive network.

[0018] Finally, the modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, and water glass are mixed and then scraped to form a coating. The modified polyurethane emulsion provides good adhesion, supporting performance, surface hydrophobic and anti-fouling properties, flame retardant properties and antistatic properties. At the same time, the modified inorganic filler is used as a conductive node, and the polymer network formed by the modified polyurethane emulsion is used as a conductive path, thereby forming a three-dimensional conductive network in the coating, which greatly improves the antistatic performance. The polyurethane segment with silane chain segment has a more compact structure, and with the help of the water-repellent properties of silane and fluorine segments, it also has good waterproof and anti-permeability properties. The calcined wollastonite powder can undergo hydration reaction and gelation under the action of water glass, thereby forming a tighter structure. Titanium dioxide with a high refractive index is also added to the filler. Its high refractive index can effectively reflect light, thereby increasing brightness and improving the dark environment of underground tunnels. It can be effectively used in the underground tunnel environment of coal mines. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] The raw materials used in all the following examples and comparative examples are as follows: Polytetramethylenetetrahydrofuran ether glycol: model is PTMEG T-1000, weight average molecular weight is 1000, purchased from Hangzhou Weitong Nanomaterial Co., Ltd. Hydroxyl-terminated fluorosilicone oil: model NFS7200, weight-average molecular weight 1000, purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd. Graphene oxide: Model XFSG01, purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd. Wollastonite powder: ultrafine wollastonite powder, particle size 1250 mesh, purchased from Jiangxi Chenxin New Materials Co., Ltd. Inorganic filler: the mass ratio of titanium dioxide, silica fume and mica is 1:0.45:0.6; Titanium dioxide: model R-982, purchased from Longbai Sichuan Titanium Industry Co., Ltd. Silicon powder: Product number Si0343251000, purchased from Beijing Juguang Evonik Technology Co., Ltd. Mica: Mica powder, particle size 50 mesh, was purchased from Lingshou County Shunyong Mineral Products Co., Ltd.

[0021] The calcined wollastonite powder used in the following examples and comparative examples was obtained by calcining wollastonite powder at 1000° C. in air atmosphere for 2 hours, grinding the powder, and passing it through a 325-mesh sieve.

[0022] Example 1: A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels, the method comprising the following preparation steps: (1) By weight, 2 parts of triglycidyl isocyanurate, 4.97 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 35 parts of tetrahydrofuran were mixed evenly, stirred and refluxed at 65°C and 200 r / min for 2.5 hours, the solvent was removed by rotary evaporation, and vacuum dried at 50°C for 12 hours to prepare a flame retardant chain extender; (2) According to the mass percentage, 10 parts of polytetramethylene glycol, 5 parts of hydroxyl-terminated fluorosilicone oil, and 25 parts of N,N-dimethylformamide were weighed and mixed evenly. Under nitrogen atmosphere, the temperature was raised to 70°C, and isophorone diisocyanate was added at a molar ratio of isocyanate group to hydroxyl group of 1:0.58. 0.12 parts of dibutyltin dilaurate were added. The mixture was reacted at 250 r / min for 2 hours. After sampling to confirm the complete reaction, the temperature was lowered to 50°C, and 3-dimethylamino-1,2-propanediol was added at a molar ratio of the remaining isocyanate group to the hydroxyl group of 1:0.7. alcohol, react for 1.5 hours, take samples to confirm the complete reaction, add a flame retardant chain extender at a molar ratio of 1:1 between the remaining isocyanate group and the hydroxyl group, react at 70°C, 300r / min for 3 hours, take samples to confirm the complete reaction, add iodomethane at a molar ratio of 1:0.7 between 3-dimethylamino-1,2-propylene glycol and iodomethane, react at 25°C, 300r / min for 2 hours, remove N,N-dimethylformamide by distillation under reduced pressure, add 55 parts of pure water, and stir at a high speed of 1500r / min for 50 minutes to obtain a modified polyurethane emulsion; (3) In an argon atmosphere, 7 parts of acrylic acid and 75 parts of pure water were mixed uniformly in an ice-water bath, and the pH was adjusted to 7 with a 0.1 mol / L sodium hydroxide aqueous solution. After the temperature dropped to room temperature, 2 parts of acrylonitrile and 4 parts of acrylamide were added. The mixture was stirred at 200 r / min for 15 min at room temperature. 0.1 parts of ammonium persulfate was added and the mixture was reacted at 60°C and 200 r / min for 7 h. After the reaction was completed, the mixture was naturally cooled to room temperature, freeze-dried, ground, and washed with anhydrous ethanol at 200 r / min for 6 h at room temperature. The mixture was filtered and the mixture was repeated 3 times. The mixture was vacuum-dried at 50°C for 12 h to obtain a modified polyacrylic acid binder. (4) 1.5 parts of modified polyacrylic acid binder and 75 parts of pure water were mixed uniformly by weight, stirred at 200 r / min for 20 min at room temperature, 4 parts of graphene oxide were added, stirred at 800 r / min for 80 min at room temperature, and then homogenized at 100 MPa high pressure to obtain a conductive slurry, and then the inorganic filler was impregnated into the conductive slurry at a material-liquid ratio of 1:15 g / ml, stirred at 50 r / min for 40 min at room temperature, taken out and drained, and dried in an oven at 60°C for 26 h to obtain a modified inorganic filler; (5) According to the mass ratio, 20 parts of modified polyurethane emulsion and 10 parts of water were mixed evenly, stirred at 300 r / min for 3 minutes, 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 5 parts of water glass were added and mixed evenly, stirred at 600 r / min for 7 minutes, allowed to stand for 3 minutes, sprayed on the base surface, and cured at 21 ° C and 45% RH for 168 hours to obtain a flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels.

[0023] Example 2: A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels, the method comprising the following preparation steps: (1) By weight, 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran were mixed evenly, stirred and refluxed at 65°C and 250 r / min for 2 h, the solvent was removed by rotary evaporation, and vacuum dried at 55°C for 11 h to prepare a flame retardant chain extender; (2) According to the mass percentage, 12.5 parts of polytetramethylene ether glycol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide were weighed and mixed evenly. Under nitrogen atmosphere, the temperature was raised to 72°C, and isophorone diisocyanate was added at a molar ratio of isocyanate group to hydroxyl group of 1:0.63. 0.135 parts of dibutyltin dilaurate were added. The mixture was reacted at 300 r / min for 1.5 hours. After sampling to confirm the complete reaction, the temperature was lowered to 55°C, and 3-dimethylamino-1,2-propanediol was added at a molar ratio of the remaining isocyanate group to the hydroxyl group of 1:0.72. alcohol, react for 1.5 hours, take samples to confirm the complete reaction, add a flame retardant chain extender at a molar ratio of residual isocyanate group to hydroxyl group of 1.05:1, react at 75°C, 350r / min for 2.5 hours, take samples to confirm the complete reaction, add iodomethane at a molar ratio of 3-dimethylamino-1,2-propylene glycol to iodomethane of 1:0.75, react at 28°C, 350r / min for 1.5 hours, remove N,N-dimethylformamide by reduced pressure distillation, add 65 parts of pure water, and stir at a high speed of 1800r / min for 45 minutes to obtain a modified polyurethane emulsion; (3) In an argon atmosphere, 7.5 parts of acrylic acid and 78 parts of pure water were mixed uniformly in an ice-water bath, and the pH was adjusted to 7 with a 0.1 mol / L sodium hydroxide aqueous solution. After the temperature dropped to room temperature, 2.5 parts of acrylonitrile and 4.5 parts of acrylamide were added, and the mixture was stirred at 225 r / min at room temperature for 12 min. 0.11 parts of ammonium persulfate were added, and the mixture was reacted at 65°C and 225 r / min for 6.5 h. After the reaction was completed, the mixture was naturally cooled to room temperature, freeze-dried, ground, and washed with anhydrous ethanol at 250 r / min at room temperature for 5.5 h. The mixture was filtered and the mixture was repeated 3 times. The mixture was vacuum-dried at 55°C for 11 h to obtain a modified polyacrylic acid binder. (4) 2 parts of modified polyacrylic acid binder and 80 parts of pure water were mixed uniformly by weight, stirred at 250 r / min for 18 min at room temperature, 4.5 parts of graphene oxide were added, stirred at 900 r / min for 70 min at room temperature, and then homogenized at 110 MPa to obtain a conductive slurry. Subsequently, the inorganic filler was impregnated into the conductive slurry at a material-liquid ratio of 1:18 g / ml, stirred at 60 r / min for 35 min at room temperature, taken out and drained, and dried in an oven at 65°C for 25 h to obtain a modified inorganic filler; (5) According to the mass ratio, 20 parts of modified polyurethane emulsion and 10 parts of water were mixed evenly, stirred at 350 r / min for 2.5 min, 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 5.5 parts of water glass were added and mixed evenly, stirred at 700 r / min for 6 min, allowed to stand for 2.5 min, sprayed on the base surface, and cured at 23 ° C and 55% RH for 168 h to obtain a flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels.

[0024] Example 3: A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels, the method comprising the following preparation steps: (1) By weight, 3 parts of triglycidyl isocyanurate, 7.45 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 40 parts of tetrahydrofuran were mixed evenly, stirred and refluxed at 70°C and 300 r / min for 2 h, the solvent was removed by rotary evaporation, and vacuum dried at 60°C for 10 h to prepare a flame retardant chain extender; (2) According to the mass percentage, 15 parts of polytetramethylene glycol, 6 parts of hydroxyl-terminated fluorosilicone oil, and 30 parts of N,N-dimethylformamide were weighed and mixed evenly. Under nitrogen atmosphere, the temperature was raised to 75°C, and isophorone diisocyanate was added at a molar ratio of isocyanate group to hydroxyl group of 1:0.66. 0.15 parts of dibutyltin dilaurate were added and the reaction was carried out at 350 r / min for 1.5 hours. After sampling to confirm the complete reaction, the temperature was lowered to 55°C, and 3-dimethylamino-1,2-propanediol was added at a molar ratio of the remaining isocyanate group to the hydroxyl group of 1:0.75. alcohol, react for 2 hours, take samples to confirm the complete reaction, add a flame retardant chain extender at a molar ratio of residual isocyanate group to hydroxyl group of 1.1:1, react at 80°C, 400r / min for 2 hours, take samples to confirm the complete reaction, add iodomethane at a molar ratio of 3-dimethylamino-1,2-propylene glycol to iodomethane of 1:0.8, react at 30°C, 400r / min for 1.5 hours, remove N,N-dimethylformamide by reduced pressure distillation, add 75 parts of pure water, and stir at a high speed of 2000r / min for 40 minutes to obtain a modified polyurethane emulsion; (3) In an argon atmosphere, 8 parts of acrylic acid and 80 parts of pure water were mixed uniformly in an ice-water bath, and the pH was adjusted to 7 with a 0.1 mol / L sodium hydroxide aqueous solution. After the temperature dropped to room temperature, 3 parts of acrylonitrile and 5 parts of acrylamide were added, and the mixture was stirred at 250 r / min for 10 min at room temperature. 0.12 parts of ammonium persulfate were added, and the mixture was reacted at 70°C and 250 r / min for 6 h. After the reaction was completed, the mixture was naturally cooled to room temperature, freeze-dried, ground, and washed with anhydrous ethanol at 300 r / min for 5 h at room temperature. The mixture was filtered and the mixture was repeated 4 times. The mixture was vacuum-dried at 60°C for 10 h to obtain a modified polyacrylic acid binder. (4) 2.5 parts of modified polyacrylic acid binder and 85 parts of pure water were mixed uniformly by weight, stirred at 300 r / min for 15 min at room temperature, 5 parts of graphene oxide were added, stirred at 1000 r / min for 60 min at room temperature, and then homogenized at 120 MPa to obtain a conductive slurry. Subsequently, the inorganic filler was impregnated into the conductive slurry at a material-liquid ratio of 1:20 g / ml, stirred at 70 r / min for 30 min at room temperature, taken out and drained, and dried in an oven at 70°C for 24 h to obtain a modified inorganic filler; (5) By mass, 20 parts of modified polyurethane emulsion and 10 parts of water were mixed evenly, stirred at 400 r / min for 2 minutes, 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 6 parts of water glass were added and mixed evenly, stirred at 800 r / min for 5 minutes, allowed to stand for 2 minutes, sprayed on the base surface, and cured at 25 ° C and 70% RH for 168 hours to obtain a flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels.

[0025] Comparative Example 1: The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 1 and Example 2 lies in the difference in step (1). Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are mixed uniformly by mass, and the mixture is stirred and refluxed at 65°C and 250 r / min for 1 hour. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 hours to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0026] Comparative Example 2: The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 2 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are mixed uniformly by mass, stirred and refluxed at 65°C and 250 r / min for 1.5 hours, the solvent is removed by rotary evaporation, and vacuum drying is performed at 55°C for 11 hours to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0027] Comparative Example 3: The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 3 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are mixed uniformly by mass, stirred and refluxed at 65°C and 250 r / min for 3 hours, the solvent is removed by rotary evaporation, and vacuum drying is performed at 55°C for 11 hours to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0028] Comparative Example 4: The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 4 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are uniformly mixed, stirred and refluxed at 65°C and 250 r / min for 3.5 hours, the solvent is removed by rotary evaporation, and vacuum drying is performed at 55°C for 11 hours to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0029] Comparative Example 5: The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 5 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are uniformly mixed, stirred and refluxed at 50°C and 250 r / min for 2 hours, the solvent is removed by rotary evaporation, and vacuum drying is performed at 55°C for 11 hours to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0030] Comparative Example 6: The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 6 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are mixed uniformly by mass, stirred and refluxed at 55°C and 250 r / min for 2 h, the solvent is removed by rotary evaporation, and vacuum drying is performed at 55°C for 11 h to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0031] Comparative Example 7: The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 7 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are uniformly mixed, stirred and refluxed at 80°C and 250 r / min for 2 h, the solvent is removed by rotary evaporation, and vacuum drying is performed at 55°C for 11 h to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0032] Comparative Example 8: The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 8 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: 2.5 parts of triglycidyl isocyanurate, 6.21 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 38 parts of tetrahydrofuran are mixed uniformly by mass, stirred and refluxed at 85°C and 250 r / min for 2 h, the solvent is removed by rotary evaporation, and vacuum drying is performed at 55°C for 11 h to prepare a flame retardant chain extender. The remaining steps are the same as those in Example 2.

[0033] Comparative Example 9: The preparation method of the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 9 is different from that in Example 2 in that step (1) is not performed, and step (2) is modified as follows: 12.5 parts of polytetramethylene ether glycol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide are weighed and mixed uniformly in parts by mass; the mixture is heated to 72°C under a nitrogen atmosphere; isophorone diisocyanate is added at a molar ratio of isocyanate group to hydroxyl group of 1:0.63; 0.135 parts of dibutyltin dilaurate are added; the mixture is reacted at 300 r / min for 1.5 hours; after sampling to confirm that the reaction is complete, the mixture is cooled to 55°C; the mixture is heated ... 3-dimethylamino-1,2-propylene glycol was added at a molar ratio of 1:0.72 to hydroxyl groups, and the reaction was continued for 1.5 hours. After sampling to confirm the complete reaction, ethylene glycol was added at a molar ratio of 1.05:1 to the remaining isocyanate groups and hydroxyl groups, and the reaction was continued at 75°C and 350 r / min for 2.5 hours. After sampling to confirm the complete reaction, iodomethane was added at a molar ratio of 1:0.75 to 3-dimethylamino-1,2-propylene glycol and iodomethane, and the reaction was continued at 28°C and 350 r / min for 1.5 hours. N,N-dimethylformamide was removed by distillation under reduced pressure, 65 parts of pure water was added, and the mixture was stirred at 1800 r / min for 45 minutes to obtain a modified polyurethane emulsion. The remaining steps were the same as those in Example 2.

[0034] Comparative Example 10: The difference between the preparation method of the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 10 and Example 2 lies in the difference in step (2). Step (2) is modified as follows: 18 parts of polytetramethylene glycol and 28 parts of N,N-dimethylformamide are weighed and mixed uniformly in parts by mass. Under a nitrogen atmosphere, the temperature is raised to 72°C, isophorone diisocyanate is added at a molar ratio of isocyanate group to hydroxyl group of 1:0.63, 0.135 parts of dibutyltin dilaurate are added, the reaction speed is 300r / min, the reaction is carried out for 1.5h, sampling is performed to confirm the complete reaction, the temperature is lowered to 55°C, and the molar ratio of the remaining isocyanate group to the hydroxyl group is 0. 3-Dimethylamino-1,2-propylene glycol was added at a molar ratio of 1:0.72, and the reaction was continued for 1.5 hours. After sampling to confirm the complete reaction, a flame retardant chain extender was added at a molar ratio of residual isocyanate groups to hydroxyl groups of 1.05:1, and the reaction was continued at 75°C and 350 rpm for 2.5 hours. After sampling to confirm the complete reaction, iodomethane was added at a molar ratio of 3-dimethylamino-1,2-propylene glycol to iodomethane of 1:0.75, and the reaction was continued at 28°C and 350 rpm for 1.5 hours. N,N-dimethylformamide was removed by distillation under reduced pressure, and 65 parts of pure water was added. The mixture was stirred at a high speed of 1800 rpm for 45 minutes to produce a modified polyurethane emulsion. The remaining steps were the same as those in Example 2.

[0035] Comparative Example 11: The difference between the preparation method of the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 11 and Example 2 lies in the difference in step (2). Step (2) is modified as follows: 12.5 parts of polytetramethylene ether glycol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide are weighed and mixed uniformly in parts by mass. Under a nitrogen atmosphere, the temperature is raised to 72°C, isophorone diisocyanate is added at a molar ratio of isocyanate group to hydroxyl group of 1:0.63, 0.135 parts of dibutyltin dilaurate are added, and the reaction is carried out at 300r / min for 1.5 seconds. h, sampling was performed to confirm complete reaction, and the temperature was lowered to 55° C. 3-dimethylamino-1,2-propylene glycol was added at a molar ratio of residual isocyanate groups to hydroxyl groups of 1:0.72, and the reaction was continued for 1.5 h. After sampling was performed to confirm complete reaction, a flame retardant chain extender was added at a molar ratio of residual isocyanate groups to hydroxyl groups of 1.05:1, and the reaction was continued at 75° C. and 350 rpm for 2.5 h. After sampling was performed to confirm complete reaction, N,N-dimethylformamide was removed by vacuum distillation, 65 parts of pure water was added, and the mixture was stirred at a high speed of 1800 rpm for 45 min to produce a modified polyurethane emulsion. The remaining steps were the same as in Example 2.

[0036] Comparative Example 12: The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 12 and Example 2 lies in the difference in step (2). Step (2) is modified as follows: 12.5 parts of polytetramethylene ether glycol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide are weighed and mixed uniformly, and the mixture is heated to 72° C. under a nitrogen atmosphere, and isophorone diisocyanate is added at a molar ratio of isocyanate group to hydroxyl group of 1:0.63, and 0.135 parts of dibutyltin dilaurate are added, and the mixture is heated at 300 r / min. The reaction was continued for 1.5 hours. After sampling to confirm complete reaction, the temperature was lowered to 55° C., ethylene glycol was added at a molar ratio of residual isocyanate groups to hydroxyl groups of 1:0.72, and the reaction was continued for 1.5 hours. After sampling to confirm complete reaction, a flame retardant chain extender was added at a molar ratio of residual isocyanate groups to hydroxyl groups of 1.05:1. The reaction was continued at 75° C. and 350 rpm for 2.5 hours. After sampling to confirm complete reaction, N,N-dimethylformamide was removed by vacuum distillation. 65 parts of pure water was added, and the mixture was stirred at a high speed of 1800 rpm for 45 minutes to produce a modified polyurethane emulsion. The remaining steps were the same as in Example 2.

[0037] Comparative Example 13: The preparation method of the flame-retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 13 differs from that in Example 2 in step (3). Step (3) is modified as follows: 7.5 parts of acrylic acid and 78 parts of pure water are mixed uniformly in an ice-water bath under an argon atmosphere, the pH is adjusted to 7 with a 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature is lowered to room temperature, 4.5 parts of acrylamide are added, and the mixture is stirred at 225 r / min at room temperature for 12 min. 0.11 parts of ammonium persulfate are added, and the mixture is reacted at 65°C and 225 r / min for 6.5 h. After the reaction is completed, the mixture is naturally cooled to room temperature, freeze-dried, ground, and washed with anhydrous ethanol at 250 r / min at room temperature for 5.5 h. The mixture is filtered and the mixture is repeated three times. The mixture is vacuum-dried at 55°C for 11 h to obtain a modified polyacrylic acid binder. The remaining steps are the same as those in Example 2.

[0038] Comparative Example 14: The preparation method of the flame-retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 14 differs from that in Example 2 in step (3). Step (3) is modified as follows: 7.5 parts of acrylic acid and 78 parts of pure water are mixed uniformly in an ice-water bath under an argon atmosphere, the pH is adjusted to 7 with a 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature is lowered to room temperature, 2.5 parts of acrylonitrile are added, and the mixture is stirred at 225 r / min at room temperature for 12 min. 0.11 parts of ammonium persulfate are added, and the mixture is reacted at 65°C and 225 r / min for 6.5 h. After the reaction is completed, the mixture is naturally cooled to room temperature, freeze-dried, ground, and then soaked and washed in anhydrous ethanol at 250 r / min at room temperature for 5.5 h. The mixture is filtered and the mixture is repeated three times. The mixture is vacuum-dried at 55°C for 11 h to obtain a modified polyacrylic acid binder. The remaining steps are the same as those in Example 2.

[0039] Comparative Example 15: The method for preparing a flame-retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 15 differs from that in Example 2 in step (4). Step (4) is modified as follows: 2 parts by mass of a modified polyacrylic acid binder and 80 parts by mass of pure water are mixed uniformly, stirred at 250 r / min for 18 min at room temperature, and then stirred at 900 r / min for 70 min at room temperature, and then homogenized under a high pressure of 110 MPa to obtain a conductive slurry. Subsequently, an inorganic filler is impregnated into the conductive slurry at a material-liquid ratio of 1:18 g / ml, stirred at 60 r / min for 35 min at room temperature, removed and drained, and dried in an oven at 65°C for 25 h to obtain a modified inorganic filler. The remaining steps are the same as those in Example 2.

[0040] Comparative Example 16: The method for preparing a flame-retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in Comparative Example 16 differs from that in Example 2 in that steps (3) and (4) are omitted, and step (5) is modified as follows: 20 parts by mass of modified polyurethane emulsion and 10 parts of water are mixed uniformly, stirred at 350 r / min for 2.5 min, 18 parts of calcined wollastonite powder, 20 parts of inorganic filler, and 5.5 parts of water glass are added and mixed uniformly, stirred at 700 r / min for 6 min, allowed to stand for 2.5 min, and then sprayed onto a base surface. The coating is cured at 23°C and 55% RH for 168 h to prepare a flame-retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels. The remaining steps are the same as those in Example 2.

[0041] Test Example 1: Confirmation of the optimal reaction conditions: The optimal reaction conditions were determined by changing the reaction temperature and reaction time in step (1), and the product was purified and evaluated by yield.

[0042] The results are shown in Table 1: From the comparison of the experimental data of Example 2 and Comparative Examples 1 to 8 in Table 1, it can be found that when preparing the flame retardant chain extender of the present invention, the optimal reaction conditions are 65-70° C. and reaction time of 2-2.5 h.

[0043] By comparing the data in the table, the data of Comparative Examples 1 and 2 show that a shorter reaction time cannot allow the reaction to proceed completely, resulting in a waste of raw materials and a decrease in yield.

[0044] By comparing the data in the table, the data of Comparative Examples 3 and 4 show that a longer reaction time will cause some epoxy groups to react with the hydroxyl groups in the target product, thereby forming cross-linked by-products, resulting in a decrease in yield.

[0045] By comparing the data in the table, the data of Comparative Examples 5 and 6 show that the lower reaction temperature cannot provide sufficient reaction energy, resulting in incomplete reaction and reduced yield.

[0046] By comparing the data in the table, the data of Comparative Examples 7 and 8 show that the higher reaction temperature provides too much energy, causing the epoxy group to overcome the steric hindrance and react with the hydroxyl group on the target product, resulting in the production of cross-linked by-products and a decrease in yield.

[0047] Test Example 2: Mechanical properties test: The tensile strength and bonding strength of the flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels were tested to evaluate its mechanical properties. The test was conducted with reference to the untreated tensile properties test method in GB / T 23445-2009. The tensile speed was 200 mm / min. The sample was also prepared with reference to this standard. The coating thickness was controlled at 1.5 mm ± 0.1 mm. The bonding strength was also prepared with reference to the untreated bonding strength test method in this standard. The sample was prepared and the bonding strength test was performed. Each group of samples was tested in parallel 5 times, and the average value was recorded.

[0048] The results are shown in Table 2: From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 9 to 16 in Table 2, it can be found that the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels prepared by the present invention has good tensile strength and bonding strength.

[0049] By comparing the data in the table, the data of Comparative Example 9 shows that the addition of the flame retardant chain extender can form a network structure due to the polyhydroxyl groups and more rigid structures thereon, thereby providing higher mechanical properties and effectively improving the tensile strength.

[0050] By comparing the data in the table, the data of Comparative Examples 11 to 12 show that methyl iodide and the tertiary amine groups on 3-dimethylamino-1,2-propylene glycol form a quaternary ammonium cationic structure, which has hydrophilic properties and makes the emulsion formation more uniform. When methyl iodide is not added, there are fewer hydrophilic structures in the polymer, resulting in uneven dispersion and decreased strength. Although there are a large number of tertiary amine groups due to the lack of quaternary ammonium structure, the bonding strength is also reduced due to the uneven dispersion. When neither methyl iodide nor 3-dimethylamino-1,2-propylene glycol is added, there is neither a quaternary ammonium structure nor a tertiary amine structure on the polyurethane chain segment, and both the tensile strength and the bonding strength are greatly reduced.

[0051] Test Example 3: Flame retardant performance test: The flame retardant performance of the flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels was tested with reference to MT 113-1995. The alcohol burner combustion method was used to evaluate the flame retardant performance based on the flaming combustion time, flameless combustion time, and flame extension length. The sample size was 36cm×5cm×2mm. Each group was tested in parallel 5 times, and the average value was recorded.

[0052] The results are shown in Table 3: From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 9 to 16 in Table 3, it can be found that the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels prepared by the present invention has good flame retardant properties.

[0053] By comparing the data in the table, the data of Comparative Example 9 shows that the addition of the flame retardant chain extender introduces a large amount of phosphorus and nitrogen flame retardant elements, provides effective flame retardant properties, effectively reduces the flaming combustion time, flameless combustion time and flame extension length, has excellent flame retardant properties, and forms a synergistic flame retardant effect with the silicon element in the hydroxyl-terminated fluorosilicone oil.

[0054] By comparing the data in the table, the data of Comparative Example 10 shows that the addition of hydroxyl-terminated fluorosilicone oil introduces the flame retardant element silicon, which synergizes with the flame retardant elements phosphorus and nitrogen to effectively improve the flame retardant properties of the coating.

[0055] Test Example 4: Anti-seepage and anti-static tests: The anti-seepage performance of the prepared flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels was tested with reference to the anti-seepage test method in Appendix A of GB / T 23445-2009. The thickness of the sample coating was controlled at 1.1mm±0.1mm, and the maximum water-proof pressure was recorded. The anti-static performance of the prepared flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels was tested with reference to MT 113-1995. The surface resistance was tested for evaluation. The thickness of the sample coating was controlled at 2mm±0.1mm. Each group was tested in parallel 5 times, and the average value was recorded.

[0056] The results are shown in Table 4: From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 9 to 16 in Table 4, it can be found that the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels prepared by the present invention has good anti-permeability and antistatic properties.

[0057] By comparing the data in the table, the data of Comparative Example 10 shows that the addition of hydroxyl-terminated fluorosilicone oil provides excellent hydrophobic properties and has a good water-repellent effect. At the same time, the presence of silane segments makes the polymer network more compact, which can effectively prevent the passage of water.

[0058] By comparing the data in the table, the data of Comparative Examples 11 to 12 show that the addition of iodomethane and 3-dimethylamino-1,2-propylene glycol forms a quaternary ammonium cationic structure on the polyurethane chain segment, which has ion transport capability and can form a conductive path in the polymer network, thereby forming a three-dimensional conductive network with the modified inorganic filler, thereby effectively improving the antistatic performance.

[0059] By comparing the data in the table, the data of Comparative Examples 13-14 show that the addition of acrylonitrile and acrylamide provides the modified polyacrylic acid binder with more polar groups, which can conduct electrons more effectively, thereby reducing resistance and improving antistatic performance.

[0060] By comparing the data in the table, the data of Comparative Examples 15-16 show that the modification of graphene oxide on the inorganic filler allows the graphene oxide to be uniformly dispersed in the coating with the help of the inorganic filler, and exists as a conductive node, forming a three-dimensional conductive network with the polyurethane chain segments containing quaternary ammonium cation structures, thereby effectively improving the antistatic performance.

[0061] Test Example 5: Anti-fouling performance test: The reflection coefficient decrease rate and water contact angle are tested to evaluate the anti-fouling performance of the prepared flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine tunnels. The reflection coefficient decrease rate is carried out with reference to GB / T 9780-2013, and the brushing method in the test method for stain resistance of exterior wall paint coatings is referred to. The sample coating thickness is controlled at 1.5mm±0.1mm, and the oven rapid method is used. The reflection coefficient decrease rate is tested and recorded, and the calculation formula is carried out with reference to the standard document. Each group is tested in parallel 5 times, and the average value is recorded; the water contact angle test is also tested in parallel 5 times per group, and the average value is recorded.

[0062] The results are shown in Table 5: From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 9 to 16 in Table 5, it can be found that the flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels prepared by the present invention has good antifouling performance.

[0063] By comparing the data in the table, the data of Comparative Example 10 shows that the addition of hydroxyl-terminated fluorosilicone oil introduces a large number of fluorine-containing and silicon-containing hydrophobic segments into the polyurethane chain segment, which has excellent hydrophobic properties and a tighter polymer network, reduces the penetration of pollutants in the coating, and effectively improves the stain resistance.

[0064] By comparing the data in the table, the data of Comparative Examples 11 to 12 show that the addition of iodomethane and 3-dimethylamino-1,2-propylene glycol introduces a quaternary ammonium cationic structure on the polyurethane chain segment, forming a uniformly dispersed emulsion. When these two substances are not added, the uneven dispersion of the polymer leads to uneven performance, which reduces the stain resistance and hydrophobicity of the coating.

[0065] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels, characterized in that: The flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels is prepared by mixing modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, and water glass with water, and then coating and curing the mixture. The modified polyurethane emulsion is prepared by reacting isophorone diisocyanate with polytetramethylene ether glycol and hydroxyl-terminated fluorosilicone oil, then reacting with a chain extender, and finally reacting with iodomethane and then adding water; The chain extender includes 3-dimethylamino-1,2-propylene glycol and a flame retardant chain extender; The flame retardant chain extender is prepared by reacting triglycidyl isocyanurate with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide; The modified inorganic filler is prepared by immersing the inorganic filler in a conductive paste; The conductive paste is prepared by mixing modified polyacrylic acid binder, graphene oxide and water; The modified polyacrylic acid adhesive is prepared by copolymerizing acrylic acid, acrylonitrile and acrylamide.

2. The flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 1, characterized in that: The inorganic filler includes titanium dioxide, silica powder and mica.

3. A method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels, characterized in that: The method comprises the following preparation steps: (1) Triglycidyl isocyanurate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide and tetrahydrofuran are mixed uniformly, heated and stirred to reflux for reaction, rotary evaporated and dried to obtain a flame retardant chain extender; (2) Weigh polytetramethylene glycol, hydroxyl-terminated fluorosilicone oil, and N,N-dimethylformamide, mix them, heat them under a nitrogen atmosphere, add isophorone diisocyanate and dibutyltin dilaurate, stir and react, take samples to confirm that the reaction is complete, cool them, add 3-dimethylamino-1,2-propylene glycol, react, take samples to confirm that the reaction is complete, add a flame retardant chain extender, heat and stir to react, take samples to confirm that the reaction is complete, add iodomethane, stir and react, remove N,N-dimethylformamide by vacuum distillation, add pure water, stir at high speed to obtain a modified polyurethane emulsion; (3) Under an argon atmosphere, acrylic acid and pure water are mixed in an ice-water bath, the pH is adjusted, acrylonitrile and acrylamide are added, and the mixture is stirred at room temperature. Ammonium persulfate is added, and the mixture is heated and stirred for reaction. The mixture is cooled, freeze-dried, ground, washed, filtered, and dried to obtain a modified polyacrylic acid binder. (4) Mixing a modified polyacrylic acid binder and pure water, stirring at room temperature, adding graphene oxide, stirring at room temperature, and homogenizing under high pressure to obtain a conductive slurry, impregnating an inorganic filler into the conductive slurry, stirring at room temperature, taking out, draining, and drying to obtain a modified inorganic filler; (5) The modified polyurethane emulsion and water are mixed and stirred, and calcined wollastonite powder, modified inorganic filler and water glass are added and mixed, stirred, allowed to stand, coated on the base surface, and cured to obtain a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels.

4. The method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 3, characterized in that: The flame retardant chain extender in step (1) is prepared by uniformly mixing 2 to 3 parts of triglycidyl isocyanurate, 4.97 to 7.45 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol 10-oxide, and 35 to 40 parts of tetrahydrofuran, stirring and refluxing the mixture at 65 to 70° C. and 200 to 300 r / min for 2 to 2.5 hours, removing the solvent by rotary evaporation, and vacuum drying the mixture at 50 to 60° C. for 10 to 12 hours.

5. The method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 3, characterized in that: The modified polyurethane emulsion in step (2) is weighed by weight, and 10 to 15 parts of polytetramethylene ether glycol, 5 to 6 parts of hydroxyl-terminated fluorosilicone oil, and 25 to 30 parts of N, N-dimethylformamide are mixed evenly. Under a nitrogen atmosphere, the temperature is raised to 70 to 75°C, and isophorone diisocyanate is added at a molar ratio of isocyanate group to hydroxyl group of 1: (0.58 to 0.66). 0.12 to 0.15 parts of dibutyltin dilaurate are added, and the reaction is carried out at 250 to 350 r / min for 1.5 to 2 hours. After sampling to confirm the complete reaction, the temperature is lowered to 50 to 55°C, and 3-dimethylamine is added at a molar ratio of the remaining isocyanate group to the hydroxyl group of 1: (0.7 to 0.75). The invention discloses a novel polyol preparation method comprising the steps of: adding 3-dimethylamino-1,2-propylene glycol, reacting for 1.5 to 2 hours, taking samples to confirm the complete reaction, adding a flame retardant chain extender at a molar ratio of the remaining isocyanate group to the hydroxyl group of (1 to 1.1): 1, reacting at 70 to 80°C and 300 to 400 r / min for 2 to 3 hours, taking samples to confirm the complete reaction, adding iodomethane at a molar ratio of 3-dimethylamino-1,2-propylene glycol to iodomethane of 1: (0.7 to 0.8), reacting at 25 to 30°C and 300 to 400 r / min for 1.5 to 2 hours, removing N,N-dimethylformamide by distillation under reduced pressure, adding 55 to 75 parts of pure water, and stirring at a high speed of 1500 to 2000 r / min for 40 to 50 minutes to obtain the polyol preparation method.

6. The method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 3, characterized in that: The modified polyacrylic acid binder in step (3) is prepared by uniformly mixing 7 to 8 parts of acrylic acid and 75 to 80 parts of pure water in an ice-water bath under an argon atmosphere, adjusting the pH to 7 with a 0.1 mol / L sodium hydroxide aqueous solution, and adding 2 to 3 parts of acrylonitrile and 4 to 5 parts of acrylamide after the temperature drops to room temperature. The mixture is stirred at 200 to 250 r / min for 10 to 15 minutes at room temperature, and 0.1 to 0.12 parts of ammonium persulfate are added. The mixture is reacted at 60 to 70°C and 200 to 250 r / min for 6 to 7 hours. After the reaction is completed, the mixture is naturally cooled to room temperature, freeze-dried, ground, and washed with anhydrous ethanol at 200 to 300 r / min for 5 to 6 hours at room temperature. The mixture is filtered and the mixture is repeated 3 to 4 times. The mixture is vacuum-dried at 50 to 60°C for 10 to 12 hours to obtain the modified polyacrylic acid binder.

7. The method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 3, characterized in that: The modified inorganic filler in step (4) is prepared by uniformly mixing 1.5-2.5 parts of a modified polyacrylic acid binder and 75-85 parts of pure water, and stirring at 200-300 r / min for 15-20 min at room temperature. 4-5 parts of graphene oxide are added, and stirred at 800-1000 r / min for 60-80 min at room temperature. The mixture is then homogenized at a high pressure of 100-120 MPa to obtain a conductive slurry. The inorganic filler is then impregnated into the conductive slurry at a material-liquid ratio of 1:(15-20) g / ml, and stirred at 50-70 r / min for 30-40 min at room temperature. The mixture is taken out and drained, and dried in an oven at 60-70°C for 24-26 h.

8. The method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 3, characterized in that: In the inorganic filler of step (4), the mass ratio of titanium dioxide, silica powder and mica is 1:(0.4~0.5):(0.5~0.75).

9. The method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 3, characterized in that: The flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels in step (5) is prepared by uniformly mixing 20 parts of modified polyurethane emulsion and 10 parts of water, stirring at 300-400 r / min for 2-3 minutes, adding 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 5-6 parts of water glass, stirring at 600-800 r / min for 5-7 minutes, standing for 2-3 minutes, coating on the base surface, and curing at 21-25°C and 45%RH-70%RH for 168 hours to obtain the obtained coating.

10. The method for preparing a flame retardant and antifouling organic-inorganic composite coating for underground coal mine tunnels according to claim 3, characterized in that: The calcined wollastonite powder in step (5) is obtained by calcining the wollastonite powder at 900-1100° C. in an air atmosphere for 2 h, grinding the powder, and passing it through a 325-mesh sieve.

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