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

Abstract

The application discloses a kind of coal mine underground roadway with flame-retardant antifouling organic-inorganic composite coating and preparation method thereof, it is related to composite coating technical field.The application is prepared when coal mine underground roadway with flame-retardant antifouling organic-inorganic composite coating, inorganic filler is impregnated in conductive slurry and modified inorganic filler is prepared;Modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, water glass are mixed after adding water and coated, and coal mine underground roadway with flame-retardant antifouling organic-inorganic composite coating is prepared after solidification.The flame-retardant antifouling organic-inorganic composite coating prepared by the application for coal mine underground roadway has the advantages of flame-retardant, antistatic, stain-resistant, super-hydrophobic, moisture-resistant, wear-resistant, high adhesive strength, high tensile strength.The coating has good brightness, can improve the visual conditions of underground work, and change the overall dark environment of underground roadway.

Description

Technical Field

[0001] This invention relates to the field of composite coating technology, specifically to a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways and its preparation method. Background Technology

[0002] Gas explosions are among the most dangerous accidents in coal mining enterprises. During coal mining, methane gas is continuously and slowly released from the coal seam and surrounding rock. In poorly ventilated conditions, the concentration increases. When the methane concentration is between 5% and 16%, it can explode under conditions such as blasting sparks, electrical sparks, frictional sparks, static electricity sparks, or spontaneous combustion of coal, leading to a disaster. Gas explosions have become a major obstacle to the coal industry's development towards a safer, more efficient, and technology-intensive sector. To prevent such accidents, in addition to improving ventilation and reducing methane concentration, controlling static electricity is also crucial.

[0003] Coal mine fires pose another major threat to coal mine safety. Underground coal mines are highly susceptible to fires, and these fires have a significant impact on safe production. Coal mines contain large quantities of combustible materials, such as coal, gas, coal dust, pit props, oil, explosives, and various mechanical and electrical equipment, making them extremely prone to fire. Once a fire occurs, it can range from affecting safe production to destroying coal resources and equipment, causing casualties, and even triggering gas and coal dust explosions.

[0004] Water seepage is a common phenomenon in coal mines, impacting production and management. During mining and tunneling, water continuously seeps from the coal seam and surrounding rock into the mining face and roadways, characterized by its wide reach, long duration, and slow seepage rate. This seepage keeps the mine damp, affecting environmental conditions and production efficiency; it necessitates continuous drainage, increasing production costs; and mine water has a corrosive effect, causing various metal equipment, rails, and supports to rust and shorten their service life.

[0005] In recent years, coating materials have been used in underground coal mine roadways to help solve the aforementioned problems. These coatings are sprayed onto the surfaces of roadways, goafs, or coal and rock masses, requiring properties such as waterproofing, moisture resistance, gloss, fire resistance, and antistatic properties, as well as flame retardancy and prevention of water seepage and gas leakage from the coal face. However, currently used coatings suffer from insufficient impermeability, flame retardancy, and antistatic properties. They also exhibit poor gloss, failing to address the overall darkness of underground roadways, and exhibit poor adhesion to cement mortar, concrete, and masonry surfaces, leading to easy detachment. Summary of the Invention

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

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] A flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways is prepared by mixing modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, and water glass with water, coating the mixture, and then curing it.

[0009] The modified polyurethane emulsion is prepared by reacting isophorone diisocyanate with polytetrahydrofuran ether diol and hydroxyl-terminated fluorosilicone oil, then reacting with a chain extender, and finally reacting with iodomethane and adding water.

[0010] The chain extender includes 3-dimethylamino-1,2-propanediol and a flame-retardant chain extender;

[0011] The flame retardant chain extender is prepared by reacting triglycidyl isocyanurate with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide.

[0012] The modified inorganic filler is prepared by impregnating the inorganic filler in a conductive slurry;

[0013] The conductive paste is prepared by mixing modified polyacrylic acid binder, graphene oxide, and water.

[0014] The modified polyacrylic acid adhesive is prepared by copolymerizing acrylic acid, acrylonitrile, and acrylamide.

[0015] As an optimization, the inorganic filler includes titanium dioxide, silicon powder, and mica.

[0016] A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways includes the following preparation steps:

[0017] (1) By mass fraction, 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 are mixed evenly and stirred under reflux at 65-70°C and 200-300 r / min for 2-2.5 h. The solvent is removed by rotary evaporation and the mixture is dried under vacuum at 50-60°C for 10-12 h to obtain a flame retardant chain extender.

[0018] (2) Weigh 10-15 parts of polytetrahydrofuran ether diol, 5-6 parts of hydroxyl-terminated fluorosilicone oil, and 25-30 parts of N,N-dimethylformamide by mass and mix them evenly. Under a nitrogen atmosphere, heat to 70-75℃, add isophorone diisocyanate at a molar ratio of isocyanate to hydroxyl groups of 1:(0.58-0.66), add 0.12-0.15 parts of dibutyltin dilaurate, and react at 250-350 r / min for 1.5-2 h. After confirming complete reaction by sampling, cool to 50-55℃, and add 3-dimethylamino-1,2-propanediol at a molar ratio of the remaining isocyanate to hydroxyl groups of 1:(0.7-0.75). After reacting for 1.5-2 hours and confirming complete reaction by sampling, a flame retardant chain extender is added at a molar ratio of (1-1.1):1 of the remaining isocyanate groups to hydroxyl groups. The reaction is carried out at 70-80℃ and 300-400 r / min for 2-3 hours. After confirming complete reaction by sampling, iodomethane is added at a molar ratio of 3-dimethylamino-1,2-propanediol to iodomethane of 1:(0.7-0.8). The reaction is carried out at 25-30℃ and 300-400 r / min for 1.5-2 hours. N,N-dimethylformamide is removed by vacuum distillation. 55-75 parts of pure water are added, and the mixture is stirred at 1500-2000 r / min for 40-50 minutes to obtain a modified polyurethane emulsion.

[0019] (3) By mass, under an argon atmosphere, in an ice-water bath, mix 7-8 parts of acrylic acid and 75-80 parts of pure water evenly, adjust the pH to 7 with 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature drops to room temperature, add 2-3 parts of acrylonitrile and 4-5 parts of acrylamide, stir at 200-250 r / min for 10-15 min at room temperature, add 0.1-0.12 parts of ammonium persulfate, react at 60-70℃ and 200-250 r / min for 6-7 h, cool naturally to room temperature after the reaction, freeze dry, grind, soak and wash in anhydrous ethanol at 200-300 r / min for 5-6 h at room temperature, filter, repeat 3-4 times, and vacuum dry at 50-60℃ for 10-12 h to obtain modified polyacrylic acid adhesive;

[0020] (4) Mix 1.5-2.5 parts of modified polyacrylic acid binder and 75-85 parts of pure water evenly by mass, stir at 200-300 r / min for 15-20 min at room temperature, add 4-5 parts of graphene oxide, stir at 800-1000 r / min for 60-80 min at room temperature, and then homogenize under high pressure of 100-120 MPa to obtain conductive slurry. Then, impregnate inorganic filler into conductive slurry at a material-liquid ratio of 1:(15-20) g / ml, stir at 50-70 r / min for 30-40 min at room temperature, take out and drain, and dry in an oven at 60-70℃ for 24-26 h to obtain modified inorganic filler;

[0021] (5) By mass, mix 20 parts of modified polyurethane emulsion and 10 parts of water evenly, stir at 300~400r / min for 2~3min, add 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 5~6 parts of water glass evenly, stir at 600~800r / min for 5~7min, let stand for 2~3min, apply to the base surface, and cure at 21~25℃ and 45%RH~70%RH for 168h to obtain a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways.

[0022] As an optimization, the reaction process of the flame retardant chain extender in step (1) is as follows:

[0023] .

[0024] As an optimization, in the inorganic filler described in step (4), the mass ratio of titanium dioxide, silicon powder, and mica is 1:(0.4~0.5):(0.5~0.75).

[0025] As an optimization, the calcined wollastonite powder in step (5) is obtained by calcining wollastonite powder in an air atmosphere at 900~1100℃ for 2 hours, grinding it, and then passing it through a 325-mesh sieve.

[0026] As an optimization, the water glass in step (5) is Na2O·nSiO2 with a modulus of 1.2 and an alkali equivalent of 10%.

[0027] As an optimization, the coating in step (5) can be applied by spraying, scraping, brushing or rolling.

[0028] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0029] In preparing a flame-retardant and stain-resistant organic-inorganic composite coating for underground coal mine roadways, this invention first reacts triglycidyl isocyanurate with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide to obtain a flame-retardant chain extender; then, isophorone diisocyanate reacts with polytetrahydrofuran ether glycol and hydroxyl-terminated fluorosilicone oil, followed by reactions with 3-dimethylamino-1,2-propanediol and the flame-retardant chain extender, and finally reacts with iodomethane before adding... A modified polyurethane emulsion was prepared by water preparation; a modified polyacrylic acid binder was prepared by copolymerizing acrylic acid, acrylonitrile, and acrylamide; a conductive slurry was prepared by mixing the modified polyacrylic acid binder and graphene oxide with water, and then a modified inorganic filler was prepared by impregnating the conductive slurry; a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways was prepared by mixing the modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, and water glass with water, applying the mixture by scraping, and curing.

[0030] First, the epoxy groups on triglycidyl isocyanurate react with the hydroxyl groups on 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide to obtain a flame-retardant chain extender containing a large amount 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 chain extender for polyurethane. The introduction of a large number of rigid rings can improve the mechanical properties of polyurethane segments and enhance the support 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 performance. Isophorone diisocyanate first reacts with polytetrahydrofuran ether glycol and hydroxyl-terminated fluorosilicone oil, then reacts with 3-dimethylamino-1,2-propanediol 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 migrate to the outer surface due to differences in surface energy during the curing process, thus obtaining a superhydrophobic product. The outer surface effectively improves antifouling and impermeability. It also contains a large amount of flame-retardant silicon, which can form a synergistic flame-retardant effect with the flame-retardant elements phosphorus and nitrogen in the flame-retardant chain extender, thereby significantly improving flame-retardant performance. 3-Dimethylamino-1,2-propanediol in the polyurethane chain is a chain extender with tertiary amine groups. Part of it reacts with iodomethane to form quaternary ammonium cations. Quaternary ammonium cations are hydrophilic groups, allowing the synthesized polyurethane to form an emulsion in water. At the same time, the quaternary ammonium cations distributed throughout the polyurethane chain can also exist as conductive pathways, thereby improving antistatic properties. The other part of the tertiary amine groups remain unchanged. They can form a strong bond with the calcined wollastonite powder and fillers in the substrate and coating through hydrogen bonding, electrostatic interaction, etc. This improves the mechanical properties of the coating and the bonding strength, allowing it to adhere firmly to the tunnel wall surface and not easily fall off, thus extending its service life.

[0031] Secondly, a modified polyacrylic acid adhesive is prepared by copolymerizing acrylic acid, acrylonitrile, and acrylamide. Acrylic acid and acrylamide act as adhesive providers, providing adhesion through electrostatic, hydrogen bonding, and complexation interactions. The polar groups in acrylonitrile and acrylamide, such as nitrile and amide groups, provide conductivity and can further improve antistatic properties. After the modified polyacrylic acid adhesive is compounded with graphene oxide to form a conductive slurry, it is coated onto the surface of inorganic fillers by impregnation, thereby forming a conductive layer on the surface of the inorganic fillers. This method effectively avoids the problem of difficult dispersion of graphene oxide in the coating matrix and avoids the problem of performance degradation caused by the agglomeration of graphene oxide in the coating matrix. Through the conductive layer on the surface of the inorganic fillers, they exist as nodes in the conductive network.

[0032] Finally, the modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, and water glass are mixed with water and then coated to form a coating. The modified polyurethane emulsion provides good adhesion, support, hydrophobic and antifouling properties, flame retardancy, and antistatic properties. Simultaneously, the modified inorganic filler acts as conductive nodes, and the polymer network formed by the modified polyurethane emulsion acts as conductive pathways, thus forming a three-dimensional conductive network in the coating, greatly improving the antistatic properties. The polyurethane segments with silane chains have a more compact structure, and with the water-repellent properties of silane and fluorine segments, it also has good waterproof and impermeable properties. The calcined wollastonite powder can undergo a hydration reaction and gel under the action of water glass, thus forming a denser structure. High-refractive-index titanium dioxide is also added to the filler; its high refractive index can effectively reflect light, thereby improving brightness and alleviating the dark environment of underground roadways. This makes it effective for use in coal mine underground roadway environments. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] The following information is provided for the raw materials used in all the following examples and comparative examples:

[0035] Polytetrahydrofuran ether diol: model PTMEG T-1000, weight average molecular weight 1000, purchased from Hangzhou Weitong Nanomaterials Co., Ltd.

[0036] Hydroxyl-terminated fluorosilicone oil: model NFS7200, weight average molecular weight 1000, purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.

[0037] Graphene oxide: Model number XFSG01, purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.

[0038] Wollastonite powder: Ultrafine wollastonite powder, particle size 1250 mesh, purchased from Jiangxi Chenxin New Materials Co., Ltd.;

[0039] Inorganic filler: The mass ratio of titanium dioxide, silica powder, and mica is 1:0.45:0.6;

[0040] Titanium dioxide: Model R-982, purchased from Longbai Sichuan Titanium Industry Co., Ltd.;

[0041] Silicon powder: Product number Si0343251000, purchased from Beijing Juguang Wintech Technology Co., Ltd.;

[0042] Mica: Mica powder, 50 mesh, purchased from Lingshou County Shunyong Mineral Products Co., Ltd.

[0043] 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 it, and passing it through a 325-mesh sieve.

[0044] Example 1:

[0045] A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways, comprising the following preparation steps:

[0046] (1) By mass fraction, 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 and stirred under reflux at 65°C and 200 r / min for 2.5 h. The solvent was removed by rotary evaporation and the mixture was dried under vacuum at 50°C for 12 h to obtain the flame retardant chain extender.

[0047] (2) Weigh 10 parts of polytetrahydrofuran ether diol, 5 parts of hydroxyl-terminated fluorosilicone oil, and 25 parts of N,N-dimethylformamide by mass and mix them evenly. Under a nitrogen atmosphere, heat to 70°C, add isophorone diisocyanate at a molar ratio of isocyanate to hydroxyl groups of 1:0.58, add 0.12 parts of dibutyltin dilaurate, and react at 250 r / min for 2 h. After confirming complete reaction by sampling, cool to 50°C, and add 3-dimethylamino-1,2-propanediol at a molar ratio of the remaining isocyanate to hydroxyl groups of 1:0.7. The alcohol was reacted for 1.5 h. After sampling to confirm complete reaction, a flame retardant chain extender was added at a molar ratio of 1:1 between the remaining isocyanate groups and hydroxyl groups. The reaction was carried out at 70 °C and 300 r / min for 3 h. After sampling to confirm complete reaction, iodomethane was added at a molar ratio of 1:0.7 between 3-dimethylamino-1,2-propanediol and iodomethane. The reaction was carried out at 25 °C and 300 r / min for 2 h. N,N-dimethylformamide was removed by vacuum distillation. 55 parts of pure water were added, and the mixture was stirred at 1500 r / min for 50 min to obtain a modified polyurethane emulsion.

[0048] (3) By mass, under an argon atmosphere, in an ice-water bath, 7 parts of acrylic acid and 75 parts of pure water were mixed evenly, the pH was adjusted to 7 with 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature was lowered 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 were added, and the mixture was reacted at 60℃ 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 then filtered, repeated 3 times, and vacuum dried at 50℃ for 12 h to obtain the modified polyacrylic acid adhesive.

[0049] (4) By mass, 1.5 parts of modified polyacrylic acid adhesive and 75 parts of pure water are mixed evenly, stirred at 200 r / min for 20 min at room temperature, 4 parts of graphene oxide are added, stirred at 800 r / min for 80 min at room temperature, and then homogenized under high pressure of 100 MPa to obtain conductive slurry. Then, inorganic filler is impregnated into conductive slurry at a material-liquid ratio of 1:15 g / ml, stirred at 50 r / min for 40 min at room temperature, drained, and dried in an oven at 60℃ for 26 h to obtain modified inorganic filler;

[0050] (5) By mass, 20 parts of modified polyurethane emulsion and 10 parts of water are mixed evenly, stirred at 300 r / min for 3 min, 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 5 parts of water glass are added and mixed evenly, stirred at 600 r / min for 7 min, left to stand for 3 min, sprayed on the base surface, and cured at 21℃ and 45%RH for 168 h to obtain a flame-retardant and anti-fouling organic-inorganic composite coating for coal mine underground roadways.

[0051] Example 2:

[0052] A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways, comprising the following preparation steps:

[0053] (1) By mass fraction, 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 and stirred under reflux at 65°C and 250 r / min for 2 h. The solvent was removed by rotary evaporation and the mixture was dried under vacuum at 55°C for 11 h to obtain the flame retardant chain extender.

[0054] (2) Weigh 12.5 parts of polytetrahydrofuran ether diol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide by mass and mix them evenly. Under a nitrogen atmosphere, heat to 72°C, add isophorone diisocyanate at a molar ratio of isocyanate to hydroxyl groups of 1:0.63, add 0.135 parts of dibutyltin dilaurate, and react at 300 r / min for 1.5 h. After taking a sample to confirm complete reaction, cool down to 55°C, and add 3-dimethylamino-1,2-propanediol at a molar ratio of the remaining isocyanate to hydroxyl groups of 1:0.72. The alcohol was reacted for 1.5 h. After sampling to confirm complete reaction, a flame retardant chain extender was added at a molar ratio of 1.05:1 for the remaining isocyanate groups to hydroxyl groups. The reaction was carried out at 75 °C and 350 r / min for 2.5 h. After sampling to confirm complete reaction, iodomethane was added at a molar ratio of 1:0.75 for 3-dimethylamino-1,2-propanediol. The reaction was carried out at 28 °C and 350 r / min for 1.5 h. N,N-dimethylformamide was removed by vacuum distillation. 65 parts of pure water were added, and the mixture was stirred at 1800 r / min for 45 min to obtain a modified polyurethane emulsion.

[0055] (3) By mass, under an argon atmosphere, in an ice-water bath, 7.5 parts of acrylic acid and 78 parts of pure water were mixed evenly, the pH was adjusted to 7 with 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature was lowered to room temperature, 2.5 parts of acrylonitrile and 4.5 parts of acrylamide were added. The mixture was stirred at 225 r / min for 12 min at room temperature, and 0.11 parts of ammonium persulfate were added. The mixture was reacted at 65℃ 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 for 5.5 h at room temperature. The mixture was then filtered and repeated 3 times. The mixture was then vacuum dried at 55℃ for 11 h to obtain the modified polyacrylic acid adhesive.

[0056] (4) By mass, 2 parts of modified polyacrylic acid adhesive and 80 parts of pure water are mixed evenly, stirred at 250 r / min for 18 min at room temperature, 4.5 parts of graphene oxide are added, stirred at 900 r / min for 70 min at room temperature, and then homogenized under high pressure of 110 MPa to obtain conductive slurry. Then, inorganic filler is impregnated into conductive slurry at a material-liquid ratio of 1:18 g / ml, stirred at 60 r / min for 35 min at room temperature, drained, and dried in an oven at 65℃ for 25 h to obtain modified inorganic filler;

[0057] (5) By mass, 20 parts of modified polyurethane emulsion and 10 parts of water are 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 are added and mixed evenly, stirred at 700 r / min for 6 min, left to stand for 2.5 min, sprayed on the base surface, and cured at 23℃ and 55%RH for 168 h to obtain a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways.

[0058] Example 3:

[0059] A method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways, comprising the following preparation steps:

[0060] (1) By mass fraction, 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 and stirred under reflux at 70°C and 300 r / min for 2 h. The solvent was removed by rotary evaporation and the mixture was dried under vacuum at 60°C for 10 h to obtain the flame retardant chain extender.

[0061] (2) Weigh 15 parts of polytetrahydrofuran ether diol, 6 parts of hydroxyl-terminated fluorosilicone oil, and 30 parts of N,N-dimethylformamide by mass and mix them evenly. Under a nitrogen atmosphere, heat to 75°C, add isophorone diisocyanate at a molar ratio of isocyanate to hydroxyl groups of 1:0.66, add 0.15 parts of dibutyltin dilaurate, and react at 350 r / min for 1.5 h. After confirming complete reaction by taking a sample, cool down to 55°C, and add 3-dimethylamino-1,2-propanediol at a molar ratio of the remaining isocyanate to hydroxyl groups of 1:0.75. After reacting with alcohol for 2 hours and confirming complete reaction by sampling, flame retardant chain extender was added at a molar ratio of 1.1:1 for the remaining isocyanate groups to hydroxyl groups. The reaction was carried out at 80°C and 400 r / min for 2 hours. After confirming complete reaction by sampling, iodomethane was added at a molar ratio of 1:0.8 for 3-dimethylamino-1,2-propanediol. The reaction was carried out at 30°C and 400 r / min for 1.5 hours. N,N-dimethylformamide was removed by vacuum distillation. 75 parts of pure water were added, and the mixture was stirred at 2000 r / min for 40 minutes to obtain a modified polyurethane emulsion.

[0062] (3) By mass, under an argon atmosphere, in an ice-water bath, 8 parts of acrylic acid and 80 parts of pure water were mixed evenly, the pH was adjusted to 7 with 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature was lowered to room temperature, 3 parts of acrylonitrile and 5 parts of acrylamide were added. The mixture was stirred at 250 r / min for 10 min at room temperature, and 0.12 parts of ammonium persulfate were added. The mixture was reacted at 70℃ 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 then filtered and repeated 4 times. The mixture was then vacuum dried at 60℃ for 10 h to obtain the modified polyacrylic acid adhesive.

[0063] (4) By mass, 2.5 parts of modified polyacrylic acid binder and 85 parts of pure water are mixed evenly, stirred at 300 r / min for 15 min at room temperature, 5 parts of graphene oxide are added, stirred at 1000 r / min for 60 min at room temperature, and then homogenized under high pressure of 120 MPa to obtain conductive slurry. Then, inorganic filler is impregnated into conductive slurry at a material-liquid ratio of 1:20 g / ml, stirred at 70 r / min for 30 min at room temperature, drained, and dried in an oven at 70℃ for 24 h to obtain modified inorganic filler;

[0064] (5) By mass, 20 parts of modified polyurethane emulsion and 10 parts of water are mixed evenly, stirred at 400 r / min for 2 min, 18 parts of calcined wollastonite powder, 20 parts of modified inorganic filler and 6 parts of water glass are added and mixed evenly, stirred at 800 r / min for 5 min, left to stand for 2 min, sprayed on the base surface, and cured at 25℃ and 70%RH for 168 h to obtain a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways.

[0065] Comparative Example 1:

[0066] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 1 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 65°C and 250 r / min for 1 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0067] Comparative Example 2:

[0068] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 2 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 65°C and 250 r / min for 1.5 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0069] Comparative Example 3:

[0070] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 3 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 65°C and 250 r / min for 3 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0071] Comparative Example 4:

[0072] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 4 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 65°C and 250 r / min for 3.5 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0073] Comparative Example 5:

[0074] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 5 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 50°C and 250 r / min for 2 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0075] Comparative Example 6:

[0076] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 6 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 55°C and 250 r / min for 2 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0077] Comparative Example 7:

[0078] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 7 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 80°C and 250 r / min for 2 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0079] Comparative Example 8:

[0080] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 8 and Example 2 lies in the different step (1). Step (1) is modified as follows: 2.5 parts by mass of triglycidyl isocyanurate, 6.21 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide, and 38 parts by mass of tetrahydrofuran are mixed evenly and stirred under reflux at 85°C and 250 r / min for 2 h. The solvent is removed by rotary evaporation, and the mixture is vacuum dried at 55°C for 11 h to obtain the flame-retardant chain extender. The remaining steps are the same as in Example 2.

[0081] Comparative Example 9:

[0082] The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 9 differs from that in Example 2 in that step (1) is omitted, and step (2) is modified as follows: Weigh 12.5 parts of polytetrahydrofuran ether diol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide by mass, mix them evenly, heat to 72°C under a nitrogen atmosphere, add isophorone diisocyanate at a molar ratio of isocyanate to hydroxyl groups of 1:0.63, add 0.135 parts of dibutyltin dilaurate, react at 300 r / min for 1.5 h, take a sample to confirm complete reaction, cool down to 55°C, and add the remaining isocyanate groups and hydroxyl groups... 3-Dimethylamino-1,2-propanediol was added at a molar ratio of hydroxyl groups of 1:0.72 and reacted for 1.5 h. After confirming complete reaction by sampling, ethylene glycol was added at a molar ratio of remaining isocyanate groups to hydroxyl groups of 1.05:1. The reaction was carried out at 75°C and 350 r / min for 2.5 h. After confirming complete reaction by sampling, iodomethane was added at a molar ratio of 3-dimethylamino-1,2-propanediol to iodomethane of 1:0.75 and reacted at 28°C and 350 r / min for 1.5 h. N,N-dimethylformamide was removed by vacuum distillation, and 65 parts of pure water were added. The mixture was stirred at 1800 r / min for 45 min to obtain the modified polyurethane emulsion. The remaining steps were the same as in Example 2.

[0083] Comparative Example 10:

[0084] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 10 and Example 2 lies in the different step (2). Step (2) is modified as follows: Weigh 18 parts of polytetrahydrofuran ether diol and 28 parts of N,N-dimethylformamide by mass, mix them evenly, heat to 72°C under a nitrogen atmosphere, add isophorone diisocyanate according to the molar ratio of isocyanate groups to hydroxyl groups of 1:0.63, add 0.135 parts of dibutyltin dilaurate, react at 300 r / min for 1.5 h, take a sample to confirm complete reaction, cool down to 55°C, and add the remaining isocyanate groups to hydroxyl groups according to the molar ratio of the remaining isocyanate groups to hydroxyl groups of 1:0.63. 3-Dimethylamino-1,2-propanediol was added at a ratio of 1:0.72, and the reaction was carried out for 1.5 hours. After sampling to confirm complete reaction, a flame retardant chain extender was added at a molar ratio of 1.05:1 for the remaining isocyanate groups to hydroxyl groups. The reaction was carried out at 75°C and 350 rpm for 2.5 hours. After sampling to confirm complete reaction, iodomethane was added at a molar ratio of 1:0.75 for 3-dimethylamino-1,2-propanediol. The reaction was carried out at 28°C and 350 rpm for 1.5 hours. N,N-dimethylformamide was removed by vacuum distillation, and 65 parts of pure water were added. The mixture was stirred at 1800 rpm for 45 minutes to obtain the modified polyurethane emulsion. The remaining steps were the same as in Example 2.

[0085] Comparative Example 11:

[0086] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 11 and Example 2 lies in the different step (2). Step (2) is modified as follows: Weigh 12.5 parts of polytetrahydrofuran ether diol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide by mass, mix them evenly, heat to 72°C under a nitrogen atmosphere, add isophorone diisocyanate at a molar ratio of isocyanate group to hydroxyl group of 1:0.63, add 0.135 parts of dibutyltin dilaurate, and react at 300 r / min for 1.5 minutes. After confirming complete reaction by sampling, the temperature was lowered to 55°C, and 3-dimethylamino-1,2-propanediol was added at a molar ratio of 1:0.72 for the remaining isocyanate groups to hydroxyl groups. The reaction was carried out for 1.5 hours, and after confirming complete reaction by sampling, a flame retardant chain extender was added at a molar ratio of 1.05:1 for the remaining isocyanate groups to hydroxyl groups. The reaction was carried out at 75°C and 350 r / min for 2.5 hours. After confirming complete reaction by sampling, N,N-dimethylformamide was removed by vacuum distillation, and 65 parts of pure water were added. The mixture was stirred at 1800 r / min for 45 minutes to obtain the modified polyurethane emulsion. The remaining steps were the same as in Example 2.

[0087] Comparative Example 12:

[0088] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 12 and Example 2 lies in the different step (2). Step (2) is modified as follows: Weigh 12.5 parts of polytetrahydrofuran ether diol, 5.5 parts of hydroxyl-terminated fluorosilicone oil, and 28 parts of N,N-dimethylformamide by mass, mix them evenly, heat to 72°C under a nitrogen atmosphere, add isophorone diisocyanate at a molar ratio of isocyanate group to hydroxyl group of 1:0.63, add 0.135 parts of dibutyltin dilaurate, and spray at 300 r / min. After reacting for 1.5 hours and confirming complete reaction by sampling, the temperature was lowered to 55°C. Ethylene glycol was added at a molar ratio of 1:0.72 for the remaining isocyanate groups to hydroxyl groups, and the reaction was continued for 1.5 hours. After confirming complete reaction by sampling, a flame retardant chain extender was added at a molar ratio of 1.05:1 for the remaining isocyanate groups to hydroxyl groups. The reaction was carried out at 75°C and 350 rpm for 2.5 hours. After confirming complete reaction by sampling, N,N-dimethylformamide was removed by vacuum distillation. 65 parts of pure water were added, and the mixture was stirred at 1800 rpm for 45 minutes to obtain the modified polyurethane emulsion. The remaining steps were the same as in Example 2.

[0089] Comparative Example 13:

[0090] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 13 and Example 2 lies in step (3). Step (3) is modified as follows: By mass, under an argon atmosphere and in an ice-water bath, 7.5 parts of acrylic acid and 78 parts of pure water are mixed evenly, the pH is adjusted to 7 with 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature is lowered to room temperature, 4.5 parts of acrylamide are added. The mixture is stirred at 225 r / min for 12 min at room temperature, and 0.11 parts of ammonium persulfate are added. 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 for 5.5 h at room temperature. The mixture is then filtered, repeated 3 times, and vacuum dried at 55°C for 11 h to obtain the modified polyacrylic acid adhesive. The remaining steps are the same as in Example 2.

[0091] Comparative Example 14:

[0092] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 14 and Example 2 lies in step (3). Step (3) is modified as follows: By mass, under an argon atmosphere and in an ice-water bath, 7.5 parts of acrylic acid and 78 parts of pure water are mixed evenly, the pH is adjusted to 7 with 0.1 mol / L sodium hydroxide aqueous solution, and after the temperature is lowered to room temperature, 2.5 parts of acrylonitrile are added. The mixture is stirred at 225 r / min for 12 min at room temperature, and 0.11 parts of ammonium persulfate are added. 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 for 5.5 h at room temperature. The mixture is then filtered, repeated 3 times, and vacuum dried at 55°C for 11 h to obtain the modified polyacrylic acid adhesive. The remaining steps are the same as in Example 2.

[0093] Comparative Example 15:

[0094] The difference between the preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways in Comparative Example 15 and Example 2 lies in step (4). Step (4) is modified as follows: 2 parts by mass of modified polyacrylic acid binder and 80 parts by mass of pure water are mixed evenly, stirred at 250 r / min for 18 min at room temperature, then stirred at 900 r / min for 70 min at room temperature, and then homogenized under high pressure of 110 MPa to obtain a conductive slurry. Inorganic filler is then impregnated into the conductive slurry at a material-to-liquid ratio of 1:18 g / ml, stirred at 60 r / min for 35 min at room temperature, drained, and dried in an oven at 65℃ for 25 h to obtain the modified inorganic filler. The remaining steps are the same as in Example 2.

[0095] Comparative Example 16:

[0096] The preparation method of the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways 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 by mass of water are mixed evenly, stirred at 350 r / min for 2.5 min, 18 parts by mass of calcined wollastonite powder, 20 parts by mass of inorganic filler, and 5.5 parts by mass of water glass are added and mixed evenly, stirred at 700 r / min for 6 min, allowed to stand for 2.5 min, sprayed onto the substrate, and cured at 23°C and 55% RH for 168 h to obtain the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways. The remaining steps are the same as in Example 2.

[0097] Test Example 1:

[0098] Confirmation of 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.

[0099] The results are shown in Table 1:

[0100]

[0101] A comparison of the experimental data from Example 2 and Comparative Examples 1-8 in Table 1 reveals that the optimal reaction conditions for preparing the flame retardant chain extender in this invention are 65-70°C for 2-2.5 hours.

[0102] By comparing the data in the table, it can be seen from the data in Examples 1 and 2 that a shorter reaction time cannot allow the reaction to proceed completely, resulting in waste of raw materials and reduced yield.

[0103] The data in the table shows that the longer reaction time can cause some epoxy groups to react with the hydroxyl groups in the target product, forming cross-linked byproducts and resulting in a decrease in yield.

[0104] By comparing the data in the table, the data in Comparative Examples 5 and 6 show that the lower reaction temperature cannot provide enough reaction energy, resulting in incomplete reaction and reduced yield.

[0105] The data comparison in the table shows that the higher reaction temperature provides excessive energy, causing the epoxy groups to overcome steric hindrance and react with the hydroxyl groups on the target product, resulting in the formation of cross-linking byproducts and a decrease in yield.

[0106] Test Example 2:

[0107] Mechanical property testing: The tensile strength and bond strength of the prepared flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways were tested to evaluate its mechanical properties. The tensile properties test method without treatment in GB / T 23445-2009 was followed, with a tensile speed of 200 mm / min. The sample preparation was also carried out in accordance with this standard, and the coating thickness was controlled at 1.5 mm ± 0.1 mm. The bond strength test was also carried out in accordance with the bond strength test method without treatment in this standard. Each group of samples was tested in parallel 5 times, and the average value was recorded.

[0108] The results are shown in Table 2:

[0109]

[0110] A comparison of the experimental data from Examples 1-3 and Comparative Examples 9-16 in Table 2 reveals that the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways prepared by this invention has good tensile strength and adhesive strength.

[0111] By comparing the data in the table, the data in Comparative Example 9 shows that the addition of flame retardant chain extenders provides higher mechanical properties and effectively improves tensile strength because the polyhydroxyl groups can form a network structure and have more rigid structures on it.

[0112] Comparing the data in the table, the data from Comparative Examples 11-12 show that iodomethane forms a quaternary ammonium cationic structure with the tertiary amine groups on 3-dimethylamino-1,2-propanediol, which has hydrophilic properties, resulting in a more uniform emulsion formation. When iodomethane is not added, there are fewer hydrophilic structures in the polymer, leading to uneven dispersion and a decrease in strength. Although there are a large number of tertiary amine groups due to the lack of quaternary ammonium structure, the uneven dispersion also leads to a decrease in bond strength. When neither iodomethane nor 3-dimethylamino-1,2-propanediol is added, there are neither quaternary ammonium nor tertiary amine structures on the polyurethane segments, resulting in a significant decrease in both tensile strength and bond strength.

[0113] Test Example 3:

[0114] Flame retardant performance test: The flame retardant performance of the prepared flame retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways was tested according to MT 113-1995. The test was conducted using the alcohol torch burning method. The flame retardant performance was evaluated by the flame burning time, flameless burning time and flame spread length. The sample size was 36cm×5cm×2mm. Each group was tested in parallel 5 times and the average value was recorded.

[0115] The results are shown in Table 3:

[0116]

[0117] A comparison of the experimental data from Examples 1-3 and Comparative Examples 9-16 in Table 3 reveals that the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways prepared by this invention has excellent flame-retardant properties.

[0118] By comparing the data in the table, the data in Comparative Example 9 shows that the addition of flame retardant chain extender introduces a large number of phosphorus and nitrogen flame retardant elements, providing effective flame retardant performance, effectively reducing the flaming combustion time, flameless combustion time and flame spread length, exhibiting excellent flame retardant performance, and forming a synergistic flame retardant effect with the silicon element in hydroxyl-terminated fluorosilicone oil.

[0119] The data comparison in the table shows that the addition of hydroxyl-terminated fluorosilicone oil introduces the flame-retardant element silicon, which, in conjunction with the flame-retardant elements phosphorus and nitrogen, effectively improves the flame-retardant performance of the coating.

[0120] Test Example 4:

[0121] Permeability and Antistatic Tests: The permeability performance of the prepared flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways was tested according to the permeability test method in Appendix A of GB / T 23445-2009. The coating thickness of the sample was controlled at 1.1 mm ± 0.1 mm, and the maximum impermeable pressure was recorded. The antistatic performance of the prepared flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways was tested according to MT 113-1995. The surface resistance was tested for evaluation. The coating thickness of the sample was controlled at 2 mm ± 0.1 mm. Each group was tested in parallel for 5 times, and the average value was recorded.

[0122] The results are shown in Table 4:

[0123]

[0124] A comparison of the experimental data from Examples 1-3 and Comparative Examples 9-16 in Table 4 reveals that the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways prepared by this invention has excellent impermeability and antistatic properties.

[0125] By comparing the data in the table, the data in 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 water from passing through.

[0126] By comparing the data in the table, the data from Comparative Examples 11-12 show that the addition of iodomethane and 3-dimethylamino-1,2-propanediol forms a quaternary ammonium cation structure on the polyurethane chain segment, which has ion transport capabilities and can form conductive pathways in the polymer network. This, in turn, forms a three-dimensional conductive network with the modified inorganic filler, thereby effectively improving the antistatic properties.

[0127] By comparing the data in the table, the data in Comparative Examples 13-14 show that the addition of acrylonitrile and acrylamide gives the modified polyacrylic acid adhesive more polar groups, which can more effectively conduct electrons, thereby reducing resistance and improving antistatic properties.

[0128] By comparing the data in the table, the data in Comparative Examples 15-16 show that the modification of graphene oxide on inorganic fillers allows graphene oxide to be uniformly dispersed in the coating with the help of inorganic fillers, and exists as conductive nodes. It forms a three-dimensional conductive network with polyurethane segments containing quaternary ammonium cation structures, thereby effectively improving the antistatic properties.

[0129] Test Example 5:

[0130] Stain resistance test: The stain resistance of the prepared flame-retardant and stain-resistant organic-inorganic composite coating for underground coal mine roadways was evaluated by testing the reflection coefficient reduction rate and water contact angle. The reflection coefficient reduction rate was tested according to GB / T 9780-2013, specifically the brushing method in the test method for stain resistance of exterior wall coatings. The coating thickness was controlled at 1.5mm ± 0.1mm, and the oven drying method was used. The reflection coefficient reduction rate was recorded, and the calculation formula was based on the standard document. Each group was tested in parallel for 5 times, and the average value was recorded. The water contact angle test was also conducted in parallel for 5 times, and the average value was recorded.

[0131] The results are shown in Table 5:

[0132]

[0133] A comparison of the experimental data from Examples 1-3 and Comparative Examples 9-16 in Table 5 reveals that the flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways prepared by this invention has excellent anti-fouling properties.

[0134] The data comparison in the table shows that the addition of hydroxyl-terminated fluorosilicone oil introduces a large number of fluorinated and silicon-containing hydrophobic segments into the polyurethane chain, resulting in excellent hydrophobic properties and a more compact polymer network. This reduces the penetration of contaminants into the coating and effectively improves its stain resistance.

[0135] By comparing the data in the table, the data in Comparative Examples 11-12 show that the addition of iodomethane and 3-dimethylamino-1,2-propanediol introduces a quaternary ammonium cationic structure into the polyurethane chain segment, forming a uniformly dispersed emulsion. However, when these two substances are not added, the uneven dispersion of the polymer leads to uneven performance, which reduces the coating's stain resistance and hydrophobicity.

[0136] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment 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 within the scope of protection of the present invention.

Claims

1. A flame-retardant and stain-resistant organic-inorganic composite coating for underground coal mine roadways, characterized in that, The flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways is prepared by mixing modified polyurethane emulsion, calcined wollastonite powder, modified inorganic filler, and water glass with water, coating the mixture, and then curing it. The modified polyurethane emulsion is prepared by reacting isophorone diisocyanate with polytetrahydrofuran ether diol and hydroxyl-terminated fluorosilicone oil, then reacting with a chain extender, and finally reacting with iodomethane and adding water. The chain extender includes 3-dimethylamino-1,2-propanediol 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 impregnating the inorganic filler in a conductive slurry; 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 anti-fouling organic-inorganic composite coating for underground coal mine roadways according to claim 1, characterized in that, The inorganic fillers include titanium dioxide, silicon powder, and mica.

3. A method for preparing a flame-retardant and stain-resistant organic-inorganic composite coating for underground coal mine roadways, characterized in that, The preparation steps include the following: (1) Triglycidyl isocyanurate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-methanol-10-oxide and tetrahydrofuran were mixed evenly, heated and stirred under reflux, evaporated by rotary evaporation and dried to obtain a flame retardant chain extender. (2) Weigh out polytetrahydrofuran ether glycol, hydroxyl-terminated fluorosilicone oil and N,N-dimethylformamide and mix them. Under a nitrogen atmosphere, heat up and add isophorone diisocyanate and dibutyltin dilaurate. Stir and react. After taking a sample to confirm that the reaction is complete, cool down and add 3-dimethylamino-1,2-propanediol. After taking a sample to confirm that the reaction is complete, add flame retardant chain extender and heat and stir to react. After taking a sample to confirm that the reaction is complete, add iodomethane and stir to react. Remove N,N-dimethylformamide by vacuum distillation, add pure water and stir at high speed to obtain modified polyurethane emulsion. (3) Under an argon atmosphere, in an ice-water bath, acrylic acid and pure water were mixed, pH was adjusted, acrylonitrile and acrylamide were added, the mixture was stirred at room temperature, ammonium persulfate was added, the mixture was heated and stirred to react, cooled, freeze-dried, ground, washed, filtered, and dried to obtain modified polyacrylic acid adhesive. (4) Mix the modified polyacrylic acid binder and pure water, stir at room temperature, add graphene oxide, stir at room temperature, homogenize under high pressure to obtain a conductive slurry, impregnate the inorganic filler into the conductive slurry, stir at room temperature, take out and drain, dry to obtain the modified inorganic filler. (5) Mix the modified polyurethane emulsion and water, stir, add calcined wollastonite powder, modified inorganic filler and water glass, stir, let stand, coat on the base surface, and cure to obtain a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways.

4. The method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways according to claim 3, characterized in that, The flame retardant chain extender in step (1) is prepared by mixing 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 by mass, stirring and refluxing at 65-70°C and 200-300 r / min for 2-2.5 h, removing the solvent by rotary evaporation, and vacuum drying at 50-60°C for 10-12 h.

5. The method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways according to claim 3, characterized in that, The modified polyurethane emulsion in step (2) is prepared by weighing 10-15 parts of polytetrahydrofuran ether diol, 5-6 parts of hydroxyl-terminated fluorosilicone oil, and 25-30 parts of N,N-dimethylformamide by mass, mixing them evenly, heating to 70-75°C under a nitrogen atmosphere, adding isophorone diisocyanate at a molar ratio of isocyanate to hydroxyl groups of 1:(0.58-0.66), adding 0.12-0.15 parts of dibutyltin dilaurate, reacting at 250-350 r / min for 1.5-2 h, taking samples to confirm complete reaction, cooling to 50-55°C, and adding 3-dimethylamine at a molar ratio of the remaining isocyanate to hydroxyl groups of 1:(0.7-0.75). After reacting with 1,2-propanediol for 1.5-2 hours and confirming complete reaction by sampling, a flame retardant chain extender is added at a molar ratio of (1-1.1):1 of the remaining isocyanate groups to hydroxyl groups. The reaction is carried out at 70-80°C and 300-400 r / min for 2-3 hours. After confirming complete reaction by sampling, iodomethane is added at a molar ratio of 1:(0.7-0.8) of 3-dimethylamino-1,2-propanediol and iodomethane. The reaction is carried out at 25-30°C and 300-400 r / min for 1.5-2 hours. N,N-dimethylformamide is removed by vacuum distillation. 55-75 parts of pure water are added, and the mixture is stirred at 1500-2000 r / min for 40-50 minutes to obtain the final product.

6. The method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways according to claim 3, characterized in that, The modified polyacrylic acid adhesive described in step (3) is prepared by mixing 7-8 parts acrylic acid and 75-80 parts pure water in an ice-water bath under an argon atmosphere, adjusting the pH to 7 with 0.1 mol / L sodium hydroxide aqueous solution, and then adding 2-3 parts acrylonitrile and 4-5 parts acrylamide at room temperature. The mixture is stirred at 200-250 r / min for 10-15 min at room temperature, and then 0.1-0.12 parts ammonium persulfate is added. The mixture is reacted at 60-70℃ and 200-250 r / min for 6-7 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 200-300 r / min for 5-6 h at room temperature. The mixture is then filtered, repeated 3-4 times, and finally vacuum dried at 50-60℃ for 10-12 h.

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

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

9. The method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways according to claim 3, characterized in that, The flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways described in step (5) is prepared by mixing 20 parts of modified polyurethane emulsion and 10 parts of water by mass, stirring at 300-400 r / min for 2-3 min, 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 min, letting stand for 2-3 min, coating on the substrate, and curing at 21-25℃ and 45%RH-70%RH for 168 h.

10. The method for preparing a flame-retardant and anti-fouling organic-inorganic composite coating for underground coal mine roadways according to claim 3, characterized in that, The calcined wollastonite powder in step (5) is obtained by calcining wollastonite powder in an air atmosphere at 900~1100℃ for 2 hours, grinding it, and then passing it through a 325-mesh sieve.

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