A waterproof coating for coating the surface of underground coal mine equipment and its preparation method

Abstract

The present invention relates to the technical field of waterproof coatings, and in particular to a waterproof coating applied on the surface of underground equipment in a coal mine and a preparation method thereof. The waterproof coating comprises the following raw materials in parts by weight: 35-65 parts of organosilicon-modified acrylic emulsion, 5-10 parts of modified multi-walled carbon nanotubes, 15-25 parts of hexachlorotripolyphosphazene derivatives, 1-1.5 parts of film-forming agent, 0.5-1 parts of defoaming agent, 1-1.5 parts of dispersant, 8-15 parts of titanium dioxide, and 5-15 parts of water. The waterproof coating has excellent waterproof performance, flame retardant performance, and corrosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of waterproof coatings, and particularly relates to a waterproof coating for coating the surface of underground coal mine equipment and a preparation method thereof. Background Art

[0002] Coal is an important energy ore. After mining, it can be burned to generate heat energy for utilization, and is widely used in various energy fields such as power generation. Coal mine machinery, electrical equipment and facilities are the basis of coal mine production, including hoisting equipment, ventilation equipment, drainage equipment, mining equipment, power supply and electrical equipment, etc. However, during the construction and production of the mine, surface water and groundwater enter the mine through various channels, which will cause the underground coal mine equipment to be wet, affect the normal operation of the equipment and underground production, and may also cause safety problems. Coating a waterproof coating on the surface of underground coal mine equipment can protect the equipment from the influence of mine water. Therefore, it is very necessary to coat a waterproof coating on the surface of underground coal mine equipment. In addition, fires are likely to occur in underground coal mines, and environmental conditions such as the presence of gas in the roadway require that the waterproof coating on the surface of underground coal mine equipment not only has excellent waterproof performance, but also has good flame retardancy, corrosion resistance, and is environmentally friendly and non-toxic.

[0003] Based on this, it is necessary to further explore the performance of waterproof coatings to better ensure the safety of coal miners. Summary of the Invention

[0004] The first object of the present invention is to provide a waterproof coating for coating the surface of underground coal mine equipment, with excellent waterproof performance, flame retardancy and corrosion resistance.

[0005] The second object of the present invention is to provide a preparation method of a waterproof coating for coating the surface of underground coal mine equipment, which is simple and easy to put into practical production.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A waterproof coating for coating the surface of underground coal mine equipment, comprising the following raw materials in parts by weight: 35 - 65 parts of organosilicon-modified acrylic emulsion, 5 - 10 parts of modified multi-walled carbon nanotubes, 15 - 25 parts of hexachlorocyclotriphosphazene derivatives, 1 - 1.5 parts of film-forming agent, 0.5 - 1 part of defoaming agent, 1 - 1.5 parts of dispersant, 8 - 15 parts of titanium dioxide, and 5 - 15 parts of water.

[0008] Further, the preparation process of the modified multi-walled carbon nanotubes is as follows:

[0009] Adding amino-functionalized multi-walled carbon nanotubes to an aqueous solution of pretreated chitosan for reaction, and obtaining the product after purification.

[0010] Further, the dosage ratio of the amino-functionalized multi-walled carbon nanotubes to the aqueous solution of pretreated chitosan is (0.1~0.5) g : (15~25) mL; the reaction temperature is 40~60 °C, and the reaction time is 2~4 h; the concentration of the aqueous solution of pretreated chitosan is 2~3%, and the pH is 4~4.5.

[0011] Further, the preparation method of the pretreated chitosan is as follows:

[0012] Chitosan is added to an acetic acid aqueous solution and mixed evenly, then a sodium hydroxide solution is added, and a chitosan precipitate is obtained by filtration; after the chitosan precipitate is washed, it is added to a mixed acid solution of nitric acid and phosphoric acid, and then sodium nitrite is added. After shaking at 35~40 °C for 3~4 h, it is washed and dried to obtain the product.

[0013] Further, the dosage ratio of the chitosan to the acetic acid aqueous solution is 1 : (4~6) mL; the volume fraction of the acetic acid aqueous solution is 2%; the concentration of the sodium hydroxide solution is 1.0 mol / L; the dosage ratio of the chitosan precipitate, sodium nitrite, and the mixed acid solution is 1 g : (0.05~0.08) g : (3~4.5) mL; the volume ratio of nitric acid to phosphoric acid in the mixed acid solution is 2 : 1.

[0014] Further, the preparation method of the hexachlorocyclotriphosphazene derivative is as follows:

[0015]

[0016] [1,2,4]Triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine, and thionyl chloride are mixed evenly to obtain a mixed solution; a thionyl chloride solution of hexachlorocyclotriphosphazene is added to the mixed solution for reaction, and after purification, the product is obtained.

[0017] Further, the molar ratio of [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine, and hexachlorocyclotriphosphazene is (6~6.5) : (0.3~0.4) : 1; the reaction temperature is 5~8 °C, and the reaction time is 6~9 h.

[0018] Further, the molar concentration of [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine in the mixed solution is 0.3~0.6 mol / L; the molar concentration of hexachlorocyclotriphosphazene in the thionyl chloride solution of hexachlorocyclotriphosphazene is 0.1~0.4 mol / L.

[0019] Furthermore, the silicone-modified acrylic emulsion is SA-110 modified silicone-acrylic emulsion, the film-forming agent is ethylene glycol monobutyl ether, the defoaming agent is a water-based silicone emulsion defoaming agent, the dispersant is a sodium polyphosphate dispersant, and the titanium dioxide is rutile titanium dioxide.

[0020] Even further, the defoaming agent is BYK-020, the dispersant is BYK-192; the titanium dioxide is TS-6300.

[0021] The preparation method of the waterproof coating applied to the surface of underground coal mine equipment includes the following steps:

[0022] According to the weight ratio, mix the silicone-modified acrylic emulsion, modified multi-walled carbon nanotubes, hexachlorocyclotriphosphazene derivative, film-forming agent, defoaming agent, dispersant, titanium dioxide, and water evenly, then it is done.

[0023] The beneficial technical effects of the present invention are as follows:

[0024] (1) The modified multi-walled carbon nanotubes of the present invention are prepared by pretreating chitosan to introduce carboxyl groups and then reacting with amino-functionalized multi-walled carbon nanotubes. By grafting chitosan onto the multi-walled carbon nanotubes, the dispersibility of the multi-walled carbon nanotubes in the coating is improved; in addition, the modified multi-walled carbon nanotubes of the present invention can also form a uniform protective film on the surface of the substrate, enhancing the densification degree of the coating, effectively blocking the oxidation erosion of the atmosphere on the substrate, and thus significantly improving the corrosion resistance of the coating.

[0025] (2) The present invention synthesizes a hexachlorocyclotriphosphazene derivative with a novel structure and flame retardant properties by using [1,2,4]triazolo[1,5-a][1,3,5]triazine-7-amine and hexachlorocyclotriphosphazene. The above-mentioned hexachlorocyclotriphosphazene derivative contains triazine, triazole groups and phosphazene groups. These functional groups will release non-combustible gases such as carbon dioxide and nitrogen when heated, diluting the concentration of oxygen; in addition, the free radicals generated by the decomposition of the above-mentioned functional groups can also combine with the free radicals in the combustibles, blocking the continuation of the combustion chain, thereby improving the flame retardancy of the coating.

[0026] (3) The test results show that: the coating prepared by the present invention has excellent waterproof performance, flame retardant performance and corrosion resistance.

[0027] (4) The present invention also provides a preparation method of a waterproof coating applied to the surface of underground coal mine equipment. This preparation method is simple and easy to be put into practical production. Specific embodiments

[0028] The following content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention. For the specific conditions not specified in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, unless otherwise specified, are all conventional products obtained through commercial channels.

[0029] The silicone-modified acrylic emulsion of the present invention is SA-110 modified silicone-acrylic emulsion; the film-forming agent is ethylene glycol monobutyl ether; the defoaming agent is BYK-020; the dispersant is BYK-192, and the titanium dioxide is TS-6300.

[0030] Examples

[0031] Example 1

[0032] This example provides a waterproof coating for coating on the surface of underground coal mine equipment. The coating is composed of the following raw materials in parts by weight: 50 parts of SA-110 modified silicone-acrylic emulsion, 7 parts of modified multi-walled carbon nanotubes, 20 parts of hexachlorocyclotriphosphazene derivatives, 1.2 parts of ethylene glycol monobutyl ether, 0.6 part of BYK-020, 1.3 parts of BYK-192, 9 parts of TS-6300, and 10 parts of water.

[0033] Among them, the specific preparation process of the modified multi-walled carbon nanotubes is as follows: According to the dosage ratio of chitosan to acetic acid aqueous solution of 1:5 mL, add chitosan to acetic acid aqueous solution with a volume fraction of 2%, stir and dissolve at 60 °C, then add 1.0 mol / L sodium hydroxide solution to precipitate chitosan, and obtain chitosan precipitate after filtration; wash the chitosan precipitate successively with absolute ethanol and deionized water, and then add it to a mixed acid solution of nitric acid and phosphoric acid (v / v = 2:1), add sodium nitrite, shake and process at 37 °C for 3.5 h, then wash and vacuum dry for 12 h to obtain pretreated chitosan; the dosage ratio of chitosan precipitate, sodium nitrite, and mixed acid solution is 1 g:0.06 g:4 mL.

[0034] According to the dosage ratio of amino-functionalized multi-walled carbon nanotubes to the aqueous solution of pretreated chitosan of 0.2 g:20 mL, add amino-functionalized multi-walled carbon nanotubes to the aqueous solution of pretreated chitosan with a concentration of 2.5% (adjust the pH to 4.2), react at 50 °C for 3 h, wash and vacuum dry for 3 h to obtain modified multi-walled carbon nanotubes.

[0035] The specific preparation process of the hexachlorocyclotriphosphazene derivatives is as follows:

[0036]

[0037] Mix [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine and hexachlorocyclotriphosphazene in a molar ratio of 6:0.3:1, and mix [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine and thionyl chloride evenly to obtain a mixed solution. The molar concentration of [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine in the mixed solution is 0.3 mol / L; add a thionyl chloride solution of hexachlorocyclotriphosphazene with a molar concentration of 0.2 mol / L to the mixed solution, and react at 6 °C for 7 h. After the reaction is completed, filter, wash and dry to obtain a hexachlorocyclotriphosphazene derivative.

[0038] The NMR results of the hexachlorocyclotriphosphazene derivative are as follows:

[0039] 1 1H-NMR(400 MHz, DMSO) δ = 5.47 (s, 6H), 8.64 (s, 6H), 9.39 (s, 6H); Mass spectrometry analysis MS(ESI+): [M+H]+ calculated to be 946.18, found 946.18; The above results confirm that the obtained product is the target product.

[0040] This example also provides a preparation method of the waterproof coating described above for coating on the surface of underground coal mine equipment. The specific preparation process is as follows: Mix SA-110 modified silicone-acrylic emulsion, modified multi-walled carbon nanotubes, hexachlorocyclotriphosphazene derivative, BYK-020, BYK-020, BYK-192, TS-6300 and water evenly according to the above weight ratio.

[0041] Example 2

[0042] This example provides a waterproof coating for coating on the surface of underground coal mine equipment. The coating is composed of the following raw materials in parts by weight: 65 parts of SA-110 modified silicone-acrylic emulsion, 10 parts of modified multi-walled carbon nanotubes, 25 parts of hexachlorocyclotriphosphazene derivative, 1.5 parts of ethylene glycol monobutyl ether, 1 part of BYK-020, 1.5 parts of BYK-192, 15 parts of TS-6300, and 15 parts of water.

[0043] Among them, the specific preparation process of the modified multi-walled carbon nanotubes is as follows: According to the dosage ratio of chitosan to acetic acid aqueous solution of 1:6 mL, chitosan is added to the acetic acid aqueous solution with a volume fraction of 2%, stirred and dissolved at 60 °C, and then 1.0 mol / L sodium hydroxide solution is added to precipitate chitosan. After filtration, chitosan precipitate is obtained; the chitosan precipitate is washed successively with absolute ethanol and deionized water and then added to a mixed acid solution of nitric acid and phosphoric acid (v / v = 2:1), and then sodium nitrite is added. After shaking treatment at 40 °C for 3 h, it is washed and vacuum dried for 12 h to obtain pretreated chitosan; the dosage ratio of chitosan precipitate, sodium nitrite, and mixed acid solution is 1 g:0.08 g:4.5 mL.

[0044] According to the dosage ratio of amino-functionalized multi-walled carbon nanotubes to the aqueous solution of pretreated chitosan of 0.5 g:25 mL, amino-functionalized multi-walled carbon nanotubes are added to the aqueous solution of pretreated chitosan with a concentration of 3% (adjust the pH to 4.5), and the reaction is carried out at 60 °C for 2 h. After washing and vacuum drying for 3 h, modified multi-walled carbon nanotubes are obtained.

[0045] The specific preparation process of the hexachlorocyclotriphosphazene derivative is as follows:

[0046]

[0047] According to the molar ratio of [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine, and hexachlorocyclotriphosphazene of 6.5:0.4:1, [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine, and thionyl chloride are mixed evenly to obtain a mixed solution, and the molar concentration of [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine in the mixed solution is 0.5 mol / L; a thionyl chloride solution of hexachlorocyclotriphosphazene with a molar concentration of 0.4 mol / L is added to the mixed solution, and the reaction is carried out at 8 °C for 6 h. After the reaction is completed, it is filtered, washed, and dried to obtain the hexachlorocyclotriphosphazene derivative.

[0048] This embodiment also provides a preparation method of the waterproof coating applied to the surface of underground coal mine equipment. The specific preparation process is as follows: According to the above weight ratio, SA-110 modified silicone-acrylic emulsion, modified multi-walled carbon nanotubes, hexachlorocyclotriphosphazene derivative, BYK-020, BYK-020, BYK-192, TS-6300, and water are mixed evenly.

[0049] Example 3

[0050] This embodiment provides a waterproof coating applied to the surface of underground coal mine equipment. The coating is composed of the following raw materials in parts by weight: 35 parts of SA-110 modified silicone-acrylic emulsion, 5 parts of modified multi-walled carbon nanotubes, 15 parts of hexachlorocyclotriphosphazene derivative, 1 part of ethylene glycol monobutyl ether, 0.5 part of BYK-020, 1 part of BYK-192, 8 parts of TS-6300, and 5 parts of water.

[0051] Among them, the specific preparation process of the modified multi-walled carbon nanotubes is as follows: According to the dosage ratio of chitosan to acetic acid aqueous solution of 1:4 mL, chitosan is added to acetic acid aqueous solution with a volume fraction of 2%, stirred and dissolved at 60 °C, and then 1.0 mol / L sodium hydroxide solution is added to precipitate chitosan. After filtration, chitosan precipitate is obtained; the chitosan precipitate is successively washed with absolute ethanol and deionized water and then added to a mixed acid solution of nitric acid and phosphoric acid (v / v = 2:1), and sodium nitrite is added. After shaking treatment at 35 °C for 4 h, it is washed and vacuum dried for 12 h to obtain pretreated chitosan; the dosage ratio of chitosan precipitate, sodium nitrite, and mixed acid solution is 1 g:0.065 g:3 mL.

[0052] According to the dosage ratio of amino-functionalized multi-walled carbon nanotubes to the aqueous solution of pretreated chitosan of 0.1 g:15 mL, amino-functionalized multi-walled carbon nanotubes are added to the aqueous solution of pretreated chitosan with a concentration of 2% (adjust the pH to 4), and the reaction is carried out at 40 °C for 4 h. After washing and vacuum drying for 3 h, modified multi-walled carbon nanotubes are obtained.

[0053] The specific preparation process of the hexachlorocyclotriphosphazene derivative is as follows:

[0054]

[0055] According to the molar ratio of [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine, and hexachlorocyclotriphosphazene of 6:0.3:1, [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine, 4-dimethylaminopyridine, and thionyl chloride are mixed evenly to obtain a mixed solution, and the molar concentration of [1,2,4]triazolo[1,5-a][1,3,5]triazin-7-amine in the mixed solution is 0.6 mol / L; a thionyl chloride solution of hexachlorocyclotriphosphazene with a molar concentration of 0.1 mol / L is added to the mixed solution, and the reaction is carried out at 5 °C for 9 h. After the reaction is completed, it is filtered, washed, and dried to obtain the hexachlorocyclotriphosphazene derivative.

[0056] This embodiment also provides a preparation method of the waterproof coating applied to the surface of underground coal mine equipment. The specific preparation process is as follows: According to the above weight ratio, mix SA-110 modified silicone-acrylic emulsion, modified multi-walled carbon nanotubes, hexachlorocyclotriphosphazene derivatives, BYK-020, BYK-020, BYK-192, TS-6300, and water evenly, and that's it.

[0057] Comparative example

[0058] Comparative example 1

[0059] This comparative example provides a coating, which is different from that of Example 1 in that: chitosan and aminated multi-walled carbon nanotubes are used instead of modified multi-walled carbon nanotubes, and the mass ratio of chitosan to aminated multi-walled carbon nanotubes is 2:5, and the rest is the same as that of Example 1.

[0060] Comparative example 2

[0061] This comparative example provides a coating, which is different from that of Example 1 in that: the pretreatment process of chitosan is omitted, and chitosan is used instead of pretreated chitosan to be mixed with aminated multi-walled carbon nanotubes, and the specific process conditions are the same as those of the preparation process of modified multi-walled carbon nanotubes in Example 1.

[0062] Comparative example 3

[0063] This comparative example provides a coating, which is different from that of Example 1 in that: multi-walled carbon nanotubes are used instead of aminated multi-walled carbon nanotubes to be mixed with pretreated chitosan, and the specific process conditions are the same as those of the preparation process of modified multi-walled carbon nanotubes in Example 1.

[0064] Comparative example 4

[0065] This comparative example provides a coating, which is different from that of Example 1 in that: hexachlorocyclophosphine is used instead of hexachlorocyclotriphosphazene derivatives, and the rest is the same as that of Example 1.

[0066] The performance of the coating prepared by the present invention is described below.

[0067] Test example

[0068] Explore the waterproof, flame retardant and corrosion resistance of the coatings prepared in Examples 1-3 and Comparative Examples 1-4. The specific test process is as follows:

[0069] . Waterproof performance

[0070] Coat the coatings prepared in Examples 1-3 and Comparative Examples 1-4 on a glass substrate to obtain a coating with a thickness of 5 mm, and use a JC2000C type dynamic contact angle measuring instrument to measure the water contact angle θ on the surface of each coating. The results are shown in Table 1.

[0071] . Flame retardancy performance

[0072] The limiting oxygen index of the coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 4 was detected according to GB / T 23445 - 2009, and the results are shown in Table 1.

[0073] . Corrosion resistance performance

[0074] The coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 4 were made into test plates with specified dimensions and thicknesses by roll coating according to the required dimensions of the test samples. After curing at 50°C for 7 days, the corrosion resistance was tested according to Method A of GB / T 9274 - 1988. The judgment criterion was that no blistering, rusting, cracking, or peeling occurred on each plate after soaking for 30 days, and it was considered passed. Among them, the technical index for acid resistance was a mixed solution of 5% hydrochloric acid and 5% sulfuric acid; the technical index for chemical resistance detection was a 5% sodium nitrite solution; the technical index for alkali resistance detection was a 5% NaOH solution, and the results are shown in Table 1.

[0075] Table 1

[0076]

[0077] It can be seen from Table 1 that the coatings prepared in Examples 1 - 3 have excellent waterproof, flame retardant, and corrosion resistance performances.

[0078] Compared with Examples 1 - 3, the waterproof and corrosion resistance performances of the coatings prepared in Comparative Examples 1 - 3 were significantly reduced. Further analysis shows that in the present invention, carboxylic acid groups were introduced by pre - treating chitosan, and then it reacted with the amino groups on the amino - functionalized multi - walled carbon nanotubes, so that chitosan was grafted onto the multi - walled carbon nanotubes, thereby improving the dispersion of multi - walled carbon nanotubes in the coating. In addition, the modified multi - walled carbon nanotubes of the present invention can also form a highly uniform protective film on the surface of the substrate, which not only enhances the densification degree of the coating but also effectively blocks the oxidation and erosion of the matrix by the atmospheric environment, thus significantly improving the corrosion resistance of the coating.

[0079] Compared with Examples 1 - 3, the flame retardancy performance of the coating prepared in Comparative Example 4 was significantly reduced. Further analysis shows that the hexachlorocyclotriphosphazene derivative synthesized from [1,2,4]triazolo[1,5 - a][1,3,5]triazine - 7 - amine and hexachlorocyclotriphosphazene contains triazine, triazole groups, and phosphazene groups. These functional groups will release non - combustible gases such as carbon dioxide and nitrogen when heated, diluting the concentration of oxygen. In addition, these functional groups can also generate free radicals through decomposition and combine with the free radicals in the combustibles to block the continuation of the combustion chain, thereby improving the flame retardancy of the coating.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. The basic principles and main features of the present invention have been described in the above with specific implementation schemes. On the basis of the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of protection required by the present invention.

Claims

1. A waterproof coating applied on the surface of underground equipment in a coal mine, characterized in that: The invention comprises the following raw materials in parts by weight: 35-65 parts of organosilicon-modified acrylic emulsion, 5-10 parts of modified multi-walled carbon nanotubes, 15-25 parts of hexachlorotripolyphosphazene derivatives, 1-1.5 parts of film-forming agent, 0.5-1 parts of defoaming agent, 1-1.5 parts of dispersant, 8-15 parts of titanium dioxide, and 5-15 parts of water; The preparation process of the modified multi-walled carbon nanotubes is as follows: adding amino-modified multi-walled carbon nanotubes to an aqueous solution of pretreated chitosan to react, and obtaining the modified multi-walled carbon nanotubes after purification; The preparation method of the hexachlorotriphosphazene derivative is as follows: [1,2,4]triazolo[1,5-A][1,3,5]triazine-7-amine, 4-dimethylaminopyridine and dichlorothionyl are uniformly mixed to obtain a mixed solution; a dichlorothionyl solution of hexachlorotriphosphazene is added to the mixed solution for reaction, and the obtained product is obtained after purification.

2. The waterproof coating applied to the surface of underground equipment in a coal mine according to claim 1, characterized in that: The dosage ratio of the amino multi-walled carbon nanotubes and the aqueous solution of pretreated chitosan is (0.1-0.5) g: (15-25) mL; the reaction temperature is 40-60° C., and the reaction time is 2-4 hours; the concentration of the aqueous solution of pretreated chitosan is 2-3%, and the pH is 4-4.

5.

3. The waterproof coating applied to the surface of underground equipment in a coal mine according to claim 2, characterized in that: The preparation method of the pretreated chitosan is as follows: adding chitosan to an acetic acid aqueous solution and mixing evenly, then adding a sodium hydroxide solution, filtering to obtain a chitosan precipitate; washing the chitosan precipitate, adding it to a mixed acid solution of nitric acid and phosphoric acid, then adding sodium nitrite, shaking at 35-40° C. for 3-4 hours, washing, and drying to obtain the pretreated chitosan.

4. The waterproof coating applied to the surface of underground equipment in a coal mine according to claim 3, characterized in that: The volume fraction of the acetic acid aqueous solution is 2%; the concentration of the sodium hydroxide solution is 1.0 mol / L; the dosage ratio of the chitosan precipitate, sodium nitrite, and mixed acid solution is 1 g: (0.05-0.08) g: (3-4.5) mL; and the volume ratio of nitric acid to phosphoric acid in the mixed acid solution is 2:

1.

5. The waterproof coating applied to the surface of underground equipment in a coal mine according to claim 1, characterized in that: The molar ratio of [1,2,4]triazolo[1,5-A][1,3,5]triazine-7-amine, 4-dimethylaminopyridine and hexachlorotripolyphosphazene is (6-6.5):(0.3-0.4):1; the reaction temperature is 5-8°C and the reaction time is 6-9h.

6. The waterproof coating applied to the surface of underground equipment in a coal mine according to claim 1, characterized in that: The molar concentration of [1,2,4]triazolo[1,5-A][1,3,5]triazine-7-amine in the mixed solution is 0.3-0.6 mol / L; the molar concentration of hexachlorotripolyphosphazene in the dichlorothionyl solution of hexachlorotripolyphosphazene is 0.1-0.4 mol / L.

7. The waterproof coating applied to the surface of underground equipment in a coal mine according to claim 1, characterized in that: The organosilicon-modified acrylic emulsion is SA-110 modified silicone-acrylic emulsion, the film-forming agent is ethylene glycol butyl ether, the defoaming agent is a water-based organosilicon emulsion defoaming agent, the dispersant is a sodium polyphosphate dispersant, and the titanium dioxide is rutile titanium dioxide.

8. The method for preparing the waterproof coating applied on the surface of underground equipment in coal mines according to any one of claims 1 to 7, characterized in that: The following steps are involved: According to the above weight ratio, the organosilicon-modified acrylic emulsion, the modified multi-walled carbon nanotubes, the hexachlorotripolyphosphazene derivative, the film-forming agent, the defoaming agent, the dispersant, the titanium dioxide and the water are uniformly mixed.

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