Breathable hole-protecting material suitable for underground environment of coal mine and preparation method of breathable hole-protecting material

Abstract

The invention provides a breathable hole-protecting material suitable for an underground coal mine environment and a preparation method thereof, and the preparation method comprises the following steps: dispersing a polymer monomer and an emulsifier in a water phase, and adding a surfactant to obtain a first solution; dispersing the first solution in an oil phase, adding a curing agent, and uniformly stirring to obtain a grouting material; drilling and grouting the grouting material, and curing at normal temperature to form a breathable hole protecting material; wherein the mass ratio of the polymer monomer to the curing agent is 4: (1-2.4); the mass ratio of the oil phase to the polymer monomer is (3.5-5): 1; the mass ratio of the polymer monomer to the water phase is (1-4): 1. The preparation method does not involve high temperature, microwave, laser and other operations, the reaction is mild, the grouting operation can be met, the heat release in the process is low, and the safe use condition of a coal mine is met. The breathable hole-protecting material provided by the invention has a breathable characteristic, the bearing strength is greater than or equal to 2MPa, and the breathable hole-protecting material can functionally meet the requirements of gas extraction drilling and hole protection.

Description

Technical Field

[0001] The present application relates to the technical field of mine gas extraction, and in particular to a breathable pore-protecting material suitable for underground coal mine environments and a preparation method thereof. Background Art

[0002] At present, drilling and gas extraction is the main measure of gas control technology. However, during the gas extraction process, due to the complexity of geological conditions and the influence of mining dynamic pressure, the gas extraction borehole will be deformed, blocked or even collapsed, affecting the gas extraction effect, which leads to the demand for borehole protection. Borehole protection is mainly divided into casing protection and grouting material protection. At present, the most basic way of borehole protection is screen tube protection, but it has different degrees of problems such as complex construction process, long construction period, high labor intensity and short construction distance. Grouting hole protection can overcome the difficulties of screen tube hole protection process, and the reaction strength can be guaranteed to be at least 2MPa, which completely exceeds the compressive strength of the existing commonly used hole protection flower pipe, and realizes long-term support for the borehole wall.

[0003] At present, the main material for protecting the boreholes used in gas extraction in mines is cement. Ordinary cement does not have air permeability after solidification. When used for borehole protection, it will hinder the flow of gas on both sides of the borehole, causing gas accumulation and posing a safety hazard. In the related technology, gas generated by the reaction of chemical reagents such as sodium bicarbonate and hydrogen peroxide is used to make holes. Due to the limited amount of generated gas, the pores formed are small and the air permeability is greatly reduced. The mine-use breathable hole protection materials produced by this process method are difficult to promote and apply on a large scale. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the related art to a certain extent. The present application proposes a breathable pore-protecting material suitable for underground coal mine environments and a preparation method thereof, which can be used for operations in underground coal mine environments, has a controllable curing time to meet the requirements of grouting operations, and has high mechanical strength (≥2MPa) and good air permeability after curing.

[0005] According to an embodiment of the first aspect of the present application, a method for preparing a breathable pore-protecting material suitable for an underground coal mine environment is proposed, comprising the following steps:

[0006] Dispersing polymer monomers and emulsifiers in an aqueous phase, and adding a surfactant to obtain a first solution;

[0007] Dispersing the first solution in the oil phase and adding a curing agent and stirring evenly to obtain a grouting material; and

[0008] Drilling and grouting the grouting material and solidifying it at room temperature to form a breathable hole-protecting material;

[0009] Among them, the mass ratio of the polymer monomer to the curing agent is 4:(1-2.4); the mass ratio of the oil phase to the polymer monomer is (3.5-5):1; the mass ratio of the polymer monomer to the water phase is (1-4):1.

[0010] In some embodiments, the polymer monomer comprises an epoxy resin.

[0011] In some embodiments, the curing agent is a room temperature curing agent, including at least one of a phenolic amine epoxy curing agent, an epoxy resin curing agent, or 2,4,6-tris(dimethylaminomethyl)phenol.

[0012] In some embodiments, the oil phase includes at least one of polyethylene glycol, 1,4-dioxane, dimethylformamide, cyclohexanone, and dimethyl sulfoxide.

[0013] In some embodiments, the amount of the emulsifier added is no more than 25% of the mass of the polymer monomer;

[0014] And / or, the emulsifier includes at least one of polyethylene glycol 6000, polysorbate 80, trimethylolpropane glycidyl ether, epoxy resin and boron trifluoride ether complex.

[0015] In some embodiments, the mass ratio of the polymer monomer to the surfactant is less than 100;

[0016] And / or, the surfactant includes at least one of hexadecyltrimethylammonium bromide, polyvinylpyrrolidone, sodium bis(2-ethylhexyl)succinate sulfonate, and didodecyldimethylammonium bromide.

[0017] In some embodiments, the polymer monomer and the emulsifier are dispersed in the water phase in a parameter of: a mass ratio of the polymer monomer, the emulsifier, and the water phase is 10:(3-10).

[0018] In some embodiments, the grouting material is drilled and grouted and cured at room temperature for 10-15 hours to form a breathable and pore-protecting material.

[0019] The preparation method of the embodiment of the present application first utilizes the emulsion method to uniformly disperse the polymer monomer in the aqueous phase to form a first solution. The aqueous phase in the first solution can also form a breathable channel after the solidification is completed and removed, further increasing the size of the interconnected pores formed by the oil phase, improving the air permeability, while also reducing the amount of oil phase used and shortening the curing time. In addition, the present application utilizes the reaction-induced phase separation method to solidify the polymer monomer. As the polymer solidifies, the compatibility with the oil phase deteriorates, and phase separation occurs. By accurately controlling the ratio of the oil phase to the polymer monomer, a bicontinuous structure can be formed, and a breathable channel is formed after the solidification is completed. The porous material obtained by this method is mostly used in membrane emulsification. In addition, the size of the pores formed in the reaction-induced phase separation method is relatively small, and the addition of the oil phase will greatly prolong the curing time at room temperature, which will cause the stratification of the material during the curing process on the one hand, and affect the sealing efficiency on the other hand.

[0020] The present application creatively combines the emulsion method with the reaction-induced phase separation method, uniformly disperses the polymer monomer in the aqueous phase to form an emulsion-like first solution, and the aqueous phase in the first solution is removed after solidification. If the preparation method of the breathable pore-protecting material only uses the emulsion method, the cured material will shrink significantly and will not form a bicontinuous structure. This is because the surface tension of the aqueous phase and the polymer is quite different. During the solidification process, the aqueous phase is compressed out of the structure; in addition, the aqueous phase is easy to evaporate, and water is lost before the polymer structure is solidified and formed. If the preparation method of the breathable pore-protecting material only uses the reaction-induced phase separation method, the curing time of the polymer will be greatly prolonged (>48h). Too long a curing time will cause uneven density distribution of the material, affecting the material performance. Therefore, the preparation method provided in the present application does not involve high temperature, microwave, laser and other operations, and the reaction is mild, which can meet the grouting operation and the process has low heat release, meeting the safe use conditions of coal mines.

[0021] According to an embodiment of the second aspect of the present application, a breathable and pore-protecting material suitable for underground coal mine environments is proposed, which is obtained by the preparation method described in any of the above embodiments, and includes a polymer monomer, a curing agent, an oil phase, an aqueous phase, an emulsifier and a surfactant; wherein the mass ratio of the polymer monomer to the curing agent is 4:(1-2.4); the mass ratio of the oil phase to the polymer monomer is (3.5-5):1; the mass ratio of the polymer monomer to the aqueous phase is (1-2.5):1; the amount of the emulsifier added is not higher than 25% of the mass of the polymer monomer; the mass ratio of the polymer monomer to the surfactant is less than 100.

[0022] In some embodiments, the breathable pore-protecting material has a connected pore structure, and the mechanical pressure bearing strength is ≥ 2 MPa.

[0023] The breathable pore-protecting material provided in the present application can be used for drilling and grouting operations while having a certain mechanical strength (≥2MPa); in addition, the breathable pore-protecting material has a connected pore structure, is breathable, and has a controllable curing time.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 is a flow chart of a method for preparing a breathable pore-protecting material according to an embodiment of the present application;

[0027] Figure 2 is a SEM image of a breathable pore-protecting material according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the present application includes all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0029] At present, the existing grouting mine hole protection materials are generally cement-based materials. The permeability modification of cement-based materials is achieved by adding multi-level aggregates to form holes. This method is not suitable for drilling and grouting. Porous materials with certain mechanical strength are widely used in other fields, including porous glass, porous ceramics, porous polymers, etc. Among them, the formation of porous structures of glass and ceramic materials generally requires high-temperature treatment. The underground environment of coal mines is special. From the perspective of coal mine safety, high-temperature operations are not allowed underground. The formation of polymer porous structures is generally achieved by adding foaming agents. Since the stability time of the bubbles formed is short, the polymer prepared by this method has a high curing rate and is not suitable for grouting operations. At the same time, the heat release is large in a short time, and coal mine safety accidents are prone to occur when used in areas with high gas concentrations. Therefore, the existing breathable porous materials cannot be used for underground drilling and hole protection in coal mines. This is because the pore formation of most porous materials requires certain reaction conditions, including high temperature, microwave, laser and other conditions, which are not suitable for underground operations.

[0030] The technical solution of the embodiment of the present application provides a breathable hole-protecting material suitable for underground coal mine environments and a preparation method thereof. The preparation process does not involve high temperature, microwave, laser and other operations, the reaction is mild, and the grouting operation can be satisfied. The process releases low heat and meets the safe use conditions of coal mines. The breathable hole-protecting material formed after grouting and curing has air permeability and a pressure bearing strength of ≥2MPa, and can functionally meet the requirements of gas extraction drilling hole protection.

[0031] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0032] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0033] To achieve the above-mentioned purpose, according to the embodiment of the first aspect of the present application, a method for preparing a breathable pore-protecting material suitable for underground coal mine environment is proposed. Figure 1 , including the following steps:

[0034] S1: dispersing polymer monomers and emulsifiers in an aqueous phase, and adding a surfactant to obtain a first solution;

[0035] S2: dispersing the first solution in the oil phase and adding a curing agent and stirring evenly to obtain a grouting material; and

[0036] S3: drilling and grouting the grouting material and solidifying it at room temperature to form a breathable hole-protecting material;

[0037] Among them, the mass ratio of polymer monomer to curing agent is 4:(1-2.4); the mass ratio of oil phase to polymer monomer is (3.5-5):1; the mass ratio of polymer monomer to water phase is (1-4):1.

[0038] Among them, in S1, the polymer monomer and the emulsifier are first uniformly dispersed in the aqueous phase under stirring conditions using an emulsion method, for example, a high shear homogenizer is used for processing for 15-45 minutes, and a surfactant is added to form a first solution, wherein the polymer monomer includes an epoxy resin, and the emulsifier includes at least one of polyethylene glycol 6000, polysorbate 80, trimethylolpropane glycidyl ether, epoxy resin and boron trifluoride ether complex, and the added amount is not higher than 25% of the mass of the polymer monomer; that is, based on the polymer monomer, the mass percentage of the emulsifier is 0.1%, 0.5%, 0.8%, etc., wherein the role of the emulsifier is to uniformly disperse the polymer monomer in the aqueous phase to form an emulsion.

[0039] The aqueous phase in the present application may be an aqueous solution, wherein the mass ratio of the polymer monomer to the aqueous phase is (1-4):1, and the exemplified mass ratio of the polymer monomer to the aqueous phase is (1, 2, 3):1, etc., wherein a small amount of polymer monomer is added, and the pore size of the formed pore-protecting material is larger, and the air and water permeability is large, but the pore wall of the formed skeleton material is thinner, and the mechanical strength of the material is lower, which does not meet the requirements of high-strength pore protection; if a large amount of polymer monomer is added, the relative addition ratio of the diluent is lower, and the formed pore size is smaller and the pore wall is thicker, resulting in small air and water permeability, but excellent mechanical properties.

[0040] In some embodiments, the surfactant includes at least one of hexadecyl trimethyl ammonium bromide, polyvinyl pyrrolidone, sodium bis (2-ethylhexyl) succinate sulfonate, and didodecyl dimethyl ammonium bromide. The surfactant can improve the uniformity of the dispersion of the polymer monomer in the aqueous phase, wherein the mass ratio of the polymer monomer to the surfactant is less than 100. The addition of the surfactant is to compensate for the effect of the emulsifier, which is beneficial to improve the uniform dispersion of the polymer monomer in water. On the other hand, it can reduce the surface tension between the polymer and water, and can reduce the water being squeezed out of the pores during the curing process, causing the pore structure to shrink and become smaller. Therefore, a small amount of additives will cause uneven dispersion of the polymer monomer on the one hand, and may cause shrinkage of the pore structure on the other hand; a large amount of additives will introduce a large number of bubbles during the stirring process, affecting the preparation of the material.

[0041] In this step, the polymer monomer is uniformly dispersed in the water phase to form a first milky solution, and the water phase in the first solution is removed after solidification. After solidification, the water phase in the first solution can also form a breathable channel, further increasing the size of the interconnected pores formed by the oil phase, improving the air permeability, while also reducing the amount of oil phase used and shortening the curing time.

[0042] In S2, the first solution is dispersed in the oil phase by reaction induced phase separation, wherein the oil phase includes at least one of polyethylene glycol, 1,4-dioxane, dimethylformamide, cyclohexanone, and dimethyl sulfoxide, and the mass ratio of the oil phase to the polymer monomer in the first solution is (3.5-5):1, for example, the mass ratio of the oil phase to the polymer monomer in the first solution is (3.5, 4, 4.5, 5):1, etc.

[0043] After the first solution is evenly dispersed in the oil phase, an appropriate amount of curing agent is added and stirred evenly to obtain a grouting material, wherein the curing agent is a room temperature curing agent, including at least one of a phenolic amine epoxy curing agent, an epoxy resin curing agent or 2,4,6-tris(dimethylaminomethyl)phenol, and the mass ratio of the polymer monomer to the curing agent in the first solution is 4:(1-2.4), for example, the mass ratio of the polymer monomer to the curing agent in the first solution is 4:(1, 1.4, 2, 2.4), etc.; when the mass ratio of the polymer monomer to the curing agent is too large, the curing time will be prolonged, and the polymer will settle during the curing process, resulting in uneven density of the pore protection material; on the contrary, when the mass ratio of the polymer monomer to the curing agent is too small, the curing agent is relatively excessive, which is economically unsuitable.

[0044] In this step, the polymer monomer is solidified by the reaction-induced phase separation method. As the polymer solidifies, the compatibility with the oil phase deteriorates and phase separation occurs. By precisely controlling the ratio of the oil phase to the polymer monomer, a bicontinuous structure can be formed. After solidification, air-permeable channels are formed. The porous materials obtained by this method are mostly used in membrane emulsification. In addition, the size of the pores formed in the reaction-induced phase separation method is small, and the addition of the oil phase will greatly prolong the solidification time at room temperature, which will cause stratification of the material during the solidification process on the one hand, and affect the sealing efficiency on the other hand.

[0045] In S3, the grouting material is drilled and grouted and solidified at room temperature to form a breathable hole-protecting material, that is, after the drilling and grouting, the grouting material is solidified at room temperature for a certain period of time to form a breathable hole-protecting material.

[0046] Therefore, the present application creatively combines the emulsion method with the reaction-induced phase separation method, uniformly disperses the polymer monomer in the aqueous phase to form an emulsion-like first solution, and the aqueous phase in the first solution is removed after solidification. If the preparation method of the breathable pore-protecting material only uses the emulsion method, the cured material will shrink significantly and will not form a bicontinuous structure. This is because the surface tension of the aqueous phase and the polymer is quite different. During the solidification process, the aqueous phase is compressed out of the structure; in addition, the aqueous phase is easy to evaporate, and water is lost before the polymer structure is solidified and formed. If the preparation method of the breathable pore-protecting material only uses the reaction-induced phase separation method, the curing time of the polymer will be greatly prolonged (>48h). Too long a curing time will cause uneven density distribution of the material, affecting the material performance. Therefore, the preparation method provided in the present application does not involve high temperature, microwave, laser and other operations, and the reaction is mild, which can meet the grouting operation and the process has low heat release, meeting the safe use conditions of coal mines.

[0047] According to the embodiment of the second aspect of the present application, a breathable and pore-protecting material suitable for underground coal mine environments is proposed, which is obtained by the preparation method in any of the above embodiments, and includes a polymer monomer, a curing agent, an oil phase, an aqueous phase, an emulsifier and a surfactant; wherein the mass ratio of the polymer monomer to the curing agent is 4:(1-2.4); the mass ratio of the oil phase to the polymer monomer is (3.5-5):1; the mass ratio of the polymer monomer to the aqueous phase is (1-4):1; the amount of the emulsifier added is not higher than 25% of the mass of the polymer monomer; and the mass ratio of the polymer monomer to the surfactant is less than 100.

[0048] Among them, the polymer monomer includes epoxy resin; the curing agent is a room temperature curing agent, including at least one of phenolic amine epoxy curing agent, epoxy resin curing agent or 2,4,6-tris(dimethylaminomethyl)phenol; the oil phase includes at least one of polyethylene glycol, 1,4-dioxane, dimethylformamide, cyclohexanone, and dimethyl sulfoxide; the emulsifier includes at least one of polyethylene glycol 6000, polysorbate 80, trimethylolpropane glycidyl ether, epoxy resin and boron trifluoride ether complex; the surfactant includes at least one of hexadecyltrimethylammonium bromide, polyvinylpyrrolidone, sodium bis(2-ethylhexyl) succinate sulfonate, and didodecyldimethylammonium bromide; the aqueous phase can be an aqueous solution.

[0049] The breathable pore-protecting material provided in the present application can be used for drilling and grouting operations while having a certain mechanical strength (≥2MPa); in addition, the breathable pore-protecting material has a connected pore structure, is breathable, and has a controllable curing time.

[0050] To facilitate further understanding of the present application, the scheme of the present application is further described below in conjunction with the embodiments. Those skilled in the art will understand that the description in the present application is only part of the examples, and any other suitable specific examples are within the scope of the present application.

[0051] Example 1

[0052] The present embodiment provides a method for preparing a breathable and pore-protecting material suitable for underground coal mine environments, and the preparation method and specific operating parameters are as follows: disperse epoxy resin monomer and emulsifier in an aqueous phase under stirring conditions according to a mass ratio, and add a surfactant to obtain a first solution; disperse the first solution in polyethylene glycol 200 and add phenolic amine (PAA) epoxy curing agent and stir evenly to obtain a grouting material; finally, drill and grout the grouting material and cure it at room temperature to form a breathable and pore-protecting material; wherein, based on the breathable and pore-protecting material, in terms of mass percentage, it includes 16.4% epoxy resin monomer; 16.4% aqueous phase; 56.4% polyethylene glycol 200; 9.8% phenolic amine (PAA) epoxy curing agent; 0.8% emulsifier; and 0.2% surfactant. The breathable and pore-protecting material obtained in this embodiment was scanned using a scanning electron microscope to obtain the following: Figure 2 The structural morphology of the breathable pore-protecting material shown in the figure, the brighter area is the epoxy resin skeleton formed, and the darker area is the pores formed. Figure 2 It can be seen that the epoxy resin material with a continuous pore structure can be prepared by the method of this embodiment.

[0053] According to the indicators in Table 1, the addition amounts of epoxy resin monomer, water phase, oil phase and phenolaldehyde amine (PAA) epoxy curing agent were adjusted in each embodiment and comparative example.

[0054] Table 1 Components and addition amounts of breathable pore-protecting materials in various embodiments and comparative examples

[0055] Polymer monomer Water Phase oil phase Curing agent Emulsifier Surfactants Example 2 14.6 4.9 70.8 8.7 0.8 0.2 Example 3 15.2 7.6 67.2 9 0.8 0.2 Example 4 16 8 71 4 0.8 0.2 Comparative Example 1 19.8 / 68.3 11.9 / / Comparative Example 2 37.6 37.6 / 22.5 1.8 0.5

[0056] Experimental example

[0057] The breathable pore-protecting materials in the embodiments and comparative examples were subjected to air permeability tests and mechanical strength tests. The breathable pore-protecting materials have relatively large air passages and are permeable to air and water, and the water permeability is used to characterize the air permeability.

[0058] The breathable pore-protecting materials in the embodiments and comparative examples are prepared into cylindrical shapes, the diameter of the cylinder being consistent with the inner diameter of a 500ml mineral water bottle mouth, and the length of the cylinder being 1cm. 200ml of water is placed in the mineral water bottle, the mouth of the mineral water bottle is plugged with the cylindrical pore-protecting material, and glue is applied to the edge where the material contacts the bottle mouth. The mineral water bottle is inverted, and the amount of liquid leakage for 2 hours is recorded to detect the air permeability.

[0059] In addition, the cured breathable pore-protecting materials in the embodiments and comparative examples were cut into cubes of 5 cm×5 cm×5 cm, and the compressive strength of the materials was tested using a compression testing machine. The results are shown in Table 2.

[0060] Table 2 Test results of breathable pore-protecting materials in various embodiments and comparative examples

[0061] Water permeability / ml Strength / MPa Curing time / h Example 1 12 2.8 10 Example 2 13 3 14 Example 3 16 3.1 13 Example 4 15 3 12 Comparative Example 1 8 3.4 9 Comparative Example 2 / / 8

[0062] From the results in Table 2, it can be seen that the higher the amount of polymer monomer added, the smaller the pore structure formed, and the smaller the water permeability; the change of the synthesis parameters in this patent has little effect on the strength of the material, but the larger the amount of water phase added, the greater the effect on the mechanical properties of the material. This is because the emulsion method will significantly improve the pore structure formed by the reaction-induced phase separation method, and the large pores will reduce the mechanical strength of the material; the curing rate is related to the dilution degree of the polymer monomer and the amount of curing agent added. The greater the dilution degree, the longer the curing time, so the curing time of Example 2 is the longest, followed by Example 3; Example 1 has a shorter curing time than Example 4, which is due to the large amount of curing agent added in Example 1. Comparative Example 1 is a pore-protecting material prepared by the reaction-induced phase separation method, and Comparative Example 2 is a pore-protecting material prepared by the emulsion method. The water permeability of Comparative Example 1 is obviously the lowest, but the strength is the highest, indicating that the pore structure size of the pore-protecting material prepared by the reaction-induced phase separation method is smaller and the pore wall is thicker; the pore-protecting material prepared by Comparative Example 2 collapses visibly and cannot form a complete structure in the mold.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0064] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for preparing a breathable and pore-protecting material suitable for underground coal mine environments, characterized in that: The following steps are involved: Dispersing polymer monomers and emulsifiers in an aqueous phase, and adding a surfactant to obtain a first solution; Dispersing the first solution in the oil phase and adding a curing agent and stirring evenly to obtain a grouting material; as well as Drilling and grouting the grouting material and solidifying it at room temperature to form a breathable hole-protecting material; Among them, the mass ratio of the polymer monomer to the curing agent is 4:(1-2.4); the mass ratio of the oil phase to the polymer monomer is (3.5-5):1; the mass ratio of the polymer monomer to the water phase is (1-4):

1.

2. The preparation method according to claim 1, characterized in that: The polymer monomer includes epoxy resin.

3. The preparation method according to claim 1, characterized in that: The curing agent is a room temperature curing agent, including at least one of a phenolic amine epoxy curing agent, an epoxy resin curing agent or 2,4,6-tris(dimethylaminomethyl)phenol.

4. The preparation method according to claim 1, characterized in that: The oil phase includes at least one of polyethylene glycol, 1,4-dioxane, dimethylformamide, cyclohexanone and dimethyl sulfoxide.

5. The preparation method according to claim 1, characterized in that: The amount of the emulsifier added is not more than 25% of the mass of the polymer monomer; And / or, the emulsifier includes at least one of polyethylene glycol 6000, polysorbate 80, trimethylolpropane glycidyl ether, epoxy resin and boron trifluoride ether complex.

6. The preparation method according to claim 1, characterized in that: The mass ratio of the polymer monomer to the surfactant is less than 100; And / or, the surfactant includes at least one of hexadecyltrimethylammonium bromide, polyvinylpyrrolidone, sodium bis(2-ethylhexyl)succinate sulfonate, and didodecyldimethylammonium bromide.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The parameters of the polymer monomer and the emulsifier being dispersed in the water phase are as follows: the mass of the polymer monomer and the water phase is 10:(3-10).

8. The preparation method according to any one of claims 1 to 6, characterized in that: The grouting material is drilled and grouted and cured at room temperature for 10-15 hours to form a breathable hole-protecting material.

9. A breathable and pore-protecting material suitable for underground coal mine environments, characterized in that: The method is obtained by the preparation method described in any one of claims 1 to 8, comprising a polymer monomer, a curing agent, an oil phase, an aqueous phase, an emulsifier and a surfactant; wherein the mass ratio of the polymer monomer to the curing agent is 4:(1-2.4); the mass ratio of the oil phase to the polymer monomer is (3.5-5):1; the mass ratio of the polymer monomer to the aqueous phase is (1-4):1; the amount of the emulsifier added is not higher than 25% of the mass of the polymer monomer; and the mass ratio of the polymer monomer to the surfactant is less than 100.

10. The breathable pore-protecting material according to claim 9, characterized in that: The breathable pore-protecting material has a connected pore structure and a mechanical pressure bearing strength of ≥2MPa.

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