A breathable hole-protecting material and a preparation method and application thereof

Abstract

The application discloses a kind of breathable hole protection materials, the raw materials of the breathable hole protection material include: polymer monomer, polyethylene glycol, curing agent and perfluorohexanone microcapsule, wherein the polymer monomer includes epoxy resin monomer and hyperbranched epoxy resin, the mass ratio of epoxy resin monomer and hyperbranched epoxy resin is 1:(0.05~1).The breathable hole protection material of the application can effectively improve the crosslinking density of epoxy resin, improve the strength after curing, shorten the curing time at the same time, improve the construction efficiency, heat is not easy to accumulate in the curing process, improve the safety performance, and the hole protection material has excellent air permeability, can be used for hole protection in mine gas extraction.

Description

Technical Field

[0001] This invention belongs to the field of mine gas extraction technology, specifically relating to a breathable hole-protecting material and its preparation method, and more particularly, to an application of the breathable hole-protecting material. Background Technology

[0002] Coal mine gas control primarily involves drilling to extract gas. However, due to the complexity of geological conditions and the dynamic pressure of mining, gas extraction boreholes can deform or even collapse to varying degrees. Current borehole protection technologies mainly employ screen pipe protection combined with cement and polyurethane grouting materials. In long borehole operations, screen pipe protection suffers from drawbacks such as high entry resistance, complex operation, and high construction difficulty. Cement and polyurethane grouting materials, after curing, form a closed structure, blocking the borehole's ventilation channels and significantly reducing gas extraction efficiency. However, the high ratio of pore-forming and expanding agents in permeable borehole protection technologies results in highly plastic materials, making them prone to borehole shrinkage deformation during the protection process. Therefore, it is necessary to conduct in-depth research and improvement on permeable borehole protection materials. Summary of the Invention

[0003] This invention is based on the inventor's discovery and understanding of the following facts and problems: In permeable borehole protection technology, pore-forming agents are required to construct interconnected pore structures. However, these agents dilute the epoxy resin system to a certain extent, leading to prolonged curing time and reduced strength. This results in the high plasticity of the borehole protection material, making it prone to significant permanent deformation under ground stress and surrounding rock pressure during drilling and protection. Long-term use can easily lead to borehole shrinkage, affecting the borehole protection effect. Furthermore, the long curing time can cause the filler to settle under its own weight during curing, resulting in uneven structure and stress concentration, which affects the strength of the material. Simply reducing the proportion of the pore-forming agent can shorten the curing time and improve the strength of the borehole protection, but it will reduce the diameter of the interconnected pores or even form closed pores, seriously affecting the gas extraction efficiency after drilling and protection.

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a breathable borehole protection material that can effectively increase the crosslinking density of epoxy resin, improve the strength after curing, shorten the curing time, improve construction efficiency, prevent heat accumulation during curing, improve safety performance, and possess excellent breathability, making it suitable for borehole protection in mine gas extraction.

[0005] This invention provides a breathable and pore-protecting material. The raw materials of the breathable and pore-protecting material include: polymer monomers, polyethylene glycol, curing agent and perfluorohexanone microcapsules, wherein the polymer monomers include epoxy resin monomers and hyperbranched epoxy resin.

[0006] The advantages and technical effects of the breathable pore-protecting material in this invention are as follows: 1. In this invention, hyperbranched epoxy resin is introduced into the polymer monomer to replace part of the epoxy resin monomer, effectively increasing the crosslinking density of the epoxy resin and improving the strength of the pore-protecting material after curing. Simultaneously, the hyperbranched epoxy resin has more active sites than the epoxy resin monomer, exhibiting higher reactivity, further shortening the curing time and improving the construction efficiency of the pore-protecting material application; 2. In this invention, perfluorohexanone microcapsules are introduced. Since the pore-protecting material releases heat during curing, the perfluorohexanone microcapsules can absorb the heat released during the curing process. The heat released during the curing process causes the perfluorohexanone microcapsules to expand in volume after absorbing heat, leading to the rupture of the capsule shell. The volatilization of perfluorohexanone further carries away the heat from the system, effectively preventing heat accumulation in the borehole. This results in a more stable temperature change during the curing process, reducing the maximum temperature of the curing process. Furthermore, the pores left by the volatilization of perfluorohexanone can further improve the air permeability of the borehole protection material. 3. The borehole protection material of this invention has excellent properties such as high strength, short curing time, and good air permeability. Moreover, the heat during the curing process is not easily accumulated, which can meet the requirements of borehole protection in mine gas extraction.

[0007] In some embodiments, the epoxy equivalent of the epoxy resin monomer is 170-250; preferably, the degree of polymerization n of the epoxy resin monomer is 0.15-0.22; more preferably, the epoxy resin monomer includes at least one of epoxy resin E44, epoxy resin E51, and epoxy resin E54.

[0008] In some embodiments, the hyperbranched epoxy resin includes at least one of hyperbranched polyester epoxy resin, hyperbranched polyether epoxy resin, silicone-modified hyperbranched epoxy resin, or hyperbranched polyamide epoxy resin.

[0009] In some embodiments, the mass ratio of the epoxy resin monomer to the hyperbranched epoxy resin is 1:(0.05-1), preferably 1:(0.05-0.8), and more preferably 1:(0.1-0.5).

[0010] In some embodiments, the polyethylene glycol includes at least one of PEG100, PEG200, PEG300, and PEG400; the mass ratio of the polymer monomer to the polyethylene glycol is 1:(1.3-3), preferably 1:(1.3-2.5), and more preferably 1:(1.4-1.8).

[0011] In some embodiments, the curing agent includes at least one of curing agents T31, 593, and DMP30; the mass ratio of the polymer monomer to the curing agent is 1:(0.3 to 0.5).

[0012] In some embodiments, the shell of the perfluorohexanone microcapsule is a single layer, preferably a polyurea or polyurethane single-layer shell; the mass ratio of the polymer monomer to the perfluorohexanone microcapsule is 1:(0.01-0.2), preferably 1:(0.01-0.16), and more preferably 1:(0.02-0.12).

[0013] In some embodiments, the raw materials of the breathable and pore-protecting material further include a toughening agent. Preferably, the toughening agent includes at least one of polyethylene glycol diglycidyl ether or polypropylene glycol diglycidyl ether. More preferably, the mass ratio of the polymer monomer to the toughening agent is 1:(0.01~0.2).

[0014] This invention also provides a method for preparing a breathable pore-protecting material. Epoxy resin monomers and hyperbranched epoxy resin are added to polyethylene glycol according to a designed ratio, followed by the addition of perfluorohexanone microcapsules. Optionally, a toughening agent is added, and after stirring, a curing agent is added. The mixture is then cured, and after curing, it is immersed in water to remove the oil phase, yielding the breathable pore-protecting material. The preparation method of this invention is simple and easy to operate, and can produce a pore-protecting material with high strength, short curing time, minimal heat accumulation, and good breathability, showing broad application prospects.

[0015] In some embodiments, the curing reaction takes 2-3.5 hours.

[0016] In some embodiments, the maximum temperature during the curing reaction does not exceed 40°C.

[0017] This invention also provides an application of a breathable borehole protection material in borehole protection for coal mine gas drainage. The borehole protection material of this invention features high strength, short curing time, and good air permeability. Furthermore, the material is not prone to heat accumulation, exhibits excellent safety performance, and can meet the requirements for borehole protection in mine gas drainage. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the method for preparing the breathable and pore-protecting material according to an embodiment of the present invention; Figure 2 These are temperature change test curves of Embodiment 1, Comparative Example 1, and Comparative Example 4 of the present invention during the curing process. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] This invention provides a breathable and pore-protecting material. The raw materials of the breathable and pore-protecting material include: polymer monomers, polyethylene glycol, curing agent and perfluorohexanone microcapsules, wherein the polymer monomers include epoxy resin monomers and hyperbranched epoxy resin.

[0021] The breathable pore-protecting material of this invention introduces hyperbranched epoxy resin into the polymer monomer to replace part of the epoxy resin monomer, which effectively increases the crosslinking density of the epoxy resin and improves the strength of the pore-protecting material after curing. At the same time, the hyperbranched epoxy resin has more active sites than the epoxy resin monomer and has higher reactivity, which further shortens the curing time and improves the construction efficiency of the pore-protecting material application.

[0022] In this embodiment of the invention, perfluorohexanone microcapsules are introduced. Since the curing process of the pore-protecting material releases heat, the perfluorohexanone microcapsules can absorb the heat released during the curing process. After absorbing the heat, the perfluorohexanone inside the capsule expands, causing the capsule shell to rupture. The perfluorohexanone volatilizes and further carries away the heat of the system, effectively preventing heat accumulation in the drilling process, making the temperature change during the curing process more stable, reducing the maximum temperature of the curing process, and the pores left by the volatilization of perfluorohexanone can further improve the air permeability of the pore-protecting material.

[0023] The hole protection material of this invention has excellent properties such as high strength, short curing time and good air permeability, and the heat is not easy to accumulate during the curing process, which can meet the requirements of hole protection in mine gas extraction.

[0024] In some embodiments, the epoxy equivalent of the epoxy resin monomer is 170-250; preferably, the degree of polymerization n of the epoxy resin monomer is 0.15-0.22; more preferably, the epoxy resin monomer includes at least one of epoxy resin E44, epoxy resin E51, and epoxy resin E54. In these embodiments, there are no particular limitations on the epoxy resin monomer; any epoxy resin monomer commonly used as a crosslinking host in existing pore-protecting materials is applicable to this application.

[0025] In some embodiments, the hyperbranched epoxy resin includes at least one of hyperbranched polyester epoxy resin, hyperbranched polyether epoxy resin, silicone-modified hyperbranched epoxy resin, or hyperbranched polyamide epoxy resin. Preferably, the mass ratio of the epoxy resin monomer to the hyperbranched epoxy resin is 1:(0.05-1), for example, 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, etc., preferably 1:(0.05-0.8), more preferably 1:(0.1-0.5). In this embodiment of the invention, by controlling the amount of hyperbranched epoxy resin replacing epoxy resin monomers, it is beneficial to further improve the crosslinking density, compensate for the reduction in the strength of the pore-protecting material caused by the dilution of the pore-forming agent polyethylene glycol, and because the hyperbranched epoxy resin has a lower activation energy, the system can trigger the curing reaction at a lower temperature, effectively shortening the curing time, making the curing process more gentle, preventing heat accumulation, and keeping the maximum temperature of the reaction process at a lower temperature, thus improving safety and achieving an effective balance between strength, curing time, and heat accumulation. If the amount of hyperbranched epoxy resin introduced is too small, it cannot fully play its role; if the amount of hyperbranched epoxy resin introduced is too large, it will lead to group aggregation, affecting the strength of the material and thus being detrimental to improving the strength of the epoxy resin. In addition, increasing the amount of hyperbranched epoxy resin added will also affect the phase separation process of epoxy resin in polyethylene glycol, which is not conducive to the air permeability of the cured material. Moreover, hyperbranched epoxy resin is expensive, and excessive addition will increase the cost of using the material, which is not conducive to the large-scale promotion and use of the material in this invention.

[0026] In this embodiment of the invention, the hyperbranched epoxy resin can be purchased directly from the market, with manufacturers such as Wuhan Hyperbranched Resin Technology Co., Ltd.

[0027] In some embodiments, the polyethylene glycol includes at least one of PEG100, PEG200, PEG300, and PEG400. In this embodiment, a preferred type of polyethylene glycol is selected. The epoxy resin monomer has good solubility in the preferred polyethylene glycol. As the curing reaction proceeds, the molecular weight of the epoxy resin gradually increases, and its solubility in the polyethylene glycol begins to decrease. The epoxy resin slowly precipitates and undergoes phase separation with the polyethylene glycol, resulting in a uniform, breathable structure in the pore-protecting material. This further improves the breathability of the pore-protecting material while maintaining good strength.

[0028] In some embodiments, the mass ratio of the polymer monomer to polyethylene glycol is 1:(1.3 to 3), for example 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.0, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, 1:3, etc., preferably 1:(1.3 to 2.5), more preferably 1:(1.4 to 1.8). In this embodiment of the invention, the perfluorohexanone microcapsules, after the shell ruptures, allow the perfluorohexanone to volatilize and form pores in the material, effectively reducing the amount of pore-forming agent polyethylene glycol used. Furthermore, by introducing hyperbranched epoxy resin to replace part of the epoxy resin, the density of the epoxy resin-supported skeleton is increased, thereby improving the strength of the pore-protecting material. This compensates for the strength reduction caused by the dilution of the pore-forming agent polyethylene glycol and effectively prevents drilling shrinkage deformation of the material during the pore-protecting process.

[0029] In some embodiments, the curing agent includes at least one of curing agents T31, 593, and DMP30; the mass ratio of the polymer monomer to the curing agent is 1:(0.3-0.5), for example, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, etc. In these embodiments, there are no particular limitations on the curing agent; commonly used curing agents in the prior art are suitable for this invention.

[0030] In some embodiments, the raw materials of the breathable and pore-protecting material further include a toughening agent. Preferably, the toughening agent includes at least one of polyethylene glycol diglycidyl ether or polypropylene glycol diglycidyl ether. The mass ratio of the polymer monomer to the toughening agent is 1:(0.01~0.2), for example, 1:0.01, 1:0.02, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, 1:0.11, 1:0.12, 1:0.13, 1:0.14, 1:0.15, 1:0.16, 1:0.17, 1:0.18, 1:0.19, 1:0.2, etc. In this embodiment of the invention, a preferred toughening agent is used, which has good dispersibility at room temperature in the polyethylene glycol material system of this embodiment. The introduced toughening agent further improves the impact resistance of the pore-protecting material. While improving the plasticity of the material by separating the epoxy resin phase to form a porous structure, it also achieves an effective balance between the strength of the material.

[0031] In some embodiments, the shell of the perfluorohexanone microcapsule is a single layer, preferably a polyurea or polyurethane single-layer shell; the mass ratio of the polymer monomer to the perfluorohexanone microcapsule is 1:(0.01-0.2), for example 1:0.01, 1:0.02, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, 1:0.11, 1:0.12, 1:0.13, 1:0.14, 1:0.15, 1:0.16, 1:0.17, 1:0.18, 1:0.19, 1:0.2, etc., preferably 1:(0.01-0.16), more preferably 1:(0.02-0.12). In this embodiment of the invention, the optimal amount of perfluorohexanone microcapsules introduced is beneficial for fully absorbing the heat released during the curing process, avoiding heat accumulation in the drilling, and making the temperature change during the curing process more stable. This effectively reduces the maximum temperature during the curing reaction and improves construction safety. Simultaneously, the pores left after the perfluorohexanone volatilizes further improve the air permeability of the pore-protecting material, effectively compensating for the pore reduction caused by reducing the amount of the pore-forming agent polyethylene glycol. If the amount of perfluorohexanone microcapsules introduced is too small, it will not be effective; if the amount introduced is too large, although it can significantly improve the air permeability of the material, it will be detrimental to the improvement of the material strength.

[0032] like Figure 1 As shown in the figure, this invention also provides a method for preparing a breathable pore-protecting material. Epoxy resin monomers and hyperbranched epoxy resin are added to polyethylene glycol according to a designed ratio, followed by the addition of perfluorohexanone microcapsules. Optionally, a toughening agent is added, and after stirring, a curing agent is added. The mixture undergoes a curing reaction, and after curing, it is immersed in water to remove the oil phase, yielding the breathable pore-protecting material. The preparation method of this invention is simple and easy to operate, and can produce a pore-protecting material with high strength, short curing time, minimal heat accumulation, and good breathability, thus having broad application prospects.

[0033] In some embodiments, the curing reaction time is 2-3.5 hours; during the curing reaction, the maximum temperature does not exceed 40°C, preferably 30-38°C. In this embodiment of the invention, by introducing hyperbranched epoxy resin, which has more active sites than ordinary epoxy resin and higher reactivity, the curing time is effectively shortened, compensating for the extended curing time caused by the dilution of the epoxy resin concentration by the porogen polyethylene glycol. Simultaneously, the introduced perfluorohexanone microcapsules can absorb the heat released during the curing process, especially the heat released during the curing reaction of the highly active hyperbranched epoxy resin, preventing heat accumulation inside the borehole, effectively reducing the maximum temperature during the curing process, and improving the safety of the hole-protecting material application.

[0034] This invention also provides an application of a breathable borehole protection material in borehole protection for coal mine gas drainage. The borehole protection material of this invention features high strength, short curing time, and good air permeability. Furthermore, the material is not prone to heat accumulation, exhibits excellent safety performance, and can meet the requirements for borehole protection in mine gas drainage.

[0035] The present invention will now be described in detail with reference to the embodiments.

[0036] All raw materials used in the embodiments of this invention can be obtained through market purchase.

[0037] Example 1 25g of epoxy resin E54 and 5g of hyperbranched polyester epoxy resin were added to 44g of polyethylene glycol PEG200 liquid and stirred evenly. Then, 1g of polyurea single-shell perfluorohexanone microcapsules and 1g of toughening agent polyethylene glycol diglycidyl ether were added and stirred evenly again. Then, 12g of curing agent T31 was added to carry out the curing reaction. After curing, the oil phase was removed by soaking in water to obtain a high-toughness, breathable, and pore-protecting material.

[0038] In this embodiment, the mass ratio of epoxy resin E54 to hyperbranched epoxy resin is 1:0.2, the mass ratio of polymer monomer (i.e., the sum of the masses of epoxy resin E54 and hyperbranched epoxy resin) to polyethylene glycol PEG200 is 1:1.47, the mass ratio of polymer monomer to perfluorohexanone microcapsules is 1:0.03, the mass ratio of polymer monomer to toughening agent polyethylene glycol diglycidyl ether is 1:0.03, and the mass ratio of polymer monomer to curing agent T31 is 2.5:1.

[0039] Example 2 The method is the same as in Example 1, except that the total amount of polymer monomers (i.e., the sum of the mass of epoxy resin E54 and hyperbranched epoxy resin) remains unchanged, and the mass ratio of epoxy resin E54 to hyperbranched epoxy resin is 1:0.5.

[0040] Example 3 The method is the same as in Example 1, except that the total amount of polymer monomers (i.e., the sum of the mass of epoxy resin E54 and hyperbranched epoxy resin) remains unchanged, and the mass ratio of epoxy resin E54 to hyperbranched epoxy resin is 1:0.8.

[0041] Example 4 The method is the same as in Example 1, except that the amount of perfluorohexanone microcapsules is different, and the mass ratio of the polymer monomer to the perfluorohexanone microcapsules is 1:0.08.

[0042] Example 5 The method is the same as in Example 1, except that the amount of perfluorohexanone microcapsules is different, and the mass ratio of the polymer monomer to the perfluorohexanone microcapsules is 1:0.12.

[0043] Example 6 The method is the same as in Example 1, except that the amount of perfluorohexanone microcapsules is different, and the mass ratio of the polymer monomer to the perfluorohexanone microcapsules is 1:0.16.

[0044] Example 7 The method is the same as in Example 1, except that the amount of polyethylene glycol PEG200 is different, and the mass ratio of polymer monomer to polyethylene glycol PEG200 is 1:1.8.

[0045] Example 8 The method is the same as in Example 1, except that the amount of polyethylene glycol PEG200 is different, and the mass ratio of polymer monomer to polyethylene glycol PEG200 is 1:2.0.

[0046] Example 9 The method is the same as in Example 1, except that the hyperbranched epoxy resin used is a hyperbranched polyether type epoxy resin.

[0047] Example 10 The method is the same as in Example 1, except that the hyperbranched epoxy resin used is an organosilicon-modified hyperbranched epoxy resin.

[0048] Example 11 The method is the same as in Example 1, except that the hyperbranched epoxy resin used is hyperbranched polyamide epoxy resin.

[0049] Example 12 The method is the same as in Example 1, except that the toughening agent polyethylene glycol diglycidyl ether is not introduced.

[0050] Comparative Example 1 The method is the same as in Example 1, except that the amount of epoxy resin E54 used is 30g, and hyperbranched epoxy resin and perfluorohexanone microcapsules are not added.

[0051] Comparative Example 2 The method is the same as in Example 1, except that the amount of epoxy resin E54 is 30g, the amount of polyethylene glycol is 54g, and hyperbranched epoxy resin and perfluorohexanone microcapsules are not added, that is, the mass ratio of polymer monomer to polyethylene glycol is 1:1.8.

[0052] Comparative Example 3 The method is the same as in Example 1, except that the amount of epoxy resin E54 used is 30g, and hyperbranched epoxy resin is not added.

[0053] Comparative Example 4 The method is the same as in Example 1, except that perfluorohexanone microcapsules are not introduced.

[0054] Comparative Example 5 The method is the same as in Example 1, except that the amount of polyethylene glycol used is 54g and perfluorohexanone microcapsules are not introduced.

[0055] The performance of the pore-protecting materials prepared in Examples 1-12 and Comparative Examples 1-5 was tested, and the results are shown in Table 1 and 2. Figure 2 .

[0056] 1. Strength test: The protective materials prepared in each embodiment and comparative example were cut into 5cm*5cm*5cm test samples, and the compressive strength was tested using a compressive strength testing machine.

[0057] 2. The method for testing the highest temperature during the reaction process is as follows: Use an infrared thermometer to monitor the reaction temperature in real time during the curing process and record the highest temperature; 3. The water permeability test method is as follows: The slurry formed by mixing the raw materials of each embodiment and comparative example is poured into a cup-shaped mold. The inner diameter of the cup is 48 mm, the wall thickness and bottom thickness are 12 mm, and the height of the cup is 43 mm. After curing, the cup is removed from the mold and soaked in tap water to remove polyethylene glycol. Then, water is added to the cup, and the water permeability is observed. This embodiment of the invention verifies the air permeability performance of the pore-protecting material through a water permeability test.

[0058] Table 1

[0059] Through Table 1 and Figure 2 As can be seen, the borehole protection material of this invention, by introducing hyperbranched epoxy resin to replace part of the epoxy resin monomer and introducing perfluorohexanone microcapsules, effectively improves the strength of the cured borehole protection material and shortens the curing time. During curing, heat is less likely to accumulate, temperature changes are stable, and the maximum temperature during curing is reduced. Simultaneously, the borehole protection material exhibits excellent water permeability. The borehole protection material of this invention can achieve a strength of over 2.5 MPa, a curing time that is generally reduced to below 4 hours, a maximum temperature during the curing reaction that can be controlled below 40°C, and a water permeability that can reach over 20 ml / h, meeting the requirements for borehole protection in mine gas drainage.

[0060] In Comparative Example 1, hyperbranched epoxy resin was not used to replace part of the epoxy resin monomers; all polymer monomers were epoxy resin E54; and perfluorohexanone microcapsules were not introduced. During the curing process, heat continuously accumulated, such as... Figure 2As shown, the temperature rises sharply during the curing reaction, reaching a maximum of 55°C. Simultaneously, insufficient amounts of polyethylene glycol are introduced, resulting in a significant decrease in water permeability to 15 ml / h. In Comparative Example 2, the amount of polyethylene glycol was increased compared to Comparative Example 1, significantly improving the water permeability of the pore-protecting material. However, the strength decreased to 4.2 MPa, and a large amount of heat still accumulates during the curing reaction, reaching a maximum temperature of 50°C.

[0061] In Comparative Example 3, hyperbranched epoxy resin was not used to replace part of the epoxy resin monomers, and all polymer monomers were epoxy resin E54. Compared with Example 1, although the absence of hyperbranched epoxy resin facilitated the phase separation process between epoxy resin E54 and polyethylene glycol, thus improving water permeability, epoxy resin E54 had lower reactivity, higher activation energy, and more intense curing reaction compared to hyperbranched epoxy resin. This resulted in a significant increase in curing time to 4.2 hours, and the highest temperature during the reaction process rose to 42°C. At the same time, the strength of the pore-protecting material decreased after curing.

[0062] In Comparative Example 4, compared to Example 1, no perfluorohexanone microcapsules were introduced. Although the strength after curing was improved and the curing time was shortened, the heat released during the curing reaction continuously accumulated, such as... Figure 2 As shown, the temperature rises rapidly during the curing reaction, reaching a maximum temperature of 48℃, while the water permeability is only 10ml / h. In Comparative Example 5, the amount of polyethylene glycol was increased compared to Comparative Example 4. Although the water permeability was significantly improved compared to Comparative Example 4, the heat accumulation during the curing reaction was severe, with the maximum temperature reaching 55℃.

[0063] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A breathable and pore-protecting material, characterized in that, The raw materials of the breathable and pore-protecting material include: polymer monomers, polyethylene glycol, curing agent and perfluorohexanone microcapsules, wherein the polymer monomers include epoxy resin monomers and hyperbranched epoxy resin.

2. The breathable and pore-protecting material according to claim 1, characterized in that, The epoxy equivalent of the epoxy resin monomer is 170~250; preferably, the degree of polymerization of the epoxy resin monomer is n=0.15~0.22; more preferably, the epoxy resin monomer includes at least one of epoxy resin E44, epoxy resin E51 and epoxy resin E54. And / or, the hyperbranched epoxy resin includes at least one of hyperbranched polyester epoxy resin, hyperbranched polyether epoxy resin, silicone-modified hyperbranched epoxy resin, or hyperbranched polyamide epoxy resin.

3. The breathable and pore-protecting material according to claim 1 or 2, characterized in that, The mass ratio of the epoxy resin monomer to the hyperbranched epoxy resin is 1:(0.05-1), preferably 1:(0.05-0.8), and more preferably 1:(0.1-0.5).

4. The breathable and pore-protecting material according to claim 1, characterized in that, The polyethylene glycol includes at least one of PEG100, PEG200, PEG300, and PEG400; And / or, the mass ratio of the polymer monomer to polyethylene glycol is 1:(1.3-3), preferably 1:(1.3-2.5), more preferably 1:(1.4-1.8).

5. The breathable and pore-protecting material according to claim 1, characterized in that, The curing agent includes at least one of curing agents T31, 593, and DMP30; And / or, the mass ratio of the polymer monomer to the curing agent is 1:(0.3 to 0.5).

6. The breathable and pore-protecting material according to claim 1, characterized in that, The shell of the perfluorohexanone microcapsule is a single layer, preferably a polyurea or polyurethane single-layer shell; And / or, the mass ratio of the polymer monomer to the perfluorohexanone microcapsules is 1:(0.01-0.2), preferably 1:(0.01-0.16), more preferably 1:(0.02-0.12).

7. The breathable and pore-protecting material according to claim 1, characterized in that, The raw materials of the breathable and pore-protecting material also include a toughening agent. Preferably, the toughening agent includes at least one of polyethylene glycol diglycidyl ether or polypropylene glycol diglycidyl ether. More preferably, the mass ratio of the polymer monomer to the toughening agent is 1:(0.01~0.2).

8. A method for preparing the breathable and pore-protecting material according to any one of claims 1-7, characterized in that, Epoxy resin monomers and hyperbranched epoxy resin are added to polyethylene glycol according to the designed ratio, followed by the addition of perfluorohexanone microcapsules. Optionally, a toughening agent is added, and after stirring, a curing agent is added to carry out the curing reaction. After curing, the oil phase is removed by soaking in water to obtain a breathable and pore-protecting material.

9. The method for preparing the breathable and pore-protecting material according to claim 8, characterized in that, The curing reaction takes 2-3.5 hours, and / or the maximum temperature during the curing reaction does not exceed 40°C.

10. The application of the permeable borehole protection material according to any one of claims 1-7 or the permeable borehole protection material prepared by the method according to any one of claims 8-9 in the borehole protection of coal mine gas drainage drilling.

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