Intumescent pressure-resistant material, method for producing same and use thereof

Abstract

The application provides an intumescent compression-resistant material and a preparation method and application thereof, which comprises a porous structure formed by curing of a thermosetting resin and water sealed in the porous structure; the pore size of the porous structure is 60-400 mu m, and the porosity of the intumescent compression-resistant material is 8-30%; the intumescent compression-resistant material has a first weight loss peak within 100-300 DEG C, a second weight loss peak within 320-380 DEG C and a third weight loss peak within 400-500 DEG C as measured by DSC; the weight loss rate of the intumescent compression-resistant material at the first weight loss peak is less than 4%, the weight loss rate at the second weight loss peak is 4-20%, and the weight loss rate at the third weight loss peak is 21-55%. The thermosetting resin in the intumescent compression-resistant material of the application forms a porous structure, the porous structure seals water in the intumescent compression-resistant material, and by controlling the pore size of the porous structure and the porosity of the intumescent compression-resistant material, the intumescent compression-resistant material with rigidity and flexibility is formed; at a well bottom high temperature of 100 DEG C or above, the functional water sealed by curing reaches the boiling point and boils, and the volume expands.

Description

Technical Field

[0001] This invention relates to the field of oil drilling engineering technology, specifically to expandable pressure-resistant materials, their preparation methods, and applications. Background Technology

[0002] Intumescent pressure-resistant materials are special materials used in oil drilling to seal formation leakage and improve wellbore stability. With continuous technological advancements, intumescent pressure-resistant materials are constantly evolving, mainly including water-absorbing and oil-absorbing expansion materials. Water-absorbing or oil-absorbing expansion plugging materials have high elasticity and expansion capacity, achieving an 8-9 times volume expansion effect. Thermoplastic polyurethane materials can achieve 3-30 times volume expansion. However, the high expansion rate leads to a drawback: the molecular structure becomes loose after expansion, resulting in a significant decrease in compressive strength, generally less than 1.0 MPa. The pressure-bearing capacity can only be improved by combining them with rigid materials through stacking and compression. Furthermore, the temperature resistance of these materials is only around 150℃-180℃, making them unsuitable for use in ultra-high temperature, high-pressure deep wells with leakage.

[0003] Thermosetting shape memory polymer (EMP) plugging materials possess high-temperature resistance and strong mechanical properties, making them crucial for plugging complex lost circulation formations in oil drilling, particularly in deep and ultra-deep wells. This has garnered significant attention from plugging researchers. Currently, the expansion function of EMP plugging materials is achieved through foaming and filling techniques: hollow glass microspheres, hollow glass microspheres, or gas-generating materials are added during the curing reaction. The cured polymer is then pressurized into sheets at approximately the activation temperature, cooled, and granulated. Upon reaching the activation temperature downhole, expansion occurs, transforming the sheet shape into a spherical form. Therefore, this technology achieves linear expansion, not volumetric expansion. Furthermore, the expansion rate is relatively low, typically between 50% and 80%. While adding large amounts of hollow materials can achieve 1-3 times linear expansion, it reduces the original compressive strength of the cured body, with the pressure resistance after high-temperature expansion generally not exceeding 5 MPa. Therefore, there is still a significant trend of decreased compressive strength after expansion, which is detrimental to constructing a stable high-temperature plugging layer. Furthermore, because the hot pressing process is relatively complex, it is currently in the pilot stage, which limits the industrialization and large-scale application of this technology.

[0004] Chinese patent CN113652212B discloses "Shape Memory Type Leakage Prevention and Plugging System, Preparation Method and Application Thereof," which belongs to the field of oil and gas well leakage plugging, specifically involving a thermo-induced shape memory type intelligent leakage prevention and plugging system, its preparation method and application. The shape memory plugging agent composition contains epoxy resin, amine curing agent, reactive diluent and foaming agent; wherein the weight ratio of epoxy resin, amine curing agent, reactive diluent and foaming agent is 100:5-30:1-20:40-70. Based on shape memory materials, the intelligent leakage plugging system allows the plugging fluid to identify the leakage layer temperature, and achieves shape change through the shape recovery of the shape memory plugging agent. This develops a thermo-induced shape memory type intelligent leakage prevention and plugging material, forming an intelligent leakage prevention and plugging technology. The shape memory polymer has a response temperature range of 80℃~105℃. The obtained polymer is thermomechanically compressed, then pulverized and granulated to produce expandable particles LC5 with a particle size of 1mm~2mm and an expansion rate of 120%.

[0005] The shape memory leak-proof and sealing systems described in the aforementioned patent documents have low expansion and are only suitable for low-temperature leak sealing within a temperature range of 80℃ to 105℃, making them unsuitable for high-temperature leak sealing. Therefore, there is an urgent need to develop an expansion-type leak-proof material with stable mechanical properties at high temperatures to address multi-scale crack-related severe leakage or narrow-density window leakage, thereby improving the success rate of sealing complex leaks. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem of low expansion of thermosetting shape memory materials in the prior art, and to provide an expandable compressive strength material, its preparation method and application. This expandable compressive strength material achieves a high proportion of volume expansion of thermosetting resin materials while improving the overall mechanical strength of the material.

[0007] To achieve the above objectives, the first aspect of the present invention provides an intumescent compressive-resistant material comprising a porous structure formed by curing a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 60 μm to 400 μm, and the porosity of the intumescent compressive-resistant material is 8 to 30%.

[0008] DSC measurements show that the expansion and compressive strength material has a first weight loss peak in the range of 100℃ to 300℃, a second weight loss peak in the range of 320℃ to 380℃, and a third weight loss peak in the range of 400℃ to 500℃. The weight loss rate of the expansion and compressive strength material at the first weight loss peak is <4%, the weight loss rate at the second weight loss peak is 4% to 20%, and the weight loss rate at the third weight loss peak is 21% to 55%.

[0009] It is believed that the relatively flat first weight loss peak at 100℃ to 300℃ may be obtained by the evaporation of water adsorbed on the surface of the expansion and compression resistant material; the second weight loss peak at 320℃ to 380℃ may be obtained by the rapid evaporation of water sealed in the material after the structure of the expansion and compression resistant material is destroyed by high temperature heating; and the third weight loss peak above 400℃ may be obtained by the decomposition and vaporization of the non-aqueous components of the expansion and compression resistant material.

[0010] The thermosetting resin in the intumescent pressure-resistant material of this invention is cured to form a porous structure. This porous structure seals water within the intumescent pressure-resistant material. By controlling the pore size of the porous structure and the porosity of the intumescent pressure-resistant material, an intumescent pressure-resistant material that combines rigidity and flexibility is formed. As the temperature rises, especially in environments with high temperatures of 100°C and above at the bottom of wells, the water sealed within the intumescent pressure-resistant material vaporizes, particularly rapidly upon reaching its boiling point, causing volume expansion. The higher the temperature, the greater the expansion.

[0011] In some embodiments of the present invention, the thermosetting resin comprises one or more of epoxy resin, phenolic resin, polyetherketone resin, and polyimide resin.

[0012] In some embodiments of the present invention, the pore size of the porous structure is 100 μm to 320 μm, and the porosity of the expansion and compressive strength material is 10 to 25%.

[0013] A second aspect of the present invention provides a method for preparing an expansion-resistant compressive material, comprising the following steps:

[0014] Preparation of the first mixture S1: The thermosetting resin is mixed with the first curing agent to obtain the first mixture;

[0015] Preparation of the second mixture S2: Mix the second curing agent with water to obtain the second mixture;

[0016] Preparation of the third mixture S3: Mix the first mixture and the second mixture evenly, add the accelerator and foaming agent, and stir for ≥10 minutes at 60℃~85℃ with the speed adjusted to 700rpm~3000rpm to obtain the third mixture;

[0017] S4 Curing: Curing the third mixture to obtain the expansion and compression resistant material.

[0018] In step S1, the thermosetting resin undergoes a crosslinking reaction with the first curing agent to obtain a pre-crosslinked body. In step S3, the second curing agent is added to the pre-crosslinked body, mixed evenly, and then an accelerator and a foaming agent are added before curing. Adding the first and second curing agents in steps, with the thermosetting resin and the first curing agent forming the pre-crosslinked body first, allows for easier control of the crosslinking reaction rate and direction compared to adding both simultaneously. Furthermore, the resulting pre-crosslinked body and the second curing agent are more evenly distributed, resulting in a high-temperature mechanical strength and strong sealing ability for functional water in the prepared intumescent and pressure-resistant material.

[0019] In the preparation process of the intumescent and pressure-resistant material of the present invention, a steam-driven process is used to seal functional water in the first mixture prepared in step S1 and then cure it. When the temperature rises to 100°C or above, the functional water sealed in the material boils due to reaching its boiling point, and its volume expands. The higher the temperature, the greater the expansion energy, and the greater the expansion amount. This preparation method simplifies the process of thermosetting shape memory resins, which must first be hot-pressed to achieve expansion, changing the linear expansion of the resin to a high-proportion volumetric expansion, with an expansion rate as high as 660%, significantly enhancing its adaptability to filling and sealing spaces.

[0020] In some embodiments of the present invention, in step S1, the thermosetting resin is heated to 60°C to 85°C, the first curing agent is added, the temperature is adjusted to 5°C to 30°C above the melting point of the first curing agent, and after the first curing agent is completely dissolved, it is stirred at a stirring speed of 200 to 400 rpm for 20 to 60 minutes, and then adjusted to 60°C to 85°C to obtain the first mixture.

[0021] In some embodiments of the present invention, step S2 includes step S2-1, step S2-2 or step S2-3;

[0022] Step S2-1: The second curing agent is a solid with a melting point ≥90℃. Add the second curing agent to the solution and adjust the temperature to 5℃~30℃ above the melting point of the second curing agent. After the second curing agent is completely dissolved, adjust the temperature to 60℃~85℃, add water, and stir at a stirring speed of 200~400rpm for 20~60min to obtain the second mixture.

[0023] Step S2-2: The second curing agent is a solid with a melting point <90℃. Add the second curing agent to water and heat it to 5℃~10℃ above the melting point of the second curing agent. After the second curing agent is completely dissolved, adjust the temperature to 60℃~85℃ and stir at a stirring speed of 200~400rpm for 20~60min to obtain the second mixture.

[0024] Step S2-3: The second curing agent is a liquid. Adjust the temperature to 60℃~85℃, add water to the second curing agent, and stir at a stirring speed of 200~400rpm for 20~60min to obtain the second mixture.

[0025] In some embodiments of the present invention, in step S3, the second mixture is added to the first mixture, an accelerator and a foaming agent are added, and the mixture is stirred for 10-30 minutes to obtain a third mixture.

[0026] In some embodiments of the present invention, in step S4, the curing includes two or all three of the following: first curing, second curing, and third curing; the first curing is carried out at a constant temperature of 100℃~110℃ for 2h~8h; the second curing is carried out at a constant temperature of 120℃~130℃ for 0.5h~4h; and the third curing is carried out at a constant temperature of 140℃~160℃ for 0.5h~4h.

[0027] In some embodiments of the present invention, the first curing agent and the second curing agent may be the same or different, and each is independently selected from one or more of acid anhydride curing agents, phenolic curing agents, and aromatic polyamine curing agents.

[0028] In some embodiments of the present invention, the mass ratio of the first curing agent to the second curing agent is (0.75-3):1.

[0029] In some embodiments of the present invention, based on 100 parts by weight of thermosetting resin, the total amount of the first curing agent and the second curing agent is 50 to 100 parts by weight, the amount of accelerator is 0 to 2 parts by weight, the amount of water is 10 to 50 parts by weight, and the amount of foaming agent is 0.1 to 3 parts by weight.

[0030] This invention obtains an expansion-resistant and pressure-resistant material with high expansion rate and high mechanical strength under high temperature environment by further adjusting the amounts of the thermosetting resin, the first curing agent and the second curing agent, the accelerator, water and the foaming agent.

[0031] In some embodiments of the present invention, the accelerator comprises one or more of triethanolamine, dimethylaniline, and 2,4,6-tris(dimethylaminomethyl)phenol.

[0032] In some embodiments of the present invention, the water is fresh water or salt water, and preferably, a foam enhancer is added to the water.

[0033] In some embodiments of the present invention, the foaming agent comprises one or more of anionic foaming agents, cationic foaming agents, and nonionic foaming agents.

[0034] In some embodiments of the present invention, the amount of the solution used is 10 to 20 parts by weight.

[0035] In some embodiments of the present invention, the solution contains at least one of a liquid resin curing agent and a liquid resin toughening agent.

[0036] In some embodiments of the present invention, the solution comprises at least one of a modified aromatic amine liquid curing agent, a modified phenolic curing agent, and an alkenyl succinic anhydride.

[0037] In some embodiments of the present invention, the epoxy resin comprises one or more of glycidyl ether epoxy resin, glycidyl amine epoxy resin, glycidyl ester epoxy resin, imide-modified epoxy resin, and phenolic-modified epoxy resin.

[0038] In some embodiments of the present invention, the epoxy resin comprises one or more of bisphenol A diglycidyl ether, phenolic epoxy resin, and imide epoxy resin.

[0039] In some embodiments of the present invention, the epoxy resin comprises one or both of bisphenol A diglycidyl ether E51 and phenolic epoxy resin F51.

[0040] In some embodiments of the present invention, the anhydride curing agent comprises one or more of maleic anhydride, alkenyl succinic anhydride (ASA), phthalic anhydride (PA), cyclopentetrate dianhydride (CPTA), and methyl hexahydrophthalic anhydride (MHHPA).

[0041] In some embodiments of the present invention, the curing agent comprises one or two of the following: modified phenolic high-temperature curing agent F-52B or F-51A, and modified aromatic amine liquid curing agent VT5327.

[0042] In some embodiments of the present invention, the foam enhancer comprises one or more of surfactant enhancers, drilling fluid surface viscosity enhancers, or surface shear strength enhancers.

[0043] In some embodiments of the present invention, the foam enhancer comprises one or both of a surfactant or a thickening and cutting agent.

[0044] In some embodiments of the present invention, the surfactant-based foam enhancer comprises one or more of polysorbate, sorbitan monooleate, oleyl alcohol polyoxyethylene ether, and dodecyl oleate.

[0045] In some embodiments of the present invention, the thickening and cutting agent-type foam reinforcing agent comprises one or more of hydroxyethyl methyl cellulose, polyacrylamide, and sodium carboxymethyl starch.

[0046] In some embodiments of the present invention, the foam enhancer content is 0.1% to 1% by weight of the water.

[0047] In some embodiments of the present invention, the anionic foaming agent is selected from one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium fatty acid methyl ester ethoxylate sulfonate, fatty alcohol glyceryl ether sulfonate, or α-olefin sulfonate.

[0048] In some embodiments of the present invention, the anionic foaming agent is selected from one or more of sodium dodecylbenzenesulfonate, fatty alcohol glyceryl ether sulfonate, or α-olefin sulfonate.

[0049] In some embodiments of the present invention, the cationic foaming agent is selected from one or more of hexadecyltrimethylammonium bromide, fatty ether triethanolamine salt, and alkylbenzene sulfonic acid triethanolamine salt.

[0050] In some embodiments of the present invention, the nonionic foaming agent is selected from one or more of coconut oil diethanolamide, cocamidopropyl dimethyl tertiary amine and oleamide propyl dimethyl tertiary amine.

[0051] A third aspect of the present invention provides an intumescent pressure-resistant sealing agent, wherein the sealing agent comprises the above-mentioned intumescent pressure-resistant material or the intumescent pressure-resistant material prepared by the above-mentioned preparation method.

[0052] The technical solution provided by this invention has the following beneficial effects:

[0053] 1. In the expandable pressure-resistant material of the present invention, the thermosetting resin is cured to form a porous structure. This porous structure seals water within the expandable pressure-resistant material. By controlling the pore size of the porous structure and the porosity of the expandable pressure-resistant material, an expandable pressure-resistant material with both rigidity and flexibility is formed. As the temperature rises, especially in environments with high temperatures of 100°C and above at the bottom of wells, the water sealed within the expandable pressure-resistant material vaporizes, particularly rapidly upon reaching its boiling point, causing volume expansion. The higher the temperature, the greater the expansion.

[0054] 2. The preparation method of the expansion and compression-resistant material of the present invention realizes a high proportion of volumetric expansion of thermosetting resin, thus enhancing its self-adaptive ability. Furthermore, the preparation method simplifies the process that thermosetting shape memory resin must first be hot-pressed to achieve expansion, changing the linear expansion of the resin to a high proportion of volumetric expansion, with an expansion rate of up to 660%, thereby enhancing its adaptability to filling and sealing spaces.

[0055] 3. The preparation method of the expandable compressive strength material of the present invention overcomes the defects of previous materials, such as loose structure and decreased mechanical properties after expansion; it enables the material to retain high compressive and shear strength under vapor pressure after expansion at high temperature. The compressive strength at room temperature reaches 82.6 MPa, and the tensile strength reaches 49.2 MPa. The mechanical properties after high-temperature steam expansion at 180℃ are superior to those of the solidified bulk material at high temperature, with a compressive strength retention rate of 23% or more at 180℃ and a tensile strength retention rate of 15% or more at 180℃. Detailed Implementation

[0056] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Unless otherwise specified, specific conditions in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the materials used in the embodiments are commercially available products or conventional products that can be synthesized by known methods.

[0057] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0058] The main reagents used in this invention are as follows:

[0059] Bisphenol A diglycidyl ether E51 was purchased from Hubei Dongcao Chemical Technology Co., Ltd., CAS No. 1675-54-3.

[0060] The phenolic epoxy resin F51 was purchased from Nantong Xingchen Synthetic Materials Co., Ltd.

[0061] Maleic anhydride was purchased from Sinopharm Group, CAS number 108-31-6.

[0062] The alkenyl succinic anhydride (ASA) was purchased from Guangzhou Haoyi New Material Technology Co., Ltd., CAS No. 26544-38-7.

[0063] Phthalic anhydride (PA) was purchased from Shandong Sanju Chemical Technology Co., Ltd., CAS No. 85-44-9.

[0064] The modified phenolic high-temperature curing agent F-52B was purchased from Bengbu Tianyu High-Temperature Resin Materials Co., Ltd.

[0065] The modified aromatic amine liquid curing agent VT5327 was purchased from Shenzhen Huite Chemical Co., Ltd.

[0066] VT5327 is a liquid modified aromatic amine curing agent, a yellow to brown viscous liquid, mainly used as a high-temperature curing agent for epoxy resins.

[0067] Hydroxyethyl methylcellulose was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., CAS No. 9032-42-2.

[0068] Sodium dodecylbenzenesulfonate (SDBS) was purchased from Shandong Yongwang Chemical Co., Ltd., CAS No. 25155-30-0.

[0069] Sodium α-olefin sulfonate (AOS) was purchased from China National Light Industry Chemical Co., Ltd., CAS No. 68439-57-6.

[0070] The testing method used in this invention:

[0071] 1. Test methods for pore size and porosity

[0072] The expansion and compressive strength materials prepared in the examples and comparative examples were made into test samples according to a mold with specifications of 60mm×60mm×30mm. The samples were subjected to liquid nitrogen brittle fracture, and the surface morphology of the samples was observed using a Hitachi S4800 field emission scanning electron microscope to obtain their pore size and porosity.

[0073] 2. Test method for weightlessness rate

[0074] The mass of the expansion and compressive strength material prepared in the test examples and comparative examples is recorded as m1. The expansion and compressive strength material is heated to 100-300℃ at a rate of 5℃ / min, maintained at the high temperature for 4-5 hours, removed and cooled to room temperature, and its mass is recorded as m2. The first weight loss rate is calculated according to the formula: First weight loss rate = 100(m1-m2) / m1. The expansion and compressive strength material is heated to 320-380℃ at a rate of 5℃ / min, maintained at the high temperature for 4-5 hours, removed and cooled to room temperature, and its mass is recorded as m3. The second weight loss rate is calculated according to the formula: Second weight loss rate = 100(m2-m3) / m2. The expansion and compressive strength material is heated to 400-500℃ at a rate of 5℃ / min, maintained at the high temperature for 3-4 hours, removed and cooled to room temperature, and its mass is recorded as m4. The third weight loss rate is calculated according to the formula: Third weight loss rate = 100(m4-m3) / m3.

[0075] Example 1

[0076] Example 1 provides a method for preparing an expansion-resistant compressive material.

[0077] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 60℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 35g of maleic anhydride while stirring at 300rpm. Adjust the temperature to 85℃ and continue stirring for 40min after the maleic anhydride dissolves. Adjust the temperature to 60℃ to obtain the first mixture.

[0078] Preparation of the second mixture S2: Add 25g of maleic anhydride to 20mL of water, adjust the temperature to 85℃, maintain a stirring speed of 200rpm until the maleic anhydride is completely dissolved, adjust the temperature to 60℃, and obtain the second mixture;

[0079] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix evenly, then add 1g of dimethylaniline and 0.12g of sodium dodecylbenzenesulfonate. Stir at 60℃ for 10 minutes at a speed of 2000rpm to obtain the third mixture.

[0080] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 2 hours, then raise the temperature to 150℃ and keep it at 1 hour to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compression resistant material.

[0081] The intumescent compressive strength material prepared in Example 1 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 120–150 μm, and the porosity of the intumescent compressive strength material is 11.56%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 0.4%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 8.7%; above 400 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 35.2%.

[0082] Example 2

[0083] Example 2 provides a method for preparing an expansion-resistant compressive material.

[0084] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 60℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 40g of maleic anhydride while stirring at 300rpm. Adjust the temperature to 85℃ and continue stirring for 40min after the maleic anhydride dissolves. Adjust the temperature to 60℃ to obtain the first mixture.

[0085] Preparation of the second mixture S2: Add 36g of maleic anhydride to 20mL of water, adjust the temperature to 85℃, maintain a stirring speed of 200rpm until the maleic anhydride is completely dissolved, adjust the temperature to 60℃, and obtain the second mixture;

[0086] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix evenly, then add 1.2g of dimethylaniline and 0.12g of sodium dodecylbenzenesulfonate. Stir at 60℃ for 10 minutes at a speed of 2000rpm to obtain the third mixture.

[0087] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 4 hours to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compressive strength material.

[0088] The intumescent compressive strength material prepared in Example 2 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 120–150 μm, and the porosity of the intumescent compressive strength material is 10.53%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 0.5%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 7.0%; above 400 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 33.4%.

[0089] Example 3

[0090] Example 3 provides a method for preparing an expansion-resistant compressive material.

[0091] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 60℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 40g of maleic anhydride while stirring at 300rpm. Adjust the temperature to 85℃ and continue stirring for 40min after the maleic anhydride dissolves. Adjust the temperature to 60℃ to obtain the first mixture.

[0092] Preparation of the second mixture S2: Add 36g of maleic anhydride to 30mL of water, adjust the temperature to 85℃, maintain a stirring speed of 200rpm until the maleic anhydride is completely dissolved, adjust the temperature to 60℃, and obtain the second mixture;

[0093] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix evenly, then add 1.2g of dimethylaniline and 0.12g of sodium dodecylbenzenesulfonate. Stir at 60℃ for 10 minutes at a speed of 2000rpm to obtain the third mixture.

[0094] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 4 hours to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compressive strength material.

[0095] The intumescent compressive strength material prepared in Example 3 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 160–200 μm, and the porosity of the intumescent compressive strength material is 15.61%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.1%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 12.7%; above 420 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 43.6%.

[0096] Example 4

[0097] Example 4 provides a method for preparing an expansion-resistant compressive material.

[0098] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 60℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 25g of maleic anhydride while stirring at 300rpm. Adjust the temperature to 85℃. After the maleic anhydride dissolves, add 15g of alkenyl succinic anhydride. Continue stirring for 40min and adjust the temperature to 60℃ to obtain the first mixture.

[0099] Preparation of the second mixture S2: Add 20g of maleic anhydride to 30mL of water, adjust the temperature to 85℃, and keep stirring at 200rpm until the maleic anhydride is completely dissolved. Then add 16g of alkenyl succinic anhydride and adjust the temperature to 60℃ to obtain the second mixture.

[0100] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix well, then add 1.2g of dimethylaniline and 0.25g of sodium dodecylbenzenesulfonate. Stir at 60℃ for 10 minutes at 1000 rpm to obtain the third mixture.

[0101] S4 Curing: Brush silicone oil onto the mold surface, put the third mixture into the mold, place the mold in a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 4 hours, then raise the temperature to 150℃ and keep it at 1 hour to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compression resistant material.

[0102] The intumescent compressive strength material prepared in Example 4 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 250–300 μm, and the porosity of the intumescent compressive strength material is 15.5%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.9%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 10.1%; above 420 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 38.5%.

[0103] Example 5

[0104] Example 5 provides a method for preparing an expansion-resistant compressive material.

[0105] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 60℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 25g of maleic anhydride while stirring at 300rpm. Adjust the temperature to 85℃. After the maleic anhydride dissolves, add 15g of alkenyl succinic anhydride. Continue stirring for 40min and adjust the temperature to 60℃ to obtain the first mixture.

[0106] Preparation of the second mixture S2: Add 20g of maleic anhydride to 40mL of water, adjust the temperature to 85℃, and keep stirring at 200rpm until the maleic anhydride is completely dissolved. Then add 16g of alkenyl succinic anhydride and adjust the temperature to 60℃ to obtain the second mixture.

[0107] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix well, then add 1.2g of dimethylaniline and 0.25g of sodium dodecylbenzenesulfonate. Stir at 60℃ for 10 minutes at 1000 rpm to obtain the third mixture.

[0108] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 2 hours, then raise the temperature to 150℃ and keep it at 2 hours to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compression resistant material.

[0109] The intumescent compressive strength material prepared in Example 5 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 250–300 μm, and the porosity of the intumescent compressive strength material is 20.1%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.7%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 15.0%; above 450 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 50.2%.

[0110] Example 6

[0111] Example 6 provides a method for preparing an expansion-resistant compressive material.

[0112] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 60℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 25g of maleic anhydride while stirring at 300rpm. Adjust the temperature to 85℃. After the maleic anhydride dissolves, add 15g of alkenyl succinic anhydride. Continue stirring for 40min and adjust the temperature to 60℃ to obtain the first mixture.

[0113] Preparation of the second mixture S2: Add 0.3g of hydroxyethyl methylcellulose to 40mL of water, stir until completely dissolved, adjust the temperature to 85℃, add 20g of maleic anhydride, keep stirring at 200rpm until the maleic anhydride is completely dissolved, add 16g of alkenyl succinic anhydride, adjust the temperature to 60℃, and obtain the second mixture.

[0114] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix evenly, then add 1.2g of dimethylaniline and 0.50g of sodium α-olefin sulfonate. Stir at 60℃ for 10 minutes at 1000 rpm to obtain the third mixture.

[0115] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 2 hours, then raise the temperature to 150℃ and keep it at 2 hours to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compression resistant material.

[0116] The intumescent compressive strength material of Example 6 comprises a porous structure formed by the curing of thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 230–280 μm, and the porosity of the intumescent compressive strength material is 20.22%; using DSC measurement, at 200–270°C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.6%; at 360–370°C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 15.3%; above 450°C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 51.3%.

[0117] Example 7

[0118] Example 7 provides a method for preparing an expansion-resistant compressive material.

[0119] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 60℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 40g of alkenyl succinic anhydride while stirring at 300rpm. Adjust the temperature to 85℃ and continue stirring for 40min. Adjust the temperature to 60℃ to obtain the first mixture.

[0120] Preparation of the second mixture S2: Add 20g of maleic anhydride to 40mL of water, adjust the temperature to 85℃, and keep stirring at 200rpm until the maleic anhydride is completely dissolved. Then add 16g of alkenyl succinic anhydride and adjust the temperature to 60℃ to obtain the second mixture.

[0121] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix evenly, then add 1.2g of dimethylaniline and 0.50g of sodium α-olefin sulfonate. Stir at 60℃ for 10 minutes at a speed of 2000rpm to obtain the third mixture.

[0122] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 2 hours, then raise the temperature to 150℃ and keep it at 2 hours to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compression resistant material.

[0123] The intumescent compressive strength material prepared in Example 7 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 160–200 μm, and the porosity of the intumescent compressive strength material is 20.28%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.5%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 16.5%; above 450 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 54.8%.

[0124] Example 8

[0125] Example 8 provides a method for preparing an expansion-resistant compressive material.

[0126] Preparation of the first mixture S1: Heat 60g of bisphenol A diglycidyl ether E51 to 60℃ and add 40g of phenolic epoxy resin F51. After maintaining the temperature for 10min, wait until the bisphenol A diglycidyl ether E51 and phenolic epoxy resin F51 become thin. Then, while stirring at 300rpm, add 25g of alkenyl succinic anhydride and 15g of modified phenolic high-temperature curing agent F-52B. Adjust the temperature to 85℃ and continue stirring for 40min. Adjust the temperature to 60℃ to obtain the first mixture.

[0127] Preparation of the second mixture S2: Mix 20g of alkenyl succinic anhydride and 16g of modified phenolic high-temperature curing agent F-52B evenly, adjust the temperature to 85℃, maintain a stirring speed of 200rpm, add 30mL of water while stirring, and adjust the temperature to 60℃ to obtain the second mixture.

[0128] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix well, then add 1.2g of 2,4,6-tris(dimethylaminomethyl)phenol and 0.25g of sodium dodecylbenzenesulfonate. Stir at 60℃ for 10 minutes at 1000 rpm to obtain the third mixture.

[0129] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 100℃ for 4 hours, then raise the temperature to 120℃ and keep it at 2 hours, then raise the temperature to 150℃ and keep it at 1 hour to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compression resistant material.

[0130] The intumescent compressive strength material prepared in Example 8 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 230–280 μm, and the porosity of the intumescent compressive strength material is 15.48%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.7%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 12.8%; above 420 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 46.8%.

[0131] Example 9

[0132] Example 9 provides a method for preparing an expansion-resistant compressive material.

[0133] Preparation of the first mixture S1: Heat 100g of bisphenol A diglycidyl ether E51 to 85℃ and maintain the temperature for 10min. After the bisphenol A diglycidyl ether E51 becomes thin, add 25g of phthalic anhydride PA while stirring at 300rpm. Adjust the temperature to 135℃ and add 15g of modified aromatic amine liquid curing agent VT5327. After the phthalic anhydride PA is completely dissolved, continue stirring for 20min and adjust the temperature to 85℃ to obtain the first mixture.

[0134] Preparation of the second mixture S2: Add 20g of phthalic anhydride PA to 16g of modified aromatic amine liquid curing agent VT5327, adjust the temperature to 135℃, maintain a stirring speed of 200rpm until the phthalic anhydride PA is completely dissolved, adjust the temperature to 85℃, and then add 40mL of water while stirring to obtain the second mixture.

[0135] Preparation of the third mixture S3: Add the second mixture to the first mixture, mix well, then add 1.2g of 2,4,6-tris(dimethylaminomethyl)phenol and 0.50g of sodium α-olefin sulfonate. Stir at 85℃ for 10 minutes at 1000 rpm to obtain the third mixture.

[0136] S4 Curing: Brush silicone oil on the mold surface, put the third mixture into the mold, put the mold into a preheated constant temperature box, keep it at 120℃ for 4 hours, then raise the temperature to 150℃ and keep it at 4 hours to complete the curing; after the cured body cools down, the cured body board is obtained, and after demolding, it is crushed into different particle sizes to obtain the expansion and compressive strength material.

[0137] The intumescent compressive strength material prepared in Example 9 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 230–280 μm, and the porosity of the intumescent compressive strength material is 20.18%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.3%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 14.9%; above 400 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 39.0%.

[0138] Example 10

[0139] The expansion and compression-resistant material was prepared according to the method described in Example 6, except that maleic anhydride and alkenyl succinic anhydride were added at once instead of in steps; the material was kept at 100°C for 24 hours, then heated to 120°C for 4 hours, and then heated to 150°C for 2 hours to complete the curing.

[0140] The intumescent compressive strength material prepared in Example 10 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 260–300 μm, and the porosity of the intumescent compressive strength material is 20.31%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 1.9%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 16.2%; above 400 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 43.8%.

[0141] Comparative Example 1

[0142] The expansion-resistant material was prepared according to the method described in Example 6, except that 1.2g of dimethylaniline was not added; the material was kept at 100°C for 120h, and then heated to 120°C and kept at 120°C for 4h to complete the curing.

[0143] The intumescent compressive-resistant material prepared in Comparative Example 1 comprises a porous structure formed by the curing of thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 320–370 μm, and the porosity of the intumescent compressive-resistant material is 20.14%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive-resistant material at the first weight loss peak is 4.5%; at 360–370 °C, the weight loss rate of the intumescent compressive-resistant material at the second weight loss peak is 13.8%; above 450 °C, the weight loss rate of the intumescent compressive-resistant material at the third weight loss peak is 53.5%.

[0144] Comparative Example 2

[0145] The expansion-resistant material was prepared according to the method described in Example 6, except that 40 mL of water was not added; and it was cured at a constant temperature of 150°C for 1 hour.

[0146] The intumescent compressive-resistant material prepared in Comparative Example 2 comprises a porous structure formed by the curing of thermosetting resin; the pore size of the porous structure is 100–180 μm, and the porosity of the intumescent compressive-resistant material is 5.06%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive-resistant material at the first weight loss peak is 0%; at 360–370 °C, the weight loss rate of the intumescent compressive-resistant material at the second weight loss peak is 0%; above 450 °C, the weight loss rate of the intumescent compressive-resistant material at the third weight loss peak is 40.2%.

[0147] Comparative Example 3

[0148] The expansion-resistant material was prepared according to the method described in Example 6, except that 0.50 g of sodium α-olefin sulfonate was not added.

[0149] The intumescent compressive-resistant material prepared in Comparative Example 3 comprises a porous structure formed by the curing of thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 30–50 μm, and the porosity of the intumescent compressive-resistant material is 7%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive-resistant material at the first weight loss peak is 1.8%; at 360–370 °C, the weight loss rate of the intumescent compressive-resistant material at the second weight loss peak is 6%; above 450 °C, the weight loss rate of the intumescent compressive-resistant material at the third weight loss peak is 36.8%.

[0150] Comparative Example 4

[0151] The expansion and compression-resistant material was prepared according to the method described in Example 6, except that: in the preparation of the third mixture S3, 0.25g of sodium dodecylbenzenesulfonate was added, the speed was adjusted to 500rpm, and the mixture was stirred for 8min.

[0152] The intumescent compressive strength material prepared in Comparative Example 5 comprises a porous structure formed by the curing of a thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 700–800 μm, and the porosity of the intumescent compressive strength material is 6%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 2.3%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 5.2%; above 450 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 60.2%.

[0153] Comparative Example 5

[0154] The expansion and compression-resistant material was prepared according to the method described in Example 6, except that in the preparation of the third mixture S3, 0.25g of sodium dodecylbenzenesulfonate was added, the speed was adjusted to 300rpm, and the mixture was stirred for 60min.

[0155] The intumescent compressive strength material prepared in Comparative Example 6 comprises a porous structure formed by the curing of thermosetting resin and water sealed within the porous structure; the pore size of the porous structure is 1.2–1.5 mm, and the porosity of the intumescent compressive strength material is 3%; using DSC measurement, at 200–270 °C, the weight loss rate of the intumescent compressive strength material at the first weight loss peak is 0.9%; at 360–370 °C, the weight loss rate of the intumescent compressive strength material at the second weight loss peak is 1.2%; above 450 °C, the weight loss rate of the intumescent compressive strength material at the third weight loss peak is 69.3%.

[0156] Test example:

[0157] The testing method of this invention is as follows:

[0158] 1. Test method for curing rate

[0159] Let the total mass of the expanded compressive strength material after curing be m1, and the total mass of all components before curing be m0. Calculate the curing rate T of the expanded compressive strength material. m :

[0160]

[0161] 2. Density testing methods

[0162] The expansion and compressive strength materials prepared in the examples and comparative examples were made into test samples according to a mold with specifications of 60mm×60mm×30mm. The original volume (denoted as V0) and the volume after expansion at 150℃ (denoted as V1) were tested using the displacement method. The density was calculated according to the mass-volume formula.

[0163] Using the testing method of the present invention described above, the curing rate and density of Examples 1 to 10 and Comparative Examples 1 to 5 were tested, and the test results are shown in Table 1 below.

[0164] Table 1. Curing rate and density tests of Examples 1-10 and Comparative Examples 1-5

[0165]

[0166]

[0167] Examples 1-10 exhibited high curing rates, generally maintaining 98.9% or higher. Comparative Examples 1 and 3 also maintained high curing rates. Comparative Example 2, lacking water, achieved a curing rate as high as 99.5%. Comparative Example 4 had a lower curing rate, below 90%, primarily due to insufficient stirring in the preparation of the third mixture. Insufficient stirring speed and time resulted in larger pore sizes and lower porosity, preventing water from being fully encapsulated within the porous structure. Water floated on the surface of the cured molecules and evaporated at high temperatures during the curing process. Comparative Example 5 further reduced the stirring speed, resulting in even larger pore sizes and lower porosity. Although the stirring time was increased, the curing rate decreased further, indicating that stirring speed significantly affects the curing rate. At 150°C, Examples 1-10 had lower densities and better expansion effects; Comparative Examples 2, 4, and 5 had higher densities and either did not expand or had poor expansion effects.

[0168] 3. Compressive strength test method

[0169] The expansion and compressive strength materials prepared in the examples and comparative examples were made into test samples according to a mold with a specification of 60mm×60mm×30mm. The high temperature universal testing machine was used to test the compressive strength of the samples at room temperature, high temperature of 90℃ and 180℃ respectively. (Note: Before the high temperature test, silicone oil was applied to the inner cavity of the test to prevent the high temperature expansion and compressive strength material from sticking to the instrument.)

[0170] 4. Tensile strength test method

[0171] The expansion and compression-resistant materials obtained in the examples and comparative examples were made into test samples according to a dumbbell mold with a length of 30cm. The tensile strength of the samples was tested at room temperature, 90°C and 180°C using a high-temperature universal testing machine with a test speed of 5mm / min and an arbitration test speed of 2mm / min.

[0172] Using the test method of the present invention described above, the compressive strength and tensile strength of Examples 1 to 10 and Comparative Examples 1 to 5 were tested, and the test results are shown in Table 2 below.

[0173] Table 2 Mechanical property tests of Examples 1-10 and Comparative Examples 1-5

[0174]

[0175]

[0176] As shown in Table 2, the mechanical strength (including compressive and tensile strength) loss at 90℃ and 180℃ in Examples 1-10 was relatively small, especially the mechanical strength loss at high temperature (180℃). The compressive strength retention rate was above 23%, and the tensile strength retention rate was above 15%. In Example 10, because the curing agent of the expandable compressive-resistant material was added all at once, instead of in stages as in Examples 1-9, both the compressive and tensile strength retention rates at 180℃ were reduced, and the mechanical strength decreased after high temperature. In Comparative Example 1, because no accelerator was added, the curing time of the expandable compressive-resistant material was significantly prolonged, exceeding 120 hours. In Comparative Example 2, because no water was added and no steam-driven process was used, the mechanical properties at room temperature were unaffected, but the compressive and tensile strength retention rates at 180℃ were extremely low, and the mechanical strength decreased significantly after high temperature. Comparative Example 3, due to the absence of a foaming agent in the intumescent compressive material, could not fully realize the steam-driven process. Its mechanical properties at room temperature were unaffected, but the retention rates of compressive and tensile strength at 180℃ were low, and the mechanical strength decreased significantly after high temperatures. Comparative Examples 4 and 5, due to insufficient stirring and low stirring speed during the preparation of the third mixture, water was not fully encapsulated in the porous structure and floated on the surface of the solidified molecules. During the solidification process, the water evaporated at high temperatures. Its mechanical properties at room temperature were unaffected, but the retention rates of compressive and tensile strength at 180℃ were extremely low, and the mechanical strength decreased significantly after high temperatures.

[0177] 5. Test methods for expansion rate and delayed expansion time

[0178] The expansion and compression-resistant materials prepared by the examples and comparative examples with a size of 60mm×60mm×30mm (the original volume was tested by the drainage method and denoted as V0) were placed in a dry tin foil tray and placed in a constant temperature forced-air drying oven. The initial expansion time and the time required to complete the expansion were tested at different preset temperatures. The initial expansion time was denoted as the delayed expansion time t0 of the material.

[0179] Continue testing and record the time t1 for the solidified body to fully expand. Then the expansion time t2 = t1 - t0.

[0180] After complete expansion, turn off the power to the drying oven and allow the expanded body to cool. Use the water displacement method to measure its expanded volume V1 and calculate the expansion rate.

[0181]

[0182] Using the test method of the present invention patent described above, the expansion rate, delayed expansion time, and completion expansion time of Example 6 and Comparative Examples 1 to 5 at different temperatures were tested, and the test results are shown in the table below.

[0183] Table 3. Expansion performance tests of Example 6 and Comparative Examples 1-5

[0184]

[0185] As shown in Table 3, in Comparative Example 2, because no water was added to the expanding and compressive-resistant material and a steam-driven process was not used, the expanding and compressive-resistant material did not expand. In Comparative Example 3, because no foaming agent was added to the expanding and compressive-resistant material, the steam-driven process could not be fully realized, resulting in a low expansion rate and a long expansion time for the expanding and compressive-resistant material. In Comparative Examples 4 and 5, due to insufficient stirring and low stirring speed during the preparation of the third mixture, the water was not fully encapsulated in the porous structure and floated on the surface of the solidified molecules. During the solidification process, the water evaporated at high temperature, resulting in a low expansion rate and a long expansion time for the expanding and compressive-resistant material.

[0186] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. An expansion-resistant compressive material, characterized in that, The expansion and pressure-resistant material comprises a porous structure formed by the curing of thermosetting resin and water sealed within the porous structure; The porous structure has a pore size of 60μm to 400μm, and the expansion and compressive strength material has a porosity of 8 to 30%. DSC measurements show that the expansion and compressive strength material has a first weight loss peak in the range of 100℃ to 300℃, a second weight loss peak in the range of 320℃ to 380℃, and a third weight loss peak in the range of 400℃ to 500℃. The weight loss rate of the expansion and compressive strength material at the first weight loss peak is <4%, the weight loss rate at the second weight loss peak is 4% to 20%, and the weight loss rate at the third weight loss peak is 21% to 55%.

2. The expansion-resistant compressive material according to claim 1, characterized in that, The thermosetting resin includes one or more of epoxy resin, phenolic resin, polyetherketone resin, and polyimide resin; And / or, the pore size of the porous structure is 100μm to 320μm, and the porosity of the expansion and compressive strength material is 10% to 25%.

3. The method for preparing the expansion-resistant and compressive-resistant material according to claim 1 or 2, characterized in that, Includes the following steps: Preparation of the first mixture S1: The thermosetting resin is mixed with the first curing agent to obtain the first mixture; Preparation of the second mixture S2: Mix the second curing agent with water to obtain the second mixture; Preparation of the third mixture S3: Mix the first mixture and the second mixture evenly, add the accelerator and foaming agent, and stir for ≥10 minutes at 60℃~85℃ with the speed adjusted to 700rpm~3000rpm to obtain the third mixture; S4 Curing: Curing the third mixture to obtain the expansion and compression resistant material.

4. The method for preparing the expansion-resistant material according to claim 3, characterized in that, In step S1, the thermosetting resin is heated to 60°C to 85°C, the first curing agent is added, the temperature is adjusted to 5°C to 30°C above the melting point of the first curing agent, and after the first curing agent is completely dissolved, it is stirred at a stirring speed of 200 to 400 rpm for 20 to 60 minutes, and then adjusted to 60°C to 85°C to obtain the first mixture. And / or, step S2 includes step S2-1, step S2-2, or step S2-3; Step S2-1: The second curing agent is a solid with a melting point ≥90℃. Add the second curing agent to the solution and adjust the temperature to 5℃~30℃ above the melting point of the second curing agent. After the second curing agent is completely dissolved, adjust the temperature to 60℃~85℃, add water, and stir at a stirring speed of 200~400rpm for 20~60min to obtain the second mixture. Step S2-2: The second curing agent is a solid with a melting point <90℃. Add the second curing agent to water and heat it to 5℃~10℃ above the melting point of the second curing agent. After the second curing agent is completely dissolved, adjust the temperature to 60℃~85℃ and stir at a stirring speed of 200~400rpm for 20~60min to obtain the second mixture. Step S2-3: The second curing agent is a liquid. Adjust the temperature to 60℃~85℃, add water to the second curing agent, and stir at a stirring speed of 200~400rpm for 20~60min to obtain the second mixture. And / or, in step S3, the second mixture is added to the first mixture, along with an accelerator and a foaming agent, and stirred for 10-30 minutes to obtain a third mixture; And / or, in step S4, the curing includes two or three of the following: first curing, second curing, and third curing; the first curing is carried out at a constant temperature of 100℃~110℃ for 2h~8h; the second curing is carried out at a constant temperature of 120℃~130℃ for 0.5h~4h; and the third curing is carried out at a constant temperature of 140℃~160℃ for 0.5h~4h. And / or, the first curing agent and the second curing agent may be the same or different, and each is independently selected from one or more of acid anhydride curing agents, phenolic curing agents, and aromatic polyamine curing agents; And / or, the mass ratio of the first curing agent to the second curing agent is (0.75~3):

1.

5. The method for preparing the expansion-resistant compressive material according to claim 3 or 4, characterized in that, Based on 100 parts by weight of thermosetting resin, the total amount of the first curing agent and the second curing agent is 50 to 100 parts by weight, the amount of accelerator is 0 to 2 parts by weight, the amount of water is 10 to 50 parts by weight, and the amount of foaming agent is 0.1 to 3 parts by weight.

6. The method for preparing the expansion-resistant compressive material according to any one of claims 3-5, characterized in that, The accelerator comprises one or more of triethanolamine, dimethylaniline, and 2,4,6-tris(dimethylaminomethyl)phenol; And / or, the water is fresh water or salt water, preferably, the water contains a foam enhancer; And / or, the foaming agent comprises one or more of anionic foaming agents, cationic foaming agents, and nonionic foaming agents.

7. The method for preparing the expansion-resistant material according to claim 6, characterized in that, The amount of the solution used is 10 to 20 parts by weight; and / or, the solution contains at least one of a liquid resin curing agent and a liquid resin toughening agent; preferably, the solution contains at least one of a modified aromatic amine liquid curing agent, a modified phenolic curing agent, and an alkenyl succinic anhydride.

8. The method for preparing the expansion-resistant compressive material according to claim 6, characterized in that, The epoxy resin comprises one or more of the following: glycidyl ether epoxy resin, glycidyl amine epoxy resin, glycidyl ester epoxy resin, imide modified epoxy resin, and phenolic modified epoxy resin. And / or, the anhydride curing agent comprises one or more of maleic anhydride, alkenyl succinic anhydride, phthalic anhydride, cyclopentadienoic dianhydride, and methyl hexahydrophthalic anhydride; And / or, the foam enhancer comprises one or more of surfactant enhancers, drilling fluid surface viscosity enhancers, or surface shear strength enhancers; preferably, the foam enhancer comprises one or two of surfactants or thickening and shearing agents; more preferably, the mass content of the foam enhancer is 0.1% to 1% based on the weight of the water; And / or, the anionic foaming agent is selected from one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium fatty acid methyl ester ethoxylate sulfonate, fatty alcohol glyceryl ether sulfonate, or α-olefin sulfonate. And / or, the cationic foaming agent is selected from one or more of hexadecyltrimethylammonium bromide, fatty ether triethanolamine salt, and alkylbenzene sulfonic acid triethanolamine salt; And / or, the nonionic foaming agent is selected from one or more of coconut oil diethanolamide, cocamidopropyl dimethyl tertiary amine and oleamide propyl dimethyl tertiary amine.

9. The method for preparing the expansion-resistant compressive material according to claim 8, characterized in that, The epoxy resin comprises one or more of bisphenol A diglycidyl ether, phenolic epoxy resin, and imide epoxy resin. And / or, the surfactant-based foam enhancer comprises one or more of polysorbate, sorbitan monooleate, oleyl alcohol polyoxyethylene ether, and dodecyl oleate; And / or, the thickening and cutting agent-type foam reinforcing agent comprises one or more of hydroxyethyl methyl cellulose, polyacrylamide, and sodium carboxymethyl starch; And / or, the anionic foaming agent is selected from one or more of sodium dodecylbenzene sulfonate, fatty alcohol glyceryl ether sulfonate, or α-olefin sulfonate.

10. An intumescent, pressure-resistant, leak-sealing agent, characterized in that, The sealing agent includes the expansion and pressure-resistant material as described in claim 1 or 2, or the expansion and pressure-resistant material prepared by any one of claims 3-9.

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