A fiber sealing material and a method for preparing the same

Abstract

The application provides a kind of fiber sealing material and its preparation method, belong to sealing material technical field.The preparation method of fiber sealing material provided by the application includes the following steps: the solution of fiber, solvent, microfibrillated cellulose, latex, additive, filler and coupling agent modified microfibrillated cellulose is mixed to obtain slurry;The slurry and flocculating agent are mixed, then shearing is carried out to obtain microfloc polymer;The microfloc polymer and the solution of coupling agent modified inorganic microparticle are mixed, papermaking is carried out to obtain fiber sealing material.The application adds microfibrillated cellulose in slurry system, uses modified microparticle retention system, through the synergistic effect of hydrogen bond combination between microfibrillated cellulose and slurry system and modified microparticle retention system retention, the flatness of fiber sealing material surface and the compatibility and binding force between fiber sealing material surface and glue line are improved, so as to improve the firmness of fiber sealing material surface printing glue line.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sealing materials, and particularly relates to a fiber sealing material and a preparation method thereof. BACKGROUND

[0002] After the sealing material is made into a sealing gasket, the sealing gasket is embedded into a flange joint to bear the joint displacement and plays a role of sealing medium. The sealing material is widely used in the connection of various vehicles, mechanical equipment and various pipelines, and has an important influence on the use performance of vehicles and machinery and the safe operation and environmental hygiene in the industrial production process. The fiber sealing material is a high-efficiency and environmentally-friendly sealing material. In the use process of the gasket made of the sealing material, a certain shape of glue line is required to be screen printed on the surface of the gasket to make up for the insufficient interface sealing capacity of the sealing material, but the fiber sealing material is not firmly adhered to the glue line. Therefore, how to improve the fiber sealing material to avoid the cracking and falling of the glue line becomes a technical problem to be solved in the field. SUMMARY

[0003] The present application provides a fiber sealing material and a preparation method thereof. The fiber sealing material prepared by the preparation method provided by the present application can be firmly adhered to the glue line, thereby avoiding the cracking and falling of the glue line.

[0004] In order to achieve the above-mentioned application purpose, the present application provides the following technical scheme:

[0005] The present application provides a preparation method of a fiber sealing material, comprising the following steps:

[0006] (1) mixing a fiber, a solvent, microfibrillated cellulose, latex, an additive, a filler and a solution of coupling agent modified microfibrillated cellulose to obtain a slurry;

[0007] (2) mixing the slurry obtained in the step (1) and a flocculating agent, and then shearing to obtain microfloc;

[0008] (3) mixing the microfloc obtained in the step (2) and a solution of coupling agent modified inorganic microparticles, and papermaking to obtain the fiber sealing material.

[0009] Preferably, the absolute dry mass ratio of the fiber, the latex, the additive and the filler in the step (1) is (5-40):(5-25):(2-10):(10-80).

[0010] Preferably, the diameter of the microfibrillated cellulose in the step (1) is 10-200nm, and the aspect ratio of the microfibrillated cellulose is 100-20000.

[0011] Preferably, the mass of the microfibrillated cellulose in the step (1) is 0.1-10% of the mass of the fiber.

[0012] Preferably, the filler in the step (1) is at least one of calcium carbonate, talc, white carbon black, kaolin, wollastonite, mica and calcined clay.

[0013] Preferably, the solid content of the coupling agent modified microfibrillated cellulose solution in the step (1) is 0.1-10%, and the mass of the coupling agent modified microfibrillated cellulose solution is 0.1-10% of the mass of the fibers.

[0014] Preferably, the flocculating agent in the step (2) is a cationic polymer, and the mass of the flocculating agent is 0.01-0.5% of the absolute dry mass of the slurry.

[0015] Preferably, the solid content of the coupling agent modified inorganic microparticle solution in the step (3) is 0.1-20%, and the mass of the coupling agent modified inorganic microparticle solution is 0.1-2% of the absolute dry mass of the slurry.

[0016] Preferably, the inorganic microparticles in the coupling agent modified inorganic microparticle solution in the step (3) are at least one of silica, bentonite and montmorillonite.

[0017] The application also provides a fiber sealing material prepared by the preparation method.

[0018] This invention provides a method for preparing a fiber sealing material, comprising the following steps: mixing fibers, solvent, microfibrillated cellulose, latex, additives, fillers, and a coupling agent-modified microfibrillated cellulose solution to obtain a slurry; mixing the slurry with a flocculant and then shearing it to obtain microflocs; mixing the microflocs with a coupling agent-modified inorganic microparticle solution and then papermaking to obtain the fiber sealing material. This invention adds microfibrillated cellulose to the slurry system and employs a modified microparticle retention aid system. Through hydrogen bonding between the microfibrillated cellulose and the slurry system, and the synergistic effect of the modified microparticle retention aid system, the smoothness of the fiber sealing material surface and the compatibility and adhesion between the fiber sealing material surface and the adhesive lines are improved, thereby enhancing the adhesion of the printed adhesive lines on the fiber sealing material surface. Furthermore, the microfibrillated cellulose has a small size, large specific surface area, and extremely rich surface free hydroxyl content. Numerous hydrogen bonds can form between microfibrillated cellulose fibers and between microfibrillated cellulose and fibers and hydroxyl-containing components, resulting in strong adhesion. Mixing the slurry and flocculant allows for over-flocculation of the system, followed by shearing to break up the flocs into microflocculated particles. The process involves adding a coupling agent-modified inorganic microparticle solution to reorganize the micro-flocculated material into a superflocculated structure. This significantly improves the retention and filtration performance of the slurry, enhances the uniformity and surface smoothness of the fiber sealing material, and increases the contact area between the printing adhesive thread and the fiber sealing material. Furthermore, the coupling agent chemically modifies the surface of the microfibrillated cellulose and inorganic microparticles. The active groups (such as hydroxyl and amino groups) at one end of the molecular chain chemically bond with the surface of the microfibrillated cellulose and inorganic microparticles, forming a stable modified layer. The other end forms a tight chemical bond with the printing adhesive thread, improving the interfacial interaction and bonding between the fiber sealing material surface and the printing adhesive thread through molecular bridging, thereby greatly enhancing the adhesion of the printing adhesive thread. Experimental results show that when the fiber sealing material prepared by the method provided by this invention is cut into gaskets and installed on a flange, placed in an oven at 120°C for 22 hours, removed, and dried to room temperature, the flange is opened with a torque measuring instrument, and the peeling force is 0N. Two-component room temperature vulcanizing silicone liquid is directly printed on the surface of the fiber sealing material. After the adhesive line is cured, the adhesive line is scraped by hand and scratched with a fingernail. The adhesive line adheres very firmly to the fiber sealing material and will not crack or fall off. Attached Figure Description

[0019] Figure 1 The photos show the adhesive lines directly printed on the surface of the fiber sealing material prepared in Example 1, as well as the adhesive lines after being scratched by hand and after being picked off with a fingernail.

[0020] Figure 2 The photos show the adhesive lines directly printed on the surface of the fiber sealing material prepared in Example 2, as well as the adhesive lines after being scratched by hand and after being picked off with a fingernail.

[0021] Figure 3 The photos show the adhesive lines directly printed on the surface of the fiber sealing material prepared in Example 3, as well as the adhesive lines after being scratched by hand and after being picked off with a fingernail.

[0022] Figure 4 The photos show the adhesive lines directly printed on the surface of the fiber sealing material prepared in Example 4, and the adhesive lines after being scratched by hand and after being picked off with a fingernail.

[0023] Figure 5 The photos show the adhesive lines directly printed on the surface of the fiber sealing material prepared in Example 5, as well as the adhesive lines after being scratched by hand and after being picked off with a fingernail.

[0024] Figure 6 The images show photos of the adhesive lines directly printed on the surface of the fiber sealing material prepared in Comparative Example 1, as well as photos of the adhesive lines after being scratched by hand and after being picked off with fingernails. Detailed Implementation

[0025] This invention provides a method for preparing a fiber sealing material, comprising the following steps:

[0026] (1) Mix the fiber, solvent, microfibrillated cellulose, latex, additives, filler and coupling agent modified microfibrillated cellulose solution to obtain slurry;

[0027] (2) Mix the slurry obtained in step (1) with the flocculant, and then shear it to obtain micro-flocs;

[0028] (3) The microflocs obtained in step (2) are mixed with the inorganic microparticle solution modified by coupling agent and paper is made to obtain fiber sealing material.

[0029] The present invention does not have any special limitations on the source of the raw materials, and commercially available products known to those skilled in the art can be used.

[0030] This invention involves mixing fibers, solvents, microfibrillated cellulose, latex, additives, fillers, and a coupling agent-modified microfibrillated cellulose solution to obtain a slurry.

[0031] In this invention, the fiber is preferably at least one of softwood chemical pulp fiber, hardwood chemical pulp fiber, hemp pulp fiber, aramid fiber, carbon fiber, acrylic fiber, aramid fiber, phenolic fiber, sepiolite fiber, aluminum silicate fiber, glass fiber, and ceramic fiber; the width of the fiber is preferably 1 to 50 μm; and the length of the fiber is preferably 0.05 to 5 mm.

[0032] In one embodiment, the width of the fiber can be 10μm, 20μm, 25μm, 26μm, 30μm, 35μm or 40μm; the length of the fiber can be 0.1mm, 1mm, 2mm, 2.5mm, 3mm, 3.5mm or 4mm.

[0033] In this invention, when the fibers are hemp pulp fibers and aramid fibers, the preferred mass ratio of the hemp pulp fibers to the aramid fibers is (5-9):(1-5). As one embodiment, the mass ratio of the hemp pulp fibers to the aramid fibers can be (6-8):(2-4).

[0034] In this invention, when the fibers are hemp pulp fiber, aramid fiber, and carbon fiber, the preferred mass ratio of the hemp pulp fiber, aramid fiber, and carbon fiber is (7-9):(0.5-1.5):(0.5-1). As one embodiment, the mass ratio of the hemp pulp fiber, aramid fiber, and carbon fiber can be 8.5:1:0.5.

[0035] In this invention, when the fibers are softwood chemical pulp fibers, aramid fibers, and glass fibers, the preferred mass ratio of the softwood chemical pulp fibers, aramid fibers, and glass fibers is (5-7):(1-2):(1-2). As one embodiment, the mass ratio of the softwood chemical pulp fibers, aramid fibers, and glass fibers can be (6-7):2:1.

[0036] In this invention, when the fiber is coniferous chemical pulp fiber, sepiolite fiber and carbon fiber, the preferred mass ratio of the coniferous chemical pulp fiber, sepiolite fiber and carbon fiber is (7-8):(1-2):(1-2).

[0037] In this invention, when the fibers are softwood chemical pulp fibers, aramid fibers, carbon fibers, and ceramic fibers, the preferred mass ratio of the softwood chemical pulp fibers, aramid fibers, carbon fibers, and ceramic fibers is (6-8):(1-2):(0.5-1):(0.5-1.5). As one embodiment, the mass ratio of the softwood chemical pulp fibers, aramid fibers, carbon fibers, and ceramic fibers can be 7:1.5:0.5:1.

[0038] In this invention, the solvent is preferably water. There is no particular limitation on the amount of water used; it can be adjusted according to the amount of fiber used to ensure that the fiber disintegration concentration is within the range of 1-6%.

[0039] In this invention, the diameter of the microfibrillated cellulose is preferably 10-200 nm; the aspect ratio of the microfibrillated cellulose is preferably 100-20000. As one embodiment, the diameter of the microfibrillated cellulose can be 30 nm, 50 nm, 60 nm, 70 nm, 100 nm, 150 nm, or 180 nm; the aspect ratio of the microfibrillated cellulose can be 500, 1000, 2000, 3000, 3500, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, or 19000.

[0040] In this invention, the microfibrillated cellulose is preferably obtained from plant fibers through a mechanical process of highly fine fibrillation. This invention does not impose any particular limitations on the mechanical process of highly fine fibrillating the plant fibers, as long as the diameter and aspect ratio of the microfibrillated cellulose meet the aforementioned requirements.

[0041] In this invention, the mass of the microfibrillated cellulose is preferably 0.1% to 10% of the fiber mass. As one embodiment, the mass of the microfibrillated cellulose can be 0.3%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9% of the fiber mass. Limiting the mass of the microfibrillated cellulose within the above range further improves the bonding strength between the fiber sealing material and the adhesive thread.

[0042] In this invention, the latex is preferably at least one selected from styrene-butadiene latex, carboxylated styrene-butadiene latex, nitrile latex, carboxylated nitrile latex, chloroprene latex, acrylic latex, and natural latex; the solid content of the latex is preferably 40-50%; and the viscosity of the latex is preferably 20-200 cP. In this invention, the latex serves as an adhesive to improve the bonding strength between the fiber sealing material and the adhesive thread.

[0043] In one embodiment, the solid content of the latex can be 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, or 49%; and the viscosity of the latex can be 50 cP, 55 cP, 60 cP, 85 cP, 100 cP, or 150 cP.

[0044] In this invention, the additives preferably include at least one of a vulcanizing agent, an accelerator, a activator, an anti-aging agent, a pigment, and a dye; the vulcanizing agent is preferably sulfur; the accelerator is preferably at least one of a thiazole, a dithiophosphate, and a thiuram; the activator is preferably zinc oxide or stearic acid; the anti-aging agent is preferably styrene diphenylamine, p,p'-diisopropylphenyl diphenylamine, 2-thiol-methylbenzimidazole, or 2,6-di-tert-butyl-p-cresol; the pigment is preferably carbon black or iron oxide; and the dye is preferably an organic dye.

[0045] In this invention, the particle size of the pigment is preferably 1 to 200 μm. As one embodiment, the particle size of the pigment can be 7 μm, 10 μm, 50 μm, 100 μm, or 150 μm.

[0046] The present invention does not specifically limit the type of dye; it can be adjusted according to the actual required color.

[0047] In this invention, the filler is preferably at least one selected from calcium carbonate, talc, silica, kaolin, wollastonite, mica, and calcined clay; the particle size of the filler is preferably 2–50 μm. As one embodiment, the particle size of the filler can be 7 μm, 10 μm, 15 μm, 20 μm, 30 μm, or 40 μm.

[0048] In this invention, the preferred oven-dry mass ratio of the fiber, latex, additives, and filler is (5-40):(5-25):(2-10):(10-80). As one embodiment, the oven-dry mass ratio of the fiber, latex, additives, and filler can be (10-35):(10-20):(3-8):(20-70), or it can be 20:15:5:60, 25:12:3:70, 30:20:6:44, 30:15:6:49, or 30:15:7:48. By limiting the oven-dry mass ratio of the fiber, latex, additives, and filler to the above range, this invention can improve the bonding strength between the fiber sealing material and the adhesive thread.

[0049] The present invention does not impose any special limitation on the amount of each substance in the adjuvant; any amount known to those skilled in the art can be used.

[0050] In this invention, the solid content of the coupling agent-modified microfibrillated cellulose solution is preferably 0.1% to 10%; the mass of the coupling agent-modified microfibrillated cellulose solution is preferably 0.1% to 10% of the fiber mass. As one embodiment, the solid content of the coupling agent-modified microfibrillated cellulose solution can be 1%, 2%, 2.8%, 3%, 3.3%, 4%, 5%, 6%, 6.5%, 7%, 8%, or 9%; the mass of the coupling agent-modified microfibrillated cellulose solution can be 0.3%, 1%, 2%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, or 9% of the fiber mass. By limiting the solid content and mass of the coupling agent-modified microfibrillated cellulose solution within the above ranges, this invention can improve the bonding strength between the fiber sealing material and the adhesive thread.

[0051] In this invention, the preferred method for preparing the coupling agent modified microfibrillated cellulose solution is to mix the coupling agent and water, and then add the microfibrillated cellulose.

[0052] In this invention, the coupling agent is preferably at least one selected from 3-aminopropyltriethoxysilane (KH-550), γ-(methacryloyloxy)propyltriethoxysilane (KH-560), γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and γ-(methacryloyloxy)-propyltrimethoxysilane; the mass of the coupling agent is preferably 0.01% to 200% of the mass of the microfibrillated cellulose. Limiting the mass of the coupling agent within the above range improves the modification effect of the microfibrillated cellulose, thereby further enhancing the bonding strength between the fiber sealing material and the adhesive thread.

[0053] In one embodiment, the mass of the coupling agent can be 0.2%, 20%, 30%, 50%, 80%, 100%, 120%, 150%, 180%, or 190% of the mass of the microfibrillated cellulose.

[0054] In this invention, the diameter of the microfibrillated cellulose is preferably 10-200 nm; the aspect ratio of the microfibrillated cellulose is preferably 100-20000. As one embodiment, the diameter of the microfibrillated cellulose can be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 100 nm, or 150 nm; the aspect ratio of the microfibrillated cellulose can be 500, 1000, 2000, 3000, 4000, 5000, 6000, 6500, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, or 19000.

[0055] In this invention, the microfibrillated cellulose is preferably obtained from plant fibers through a mechanical process of highly fine fibrillation. This invention does not impose any particular limitations on the mechanical process of highly fine fibrillating the plant fibers, as long as the diameter and aspect ratio of the microfibrillated cellulose meet the aforementioned requirements.

[0056] In this invention, the mixing of the coupling agent and water is preferably carried out under stirring conditions; the stirring rate is preferably 100–2000 rpm; and the stirring time is preferably 5–30 min. As one embodiment, the stirring rate can be 500 rpm, 600 rpm, 800 rpm, 1000 rpm, 1200 rpm, 1500 rpm, 1600 rpm, or 2000 rpm; and the stirring time can be 10 min, 15 min, 20 min, or 25 min. By limiting the stirring process parameters within the above ranges, this invention can improve the degree of mixing of the raw materials.

[0057] In this invention, the microfibrillated cellulose is preferably added under stirring conditions; the stirring time is preferably 20–100 min; and the stirring rate is preferably 100–2000 rpm. As one embodiment, the stirring rate can be 500 rpm, 600 rpm, 800 rpm, 1000 rpm, 1200 rpm, 1500 rpm, or 1600 rpm; and the stirring time can be 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, or 90 min.

[0058] In this invention, the preferred mixture of the fiber, solvent, microfibrillated cellulose, latex, additives, filler, and coupling agent-modified microfibrillated cellulose solution is:

[0059] The fibers and solvents are mixed for the first disintegration, then microfibrillated cellulose is added for the second disintegration, followed by the addition of latex, additives and fillers for the third disintegration, and finally a coupling agent-modified microfibrillated cellulose solution is added for the fourth disintegration.

[0060] In this invention, the preferred time for the first dissolving step is 10–60 min; the preferred time for the second dissolving step is 5–15 min; the preferred time for the third dissolving step is 10–60 min; and the preferred time for the fourth dissolving step is 5–15 min. This invention does not impose any particular temperature limit on the first, second, third, and fourth dissolving steps; they can be performed at room temperature. Limiting the times for the first, second, third, and fourth dissolving steps to the above ranges improves the degree of mixing of the raw materials.

[0061] The present invention does not impose any special limitation on the stirring rate of the first, second, third and fourth dispersive processes. The raw materials can be mixed evenly by means of stirring operations known to those skilled in the art.

[0062] In one implementation, the time for the first clearing can be 20 min, 25 min, 30 min, 40 min, 45 min, 50 min, or 55 min; the time for the second clearing can be 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, or 14 min; the time for the third clearing can be 20 min, 30 min, 35 min, 40 min, 45 min, 50 min, or 55 min; and the time for the fourth clearing can be 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, or 14 min.

[0063] After obtaining the slurry, the present invention mixes the slurry with a flocculant and then shears it to obtain micro-flocs.

[0064] In this invention, the flocculant is preferably a cationic polymer; the cationic polymer is preferably polyacrylamide; and the mass of the flocculant is preferably 0.01 to 0.5% of the oven-dry mass of the slurry. Limiting the mass of the flocculant within the above range improves the flocculation effect, thereby further enhancing the bonding strength between the fiber sealing material and the adhesive thread.

[0065] In one embodiment, the mass of the flocculant can be 0.03%, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, or 0.4% of the oven-dry mass of the slurry.

[0066] The present invention does not impose any special limitation on the molecular weight of the polyacrylamide, and any polyacrylamide well known to those skilled in the art can be used.

[0067] In one embodiment, the molecular weight of the polyacrylamide can be 2 million, 3 million, or 4 million.

[0068] The present invention does not impose any special limitations on the operation of mixing the slurry and flocculant; any technical solution for preparing the mixture well known to those skilled in the art can be used.

[0069] In this invention, the shearing is preferably performed using a slurry pump or a pressure screen. This invention does not impose any particular limitations on the operation of using a slurry pump or pressure screen; any operation well-known to those skilled in the art can be used.

[0070] After obtaining the microflocs, the present invention mixes the microflocs with an inorganic microparticle solution modified by a coupling agent and then uses the mixture for papermaking to obtain a fiber sealing material.

[0071] In this invention, the solid content of the coupling agent-modified inorganic microparticle solution is preferably 0.1% to 20%; the mass of the coupling agent-modified inorganic microparticle solution is preferably 0.1% to 2% of the oven-dry mass of the slurry. By limiting the solid content and mass of the coupling agent-modified inorganic microparticle solution within the above ranges, this invention can further improve the bonding strength between the fiber sealing material and the adhesive thread.

[0072] In one embodiment, the solid content of the coupling agent-modified inorganic microparticle solution can be 1%, 2%, 3%, 4%, 5%, 6%, 6.5%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, or 19%; the mass of the coupling agent-modified inorganic microparticle solution can be 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, or 1.9% of the oven-dry mass of the slurry.

[0073] In this invention, the preferred method for preparing the coupling agent modified inorganic microparticle solution is to mix the coupling agent and water, and then add inorganic microparticles.

[0074] In this invention, the coupling agent is preferably at least one selected from 3-aminopropyltriethoxysilane (KH-550), 3-propyltrimethoxysilane, 3-propyltriethoxysilane, polyethyl silicate, methyltrimethoxysilane, and titanate coupling agents; the mass of the coupling agent is preferably 0.1% to 300% of the mass of inorganic microparticles. Limiting the mass of the coupling agent within the above range further improves the modification effect, thereby further enhancing the bonding strength between the fiber sealing material and the adhesive thread.

[0075] In one embodiment, the polyethyl silicate can be polyethyl silicate Si28; and the methyltrimethoxysilane can be methyltrimethoxysilane D20.

[0076] In one embodiment, the mass of the coupling agent can be 1%, 10%, 15%, 20%, 30%, 50%, 80%, 100%, 120%, 150%, 180%, 190%, 200%, 250%, or 280% of the mass of the inorganic microparticles.

[0077] In this invention, the inorganic microparticles are preferably at least one of silica, bentonite, and montmorillonite; the inorganic microparticles are preferably nano-sized or submicron-sized; and the particle size of the inorganic microparticles is preferably 1–600 nm.

[0078] In one embodiment, the particle size of the inorganic microparticles can be 10nm, 20nm, 50nm, 100nm, 200nm, 300nm, 400nm or 500nm.

[0079] In this invention, the mixing of the coupling agent and water is preferably carried out under stirring conditions; the stirring rate is preferably 100–3000 rpm; and the stirring time is preferably 5–30 min. As one embodiment, the stirring rate can be 600 rpm, 1000 rpm, 1500 rpm, 1600 rpm, or 2000 rpm; and the stirring time can be 10 min, 15 min, or 20 min. By limiting the stirring process parameters within the above ranges, this invention can improve the degree of mixing of the raw materials.

[0080] In this invention, the inorganic microparticles are preferably added under stirring conditions; the stirring time is preferably 20–100 min; and the stirring rate is preferably 100–3000 rpm. As one embodiment, the stirring rate can be 600 rpm, 1000 rpm, 1500 rpm, 1600 rpm, or 2000 rpm; and the stirring time can be 15 min, 20 min, 30 min, 35 min, 40 min, 60 min, or 80 min.

[0081] The present invention does not have any special limitations on the operation of mixing the microflocs and the coupling agent modified inorganic microparticle solution; any technical solution for preparing the mixture well known to those skilled in the art can be used.

[0082] In this invention, the papermaking process is preferably carried out on a paper machine. This invention does not specify a particular type of paper machine; any instrument or equipment well-known to those skilled in the art can be used.

[0083] The present invention does not impose any special limitations on the papermaking operation; any operation known to those skilled in the art can be used.

[0084] In one implementation, the papermaking process can be carried out sequentially, including pulping, wire forming, pressing, drying, and vulcanization.

[0085] This invention adds microfibrillated cellulose to the slurry system and employs a modified microparticle retention aid system. Through hydrogen bonding between the microfibrillated cellulose and the slurry system, and the synergistic effect of the modified microparticle retention aid system, the smoothness of the fiber sealing material surface and the compatibility and adhesion between the fiber sealing material surface and the adhesive lines are improved, thereby enhancing the adhesion of the printed adhesive lines on the fiber sealing material surface. Furthermore, the microfibrillated cellulose has a small size, large specific surface area, and extremely rich surface free hydroxyl content. Numerous hydrogen bonds can form between microfibrillated cellulose fibers and between microfibrillated cellulose and fibers and hydroxyl-containing components, resulting in strong adhesion. Mixing the slurry and flocculant allows for over-flocculation of the system, followed by shearing to break up the flocs into microflocculated particles. The process involves adding a coupling agent-modified inorganic microparticle solution to reorganize the micro-flocculated material into a superflocculated structure. This significantly improves the retention and filtration performance of the slurry, enhances the uniformity and surface smoothness of the fiber sealing material, and increases the contact area between the printing adhesive thread and the fiber sealing material. Furthermore, the coupling agent chemically modifies the surface of the microfibrillated cellulose and inorganic microparticles. The active groups (such as hydroxyl and amino groups) at one end of the molecular chain chemically bond with the surface of the microfibrillated cellulose and inorganic microparticles, forming a stable modified layer. The other end forms a tight chemical bond with the printing adhesive thread, improving the interfacial interaction and bonding between the fiber sealing material surface and the printing adhesive thread through molecular bridging, thereby greatly enhancing the adhesion of the printing adhesive thread.

[0086] The fiber sealing material of this invention is asbestos-free, making it more environmentally friendly.

[0087] The present invention also provides a fiber sealing material prepared by the preparation method described in the above technical solution.

[0088] The fiber sealing material provided by this invention can bond firmly to the adhesive line.

[0089] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0090] Example 1

[0091] A method for preparing a fiber sealing material includes the following steps:

[0092] (1) Add water to a dispersion tank, turn on mechanical stirring at 500 rpm, add 3-aminopropyltriethoxysilane, continue stirring for 5 min after the addition, then add microfibrillated cellulose, stir at 500 rpm for 30 min to obtain a coupling agent modified microfibrillated cellulose solution with a solid content of 3.3%; wherein, the mass of 3-aminopropyltriethoxysilane is 0.2% of the mass of microfibrillated cellulose; microfibrillated cellulose is obtained by mechanically highly finely fibrillating plant fiber coniferous chemical pulp fiber; the diameter of microfibrillated cellulose is 70 nm and the aspect ratio is 1000;

[0093] (2) Add water to the dispersion tank, turn on the mechanical stirrer at 1000 rpm, add 3-aminopropyltriethoxysilane, continue stirring for 10 min after the addition, then add submicron silica, stir at 1000 rpm for 30 min to obtain a coupling agent modified inorganic microparticle solution with a solid content of 8%; wherein, the mass of 3-aminopropyltriethoxysilane is 1% of the mass of silica; the diameter of silica is 200 nm;

[0094] (3) Fiber and water were added to a dispersion tank and dissolved for 25 minutes to achieve a dissolution concentration of 2.2%. Then, 0.3% (by weight of the fiber) of microfibrillated cellulose was added and dissolved for 5 minutes. Latex, additives, and fillers were then added and dissolved for 35 minutes. Subsequently, 0.3% (by weight of the fiber) of a coupling agent-modified microfibrillated cellulose solution was added and dissolved for 5 minutes to obtain a slurry. The fibers were hemp pulp fiber and aramid fiber. The hemp pulp fiber had a length of 3 mm and a width of 26 μm, while the aramid fiber had a length of 4 mm and a width of 35 μm. The mass ratio of hemp pulp fiber to aramid fiber was 8:2. The microfibrillated cellulose was obtained from plant extracts. The microfiber is obtained by mechanically highly finely fibrillating coniferous chemical pulp fibers; the diameter of the microfibrillated cellulose is 70 nm, and the aspect ratio is 1000; the latex is chloroprene latex with a solid content of 43% and a viscosity of 55 cP; the additives are 0.3% sulfur by weight of pulp, 0.1% thiazole accelerator DM by weight of pulp, 0.2% zinc oxide by weight of pulp, 0.05% styrene diphenylamine by weight of pulp, and 0.1% carbon black by weight of pulp; the filler is kaolin with a particle size of 7 μm; the oven-dry mass ratio of fiber, latex, additives, and filler is 20:15:5:60;

[0095] (4) Add 0.2% polyacrylamide by oven-dry weight of the slurry to the slurry obtained in step (3), and then use a slurry pump to shear the slurry to obtain micro-flocs; wherein the molecular weight of the polyacrylamide is 4 million.

[0096] (5) Add an inorganic microparticle solution modified with a coupling agent of 0.6% of the oven-dry weight of the slurry to the microflocs obtained in step (4), and perform slurry flow in a headbox. Then, perform mesh forming, pressing, drying and vulcanization in sequence to obtain fiber sealing material. The vulcanization temperature is 150°C and the vulcanization time is 15 min.

[0097] The fiber sealing material prepared in Example 1 was cut into gaskets and installed on the flange. After being placed in an oven at 120°C for 22 hours, it was taken out, dried to room temperature, and the flange was opened with a torque measuring instrument. The peeling force was 0N (i.e., it could be peeled off without applying external force).

[0098] Two-component room temperature vulcanizing silicone liquid was directly printed on the surface of the fiber sealing material prepared in Example 1. After the adhesive line cured, photos of the adhesive line after scraping it by hand and after scratching it with a fingernail are shown below. Figure 1 As shown.

[0099] from Figure 1 As can be seen, the adhesive thread adheres very firmly to the fiber sealing material, and the adhesive thread will not crack or fall off.

[0100] Example 2

[0101] A method for preparing a fiber sealing material includes the following steps:

[0102] (1) Add water to a dispersion tank, turn on mechanical stirring at 800 rpm, add 3-aminopropyltriethoxysilane, continue stirring for 5 min after the addition, then add microfibrillated cellulose, stir at 800 rpm for 20 min to obtain a coupling agent modified microfibrillated cellulose solution with a solid content of 6.5%; wherein, the mass of 3-aminopropyltriethoxysilane is 20% of the mass of microfibrillated cellulose; microfibrillated cellulose is obtained by mechanically highly finely fibrillating plant fiber coniferous chemical pulp fiber; the diameter of microfibrillated cellulose is 30 nm and the aspect ratio is 10000;

[0103] (2) Add water to the dispersion tank, turn on the mechanical stirrer at 1500 rpm, add polyethyl silicate Si28, continue stirring for 10 min after the addition, then add nano-sized silica, stir at 1500 rpm for 35 min to obtain a coupling agent modified inorganic microparticle solution with a solid content of 10%; wherein, the mass of polyethyl silicate Si28 is 15% of the mass of silica; the particle size of silica is 20 nm;

[0104] (3) Fiber and water were added to a dispersion tank and dissolved for 50 min to achieve a dissolution concentration of 4.5%. Then, 3% (by weight of the fiber) of microfibrillated cellulose was added and dissolved for 12 min. Latex, additives, and fillers were then added and dissolved for 45 min. Subsequently, 2% (by weight of the fiber) of a coupling agent-modified microfibrillated cellulose solution was added and dissolved for 8 min to obtain the pulp. The fibers consisted of coniferous chemical pulp fiber, aramid fiber, and glass fiber, with a fiber length of 2.5 mm and a fiber width of 35 μm. The mass ratio of coniferous chemical pulp fiber, aramid fiber, and glass fiber was 7:2:1. The microfibrillated cellulose was obtained from plant extracts. The microfiber is obtained by mechanically highly finely fibrillating coniferous chemical pulp fibers; the diameter of the microfibrillated cellulose is 30 nm, and the aspect ratio is 10000; the latex is styrene-butadiene latex with a solid content of 48% and a viscosity of 85 cP; the additives are 1% sulfur, 1% ZBTP dithiophosphate, 1% stearic acid, 1% 2-mercaptomethylbenzimidazole, and 1.5% iron oxide by weight of the pulp; the filler is calcium carbonate with a particle size of 15 μm; the oven-dry weight ratio of fiber, latex, additives, and filler is 25:12:3:70.

[0105] (4) Add 0.3% polyacrylamide by oven-dry weight of the slurry to the slurry obtained in step (3), and then use a slurry pump to shear the slurry to obtain micro-flocs; wherein the molecular weight of the polyacrylamide is 2 million.

[0106] (5) Add an inorganic microparticle solution modified with a coupling agent of 1.5% of the oven-dry weight of the slurry to the microflocs obtained in step (4), and perform slurry flow in a headbox. Then, perform mesh forming, pressing, drying and vulcanization in sequence to obtain fiber sealing material. The vulcanization temperature is 180°C and the vulcanization time is 5 min.

[0107] The fiber sealing material prepared in Example 2 was cut into gaskets and installed on the flange. After being placed in an oven at 120°C for 22 hours, it was taken out, dried to room temperature, and the flange was opened with a torque measuring instrument. The peeling force was 0N (i.e., it could be peeled off without applying external force).

[0108] Two-component room temperature vulcanizing silicone liquid was directly printed on the surface of the fiber sealing material prepared in Example 2. After the adhesive line cured, photos of the adhesive line after scraping it by hand and after scratching it with a fingernail are shown below. Figure 2 As shown.

[0109] from Figure 2 As can be seen, the adhesive thread adheres very firmly to the fiber sealing material, and the adhesive thread will not crack or fall off.

[0110] Example 3

[0111] A method for preparing a fiber sealing material includes the following steps:

[0112] (1) Add water to a dispersion tank, turn on mechanical stirring at 1200 rpm, add γ-(methacryloyloxy)propyltriethoxysilane, continue stirring for 5 min after addition, then add microfibrillated cellulose, stir at 1200 rpm for 20 min to obtain a coupling agent modified microfibrillated cellulose solution with a solid content of 3%; wherein, the mass of γ-(methacryloyloxy)propyltriethoxysilane is 50% of the mass of microfibrillated cellulose; microfibrillated cellulose is obtained by mechanically highly finely fibrillating plant fiber hardwood chemical pulp fiber; the diameter of microfibrillated cellulose is 60 nm and the aspect ratio is 2000;

[0113] (2) Add water to the dispersion tank, turn on the mechanical stirrer at 1500 rpm, add methyltrimethoxysilane D20, continue stirring for 5 min after the addition, then add submicron bentonite, stir at 1500 rpm for 20 min to obtain a coupling agent modified inorganic microparticle solution with a solid content of 12%; wherein, the mass of methyltrimethoxysilane D20 is 30% of the mass of bentonite; the particle size of bentonite is 500 nm, produced by Hebei Yuteng Mineral Products Processing Plant;

[0114] (3) Add fiber and water to a dispersion tank and dissolve for 50 min to achieve a dissolution concentration of 5%. Then add 6% (by weight of fiber) microfibrillated cellulose and dissolve for 15 min. Next, add latex, additives, and fillers and dissolve for 30 min. Finally, add 0.5% (by weight of fiber) of a coupling agent-modified microfibrillated cellulose solution and dissolve for 10 min to obtain the pulp. The fibers are coniferous chemical pulp fiber, sepiolite fiber, and carbon fiber, with a mass ratio of 8:1:1. The coniferous chemical pulp fiber has a length of 4 mm and a width of 30 μm. The sepiolite fiber has a length of 3 mm and a width of 25 μm. The carbon fiber has a length of 3 mm and a width of 10 μm. The microfibrillated cellulose is derived from plant fibers. The chemical pulp fiber of Fiberia conifera is obtained by mechanically highly fine fiberization; the diameter of the microfibrillated cellulose is 150 nm and the aspect ratio is 300; the latex is styrene-butadiene latex and chloroprene latex in a mass ratio of 1:1, the solid content of the latex is 50%; the viscosity of the latex is 50 cP; the additives are 0.8% sulfur by mass of pulp, 0.7% thiuram-based accelerator TMTM by mass of pulp, 0.5% zinc oxide by mass of pulp, 0.9% 2,6-di-tert-butyl-p-cresol by mass of pulp, and 0.3% organic pigment Permanent Yellow (Shandong Jinboyu Pigment Co., Ltd.) by mass of pulp; the filler is calcined clay (Shanxi Jinyang Minerals) with a particle size of 15 μm; the oven-dry mass ratio of fiber, latex, additives and filler is 30:20:6:44;

[0115] (4) Add 0.3% polyacrylamide by oven-dry weight of the slurry to the slurry obtained in step (3), and then use a slurry pump to shear the slurry to obtain micro-flocs; wherein the molecular weight of the polyacrylamide is 3 million.

[0116] (5) Add an inorganic microparticle solution modified with a coupling agent of 1% of the oven-dry weight of the slurry to the microflocs obtained in step (4), and perform slurry flow in a headbox. Then, perform mesh forming, pressing, drying and vulcanization in sequence to obtain fiber sealing material. The vulcanization temperature is 160°C and the vulcanization time is 10 min.

[0117] The fiber sealing material prepared in Example 3 was cut into gaskets and installed on the flange. After being placed in an oven at 120°C for 22 hours, it was taken out, dried to room temperature, and then the flange was opened with a torque meter. The peeling force was 0N (i.e., it could be peeled off without applying external force).

[0118] Two-component room temperature vulcanizing silicone liquid was directly printed on the surface of the fiber sealing material prepared in Example 3. After the adhesive line cured, photos of the adhesive line after scraping it by hand and after scratching it with a fingernail are shown below. Figure 3 As shown.

[0119] from Figure 3 As can be seen, the adhesive thread adheres very firmly to the fiber sealing material, and the adhesive thread will not crack or fall off.

[0120] Example 4

[0121] A method for preparing a fiber sealing material includes the following steps:

[0122] (1) Add water to a dispersion tank, turn on mechanical stirring at 600 rpm, add γ-(2,3-epoxypropoxy)propyltrimethoxysilane, continue stirring for 25 min after addition, then add microfibrillated cellulose, stir at 600 rpm for 80 min to obtain a coupling agent modified microfibrillated cellulose solution with a solid content of 6%; wherein, the mass of γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 30% of the mass of microfibrillated cellulose; microfibrillated cellulose is obtained by mechanically highly finely fibrillating plant fiber hardwood chemical pulp fiber; the diameter of microfibrillated cellulose is 70 nm and the aspect ratio is 6500;

[0123] (2) Add water to the dispersion tank, turn on the mechanical stirring at 2000 rpm, add polyethyl silicate Si28, and continue stirring for 15 min after the addition is complete. Then add submicron bentonite, stir at 2000 rpm for 30 min to obtain a coupling agent modified inorganic microparticle solution with a solid content of 8%. The mass of polyethyl silicate Si28 is 100% of the mass of bentonite. The particle size of bentonite is 500 nm and it is produced by Hebei Yuteng Mineral Products Processing Plant.

[0124] (3) Add fiber and water to a dispersion tank and dissolve for 50 min to achieve a dissolution concentration of 3.5%. Then add 1% (by weight of fiber) of microfibrillated cellulose and dissolve for 12 min. Next, add latex, additives, and fillers and dissolve for 50 min. Finally, add 7% (by weight of fiber) of a coupling agent-modified microfibrillated cellulose solution and dissolve for 10 min to obtain a slurry. The fibers are hemp pulp fiber, aramid fiber, and carbon fiber, with a mass ratio of 8.5:1:0.5. The hemp pulp fiber has a length of 2 mm and a width of 20 μm. The aramid fiber has a length of 5 mm and a width of 25 μm. The carbon fiber has a length of 3 mm and a width of 25 μm. The particle size is 10 μm; microfibrillated cellulose is obtained by mechanically highly finely fibrillating plant fiber coniferous chemical pulp fiber; the diameter of microfibrillated cellulose is 30 nm, and the aspect ratio is 15000; the latex is nitrile latex, and the solid content of the latex is 43%; the viscosity of the latex is 60 cP; the additives are 1.5% sulfur by weight of pulp, 0.6% dithiophosphate ZBTP by weight of pulp, 0.3% zinc oxide by weight of pulp, 0.5% styrene diphenylamine by weight of pulp, and 1% carbon black by weight of pulp; the filler is wollastonite with a particle size of 20 μm; the oven-dry mass ratio of fiber, latex, additives and filler is 30:15:6:49;

[0125] (4) Add 0.2% polyacrylamide by oven-dry weight of the slurry to the slurry obtained in step (3), and then use a slurry pump to shear the slurry to obtain micro-flocs; wherein the molecular weight of the polyacrylamide is 4 million.

[0126] (5) Add an inorganic microparticle solution modified with a coupling agent of 0.7% of the oven-dry weight of the slurry to the microflocs obtained in step (4), and perform slurry flow in a headbox. Then, perform mesh forming, pressing, drying and vulcanization in sequence to obtain fiber sealing material. The vulcanization temperature is 160°C and the vulcanization time is 10 min.

[0127] The fiber sealing material prepared in Example 4 was cut into gaskets and installed on the flange. After being placed in an oven at 120°C for 22 hours, it was taken out, dried to room temperature, and the flange was opened with a torque measuring instrument. The peeling force was 0N (i.e., it could be peeled off without applying external force).

[0128] Two-component room temperature vulcanizing silicone liquid was directly printed on the surface of the fiber sealing material prepared in Example 4. After the adhesive line cured, photos of the adhesive line after scraping it by hand and after scratching it with a fingernail are shown below. Figure 4 As shown.

[0129] from Figure 4 As can be seen, the adhesive thread adheres very firmly to the fiber sealing material, and the adhesive thread will not crack or fall off.

[0130] Example 5

[0131] A method for preparing a fiber sealing material includes the following steps:

[0132] (1) Add water to a dispersion tank, turn on mechanical stirring at 1000 rpm, add 3-aminopropyltriethoxysilane, continue stirring for 15 min after addition, then add microfibrillated cellulose, stir at 1000 rpm for 60 min to obtain a coupling agent modified microfibrillated cellulose solution with a solid content of 2.8%; wherein, the mass of 3-aminopropyltriethoxysilane is 80% of the mass of microfibrillated cellulose; microfibrillated cellulose is obtained by mechanically highly finely fibrillating plant fiber hemp pulp fiber; the diameter of microfibrillated cellulose is 150 nm and the aspect ratio is 5000;

[0133] (2) Add water to the dispersion tank, turn on the mechanical stirrer at 1000 rpm, add methyltrimethoxysilane D20, continue stirring for 20 min after the addition, then add submicron-sized bentonite, stir at 1000 rpm for 60 min to obtain a coupling agent modified inorganic microparticle solution with a solid content of 6.5%; wherein, the mass of methyltrimethoxysilane D20 is 30% of the mass of bentonite; the particle size of bentonite is 500 nm, produced by Hebei Yuteng Mineral Products Processing Plant;

[0134] (3) Fiber and water were added to a dispersion tank and dissolved for 45 minutes to achieve a dissolution concentration of 3.5%. Then, 3.5% (by weight of fiber) of microfibrillated cellulose was added and dissolved for 12 minutes. Latex, additives, and fillers were then added and dissolved for 50 minutes. Subsequently, 5.5% (by weight of fiber) of a coupling agent-modified microfibrillated cellulose solution was added and dissolved for 12 minutes to obtain the pulp. The fibers consisted of coniferous chemical pulp fiber, aramid fiber, carbon fiber, and ceramic fiber. The coniferous chemical pulp fiber had a length of 3.5 mm and a width of 30 μm; the aramid fiber had a length of 5 mm and a width of 25 μm; the carbon fiber had a length of 3 mm and a width of 10 μm; and the ceramic fiber had a length of 5 mm and a width of 10 μm. The coniferous chemical pulp fiber and aramid fiber... The mass ratio of fiber, carbon fiber, and ceramic fiber is 7:1.5:0.5:1; microfibrillated cellulose is obtained by mechanically highly finely fibrillating plant fiber coniferous chemical pulp fiber; the diameter of microfibrillated cellulose is 180nm, and the aspect ratio is 3500; the latex is nitrile latex with a solid content of 43% and a viscosity of 60cP; the additives are 1% sulfur by weight of the pulp, 0.5% dithiophosphate ZBTP by weight of the pulp, 0.2% zinc oxide by weight of the pulp, 0.6% styrene diphenylamine by weight of the pulp, and 1.2% carbon black by weight of the pulp; the filler is kaolin (Guangdong Maoming Kaolin Technology) with a particle size of 10μm; the oven-dry mass ratio of fiber, latex, additives, and filler is 30:15:7:48;

[0135] (4) Add 0.4% polyacrylamide by oven-dry weight of the slurry to the slurry obtained in step (3), and then use a slurry pump to shear it to obtain micro-flocs; wherein the molecular weight of polyacrylamide is 2 million.

[0136] (5) Add an inorganic microparticle solution modified with a coupling agent of 1.6% of the oven-dry weight of the slurry to the microflocs obtained in step (4), and perform slurry flow in a headbox. Then, perform mesh forming, pressing, drying and vulcanization in sequence to obtain fiber sealing material. The vulcanization temperature is 160°C and the vulcanization time is 10 min.

[0137] The fiber sealing material prepared in Example 5 was cut into gaskets and installed on the flange. After being placed in an oven at 120°C for 22 hours, it was taken out, dried to room temperature, and the flange was opened with a torque measuring instrument. The peeling force was 0N (i.e., it could be peeled off without applying external force).

[0138] Two-component room temperature vulcanizing silicone liquid was directly printed on the surface of the fiber sealing material prepared in Example 5. After the adhesive line cured, photos of the adhesive line after scraping it by hand and after scratching it with a fingernail are shown below. Figure 5 As shown.

[0139] from Figure 5 As can be seen, the adhesive thread adheres very firmly to the fiber sealing material, and the adhesive thread will not crack or fall off.

[0140] Comparative Example 1

[0141] Traditional method for preparing fiber sealing material: The pulp composition ratio is as follows: 20wt% softwood chemical pulp fiber, 5wt% aramid fiber, 4wt% glass fiber, 16wt% styrene-butadiene latex, 20wt% talc, and 35wt% calcined clay; the additives are 0.7% sulfur, 0.6% dithiophosphate accelerator ZBTP, 0.3% zinc oxide, 0.5% styrene diphenylamine, and 1.2% carbon black by weight of pulp. Add an appropriate amount of water to a dispersion tank, add the above raw materials under stirring, disperse for 80 minutes, and then form the mixed pulp into paper. After wire forming, wet pressing, drying, and vulcanization, the sealing material is obtained.

[0142] The fiber sealing material prepared in Comparative Example 1 was cut into gaskets and installed on the flange. After being placed in an oven at 120°C for 22 hours, it was taken out, dried to room temperature, and the flange was opened with a torque measuring instrument. The peeling force was 2950 N.

[0143] Two-component room temperature vulcanizing silicone liquid was directly printed on the surface of the fiber sealing material prepared in Comparative Example 1. After the adhesive line cured, photos of the adhesive line after scraping it by hand and after scratching it with a fingernail are shown below. Figure 6 As shown.

[0144] from Figure 6It can be seen that the adhesive thread does not adhere firmly to the fiber sealing material after curing. The adhesive thread is easy to crack and fall off when scratched by hand or picked at with fingernails.

[0145] As can be seen from the examples and comparative examples, the sealant provided by the present invention can prevent the adhesive lines from cracking, falling off, and sticking to the cylinder.

[0146] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a fiber sealing material, comprising the following steps: (1) Mix the fiber, solvent, microfibrillated cellulose, latex, additives, filler and coupling agent modified microfibrillated cellulose solution to obtain slurry; (2) Mix the slurry obtained in step (1) with the flocculant, and then shear it to obtain micro-flocs; (3) The microflocs obtained in step (2) are mixed with the inorganic microparticle solution modified by coupling agent and paper is made to obtain fiber sealing material; The mixing of the fiber, solvent, microfibrillated cellulose, latex, additives, fillers, and coupling agent-modified microfibrillated cellulose solution is as follows: the fiber and solvent are mixed for a first dissolution, then microfibrillated cellulose is added for a second dissolution, then latex, additives, and fillers are added for a third dissolution, and finally coupling agent-modified microfibrillated cellulose solution is added for a fourth dissolution. The additives include at least one of vulcanizing agents, accelerators, activators, anti-aging agents, pigments, and dyes; the vulcanizing agent is sulfur; the accelerator is at least one of thiazoles, dithiophosphates, and thiurams; the activator is zinc oxide or stearic acid; the anti-aging agent is styreninated diphenylamine, p,p'-diisopropylphenyl diphenylamine, 2-thiol-methylbenzimidazole, or 2,6-di-tert-butyl-p-cresol; the pigment is carbon black or iron oxide; and the dye is an organic dye. The method for preparing the coupling agent modified microfibrillated cellulose solution is as follows: mix the coupling agent and water, and then add microfibrillated cellulose; The coupling agent in the microfibrillated cellulose solution modified with the coupling agent is at least one of 3-aminopropyltriethoxysilane, γ-(methacryloyloxy)propyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and γ-(methacryloyloxy)-propyltrimethoxysilane. The inorganic microparticles in the coupling agent modified inorganic microparticle solution in step (3) are at least one of silica, bentonite and montmorillonite; The coupling agent in the inorganic microparticle solution modified by the coupling agent is at least one of 3-aminopropyltriethoxysilane, 3-propyltrimethoxysilane, 3-propyltriethoxysilane, polyethyl silicate, methyltrimethoxysilane, and titanate coupling agents.

2. The preparation method according to claim 1, characterized in that, In step (1), the oven-dry mass ratio of fiber, latex, additives and filler is (5~40):(5~25):(2~10):(10~80).

3. The preparation method according to claim 1, characterized in that, In step (1), the diameter of the microfibrillated cellulose is 10~200nm and the aspect ratio of the microfibrillated cellulose is 100~20000.

4. The preparation method according to claim 1 or 3, characterized in that, In step (1), the mass of microfibrillated cellulose is 0.1-10% of the fiber mass.

5. The preparation method according to claim 1, characterized in that, The filler in step (1) is at least one of calcium carbonate, talc, silica, kaolin, wollastonite, mica, and calcined clay.

6. The preparation method according to claim 1, characterized in that, In step (1), the solid content of the coupling agent modified microfibrillated cellulose solution is 0.1-10%, and the mass of the coupling agent modified microfibrillated cellulose solution is 0.1-10% of the fiber mass.

7. The preparation method according to claim 1, characterized in that, In step (2), the flocculant is a cationic polymer, and the mass of the flocculant is 0.01~0.5% of the oven-dry mass of the slurry.

8. The preparation method according to claim 1, characterized in that, In step (3), the solid content of the inorganic microparticle solution modified by the coupling agent is 0.1-20%, and the mass of the inorganic microparticle solution modified by the coupling agent is 0.1-2% of the oven-dry mass of the slurry.

9. The fiber sealing material prepared by the preparation method according to any one of claims 1 to 8.

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