Preparation method of abrasive belt paper containing nano ceramic particles

Abstract

The invention relates to the technical field of grinding tool materials, in particular to a preparation method of abrasive belt paper containing nano ceramic particles, which comprises the following steps: carrying out silane coupling agent surface modification on the nano ceramic particles, carrying out high-energy ball milling and ultrasonic synergistic deagglomeration to obtain a stable dispersion liquid, mixing the stable dispersion liquid with thermosetting resin to form slurry, coating a primer treated paper base with the slurry, and drying to obtain the abrasive belt paper containing the nano ceramic particles. And realizing vertical orientation arrangement of the particles under the assistance of an external field, and finally carrying out gradient curing to obtain the product. The problems of nanoparticle aggregation, weak interface bonding and disordered distribution can be effectively solved, the grinding efficiency and the surface precision of the abrasive belt paper are remarkably improved, and the service life of the abrasive belt paper is remarkably prolonged.

Description

Technical Field

[0001] This invention relates to the field of abrasive material preparation technology, specifically to a method for preparing abrasive belt paper containing nano-ceramic particles. Background Technology

[0002] In cutting-edge industrial fields such as high-end manufacturing, aerospace, precision optical component processing, and advanced semiconductor packaging, the requirements for surface treatment precision and efficiency have entered the sub-micron and even nanometer scales. This places higher performance demands on grinding tools, which are key consumables. Sanding belt paper, as a widely used flexible abrasive, has core performance indicators—including cutting sharpness, wear life, thermal stability, and structural integrity under high linear speed conditions—that directly determine processing efficiency and workpiece surface quality. Traditional sanding belt paper often uses micron-sized corundum, silicon carbide, or zirconium corundum as abrasives, bonded to a paper or cloth base with resin or animal glue. While it has some practicality under normal working conditions, problems such as easy abrasive grain passivation, high shedding rate, and limited heat dissipation gradually emerge when facing applications such as high-hardness alloys, ceramic matrix composites, or ultra-precision mirror polishing, limiting further improvements in grinding efficiency and surface quality.

[0003] To overcome these bottlenecks, researchers have recently attempted to introduce nano-ceramic particles (such as nano-alumina, nano-silicon carbide, and nano-boron nitride) with ultra-high hardness (Vickers hardness exceeding 2000), excellent thermal conductivity, and chemical inertness into abrasive systems, aiming to significantly improve grinding sharpness and wear resistance through nanoscale effects. However, due to their extremely large specific surface area and surface energy, nanoparticles are prone to agglomeration in conventional preparation processes, forming micron-sized secondary aggregates. This not only weakens their nanoscale properties but may also become stress concentration sources, affecting the overall structural strength. Furthermore, there are interfacial compatibility differences between nano-ceramic particles and organic binders (such as phenolic resins and epoxy resins) and cellulose paper bases. Without effective interfacial strengthening methods, the interfacial bonding strength may decrease under the thermo-mechanical coupling effect generated by high-speed friction, affecting the firm adhesion of the abrasive particles.

[0004] In the prior art, patent CN107558301B proposes a method for preparing high-strength abrasive belt base paper. By optimizing the wood pulp fiber ratio and combining a multi-stage sizing process of wire section spraying and press section impregnation, the tensile strength and sizing uniformity of the paper base are effectively improved, providing a more stable carrier for subsequent coating processes. This solution has positive significance at the paper base engineering level, but its technical approach mainly focuses on improving the properties of the substrate itself and does not involve the functional design of the abrasive layer, especially not considering how to effectively integrate high-performance nano-ceramic particles into the abrasive functional layer. Therefore, it has limitations in improving grinding efficiency and durability.

[0005] Another patent, CN103231319B, discloses a heavy-duty, high-strength paper-based abrasive belt and its preparation method. Its structure includes a grinding-aiding and anti-clogging layer, a top-coating layer, abrasive particles, a base layer, a moisturizing and antistatic layer, and a matrix layer. This multi-layered composite structure enhances the overall grinding performance of the abrasive belt. While this design is innovative, its abrasive system still uses traditional micron-sized particles and fails to address key issues such as the dispersion stability, interfacial bonding, and spatial arrangement of nano-ceramic particles. Furthermore, its coating process does not demonstrate control over the enrichment or directional arrangement of nanoparticles at the grinding front, making it difficult to fully convert the high hardness and highly active surface of the nanomaterials into actual grinding efficiency.

[0006] In summary, current abrasive belt paper technology lacks a synergistic "surface modification—stabilized dispersion—interface strengthening—structural arrangement" technology chain for improving performance by introducing nano-ceramic particles. Simply mixing untreated nanoparticles into a binder and coating them onto a substrate may result in agglomerates that reduce the effective utilization of abrasive density and cause localized stress distortion during curing. Even with initial dispersion, without a chemical bridging design between the functional groups on the nanoparticle surface and the binder molecular chains, the interfacial shear strength may decrease under high-temperature friction, affecting the durable adhesion of the abrasive particles. Furthermore, existing coating processes are mostly random deposition, making it difficult to guide the nano-abrasive particles to form an ordered arrangement perpendicular to the substrate. This results in some high-hardness particles being deeply embedded within the binder, failing to effectively participate in the cutting process and causing low material utilization efficiency. Therefore, there is an urgent need to develop an abrasive belt paper preparation method that can simultaneously achieve efficient deagglomeration of nano-ceramic particles, surface functionalization modification, and the formation of a strong interfacial bond with an organic-inorganic composite matrix, while optimizing the spatial orientation within the abrasive layer, to fully unleash the application potential of nano-ceramic particles in the field of precision grinding. Summary of the Invention

[0007] This invention provides a method for preparing abrasive belt paper containing nano-ceramic particles. It aims to solve key technical problems such as severe agglomeration, weak interfacial bonding, and disordered spatial distribution of nano-ceramic particles in the abrasive layer of abrasive belt paper by constructing an integrated technical path of "surface modification - stable dispersion - interface strengthening - structural arrangement". This allows for the efficient utilization of nano-ceramic particles in the precision grinding process without significantly increasing manufacturing costs.

[0008] In a first aspect, the present invention provides a method for preparing abrasive belt paper containing nano-ceramic particles, comprising the following steps: S10: Surface modification of nano-ceramic particles with a silane coupling agent. If non-magnetic particles are selected for magnetic field orientation, a magnetic layer is applied to the particle surface or magnetic elements are doped before or during modification to obtain surface-functionalized nano-ceramic particles. The nano-ceramic particles are selected from at least one of nano-alumina, nano-silicon carbide, and nano-boron nitride, with a primary particle size of 20 to 100 nanometers. The silane coupling agent is a silane compound containing epoxy or amino functional groups, including but not limited to 3-glycidoxypropyltrimethoxysilane (KH560) and 3-aminopropyltriethoxysilane (KH550). S20: The surface-functionalized nano-ceramic particles obtained after S10 treatment are mixed with an organic solvent and a dispersant, and deagglomeration is carried out by high-energy ball milling combined with ultrasonic assistance. First, the mixture is placed in a high-energy ball mill for ball milling, and then the resulting slurry is transferred to an ultrasonic reactor for ultrasonic treatment; or, an ultrasonic probe is integrated into the ball milling jar, and ultrasound is applied simultaneously during ball milling to obtain a stable dispersion of nano-ceramic particles; the organic solvent is at least one of ethanol, isopropanol, and butanone; the dispersant is at least one of sodium polyacrylate, polyvinylpyrrolidone, and trisodium citrate, and its addition amount is 0.5% to 3% of the mass of nano-ceramic particles; the ball-to-particle ratio of the high-energy ball mill is 5:1 to 10:1, the rotation speed is 300 to 600 rpm, and the time is 1 to 4 hours; the power of the ultrasonic assistance treatment is 200 to 800 watts, the frequency is 20 to 40 kHz, and the time is 10 to 60 minutes; S30: The stabilized dispersion of nano-ceramic particles obtained in S20 is mixed with a thermosetting resin binder prepolymer, a curing accelerator and a leveling agent are added, and the mixture is stirred evenly to form an abrasive coating slurry; the thermosetting resin binder is at least one of phenolic resin, epoxy resin, and polyurethane prepolymer, with a solid content of 40% to 70%; the curing accelerator is at least one of hexamethylenetetramine, 2-ethyl-4-methylimidazole, and triphenylphosphine, with an addition amount of 0.5% to 2% of the resin mass; the leveling agent is at least one of polydimethylsiloxane and fluorocarbon surfactant, with an addition amount of 0.05% to 0.3% of the total slurry mass; S40: The abrasive coating slurry obtained in S30 is coated onto a high-strength paper substrate treated with a primer. Then, under the assistance of a magnetic or electric field, the nano-ceramic particles are oriented to form an ordered structure perpendicular to the paper substrate. Subsequently, based on the morphology and dielectric properties of the nano-ceramic particles, oriented arrangement is performed under an external field: when the nano-ceramic particles are sheet-like and have a high dielectric constant, a DC or AC electric field of 100 to 500 volts / mm is applied; when they are rod-shaped and doped with magnetic elements or coated with a magnetic layer, a static magnetic field of 0.1 to 0.5 Tesla is applied; the application time is 30 seconds. For up to 120 seconds, the particles are oriented and aligned perpendicular to the paper base by dielectric force or magnetic torque. The high-strength paper base is long-fiber wood pulp paper with a tensile strength of not less than 80 Newtons / 15 mm, and its surface is pre-coated with a base layer. The base layer is formed by drying a phenolic resin solution with a solid content of 20% to 40% at 100 to 130 degrees Celsius for 1 to 3 minutes. The magnetic field strength used for magnetic field-assisted arrangement is 0.1 to 0.5 Tesla, and the action time is 30 to 120 seconds. If electric field assistance is used, the electric field strength is 100 to 500 volts / mm, and the action time is 30 to 120 seconds. S50: The coated semi-finished product obtained from S40 is pre-dried at 80 to 120 degrees Celsius for 5 to 15 minutes, then cured at 130 to 180 degrees Celsius for 20 to 60 minutes. After cooling, the sanding tape containing nano-ceramic particles is obtained.

[0009] According to the present invention, by modifying the surface of nano-ceramic particles with a silane coupling agent, functional groups that can chemically react with thermosetting resins are introduced onto their surface, thereby forming covalent bonds during subsequent curing and enhancing the interfacial bonding force between the nanoparticles and the binder. Through the synergistic effect of high-energy ball milling and ultrasound, the van der Waals forces between nanoparticles are effectively broken, achieving a nanoscale monodisperse state. By introducing an external field (magnetic field or electric field) during the coating process, nano-ceramic particles with anisotropic morphology or dielectric properties are guided to align orderly along a direction perpendicular to the substrate, exposing more high-hardness particles to the grinding front and increasing the effective abrasive density. By optimizing the resin system and additive ratio, the slurry is ensured to have good leveling properties and storage stability, avoiding sedimentation or phase separation during coating.

[0010] In some embodiments, in step S10, the amount of silane coupling agent is 1% to 5% of the mass of the nano-ceramic particles, the reaction conditions are stirring at 60 to 90 degrees Celsius for 2 to 6 hours, the pH value of the reaction system is controlled between 4 and 6, and after the reaction is completed, the particles are centrifuged, washed, and vacuum dried at 60 to 80 degrees Celsius for 4 to 12 hours to obtain surface-functionalized nano-ceramic particles.

[0011] In some embodiments, in step S20, the solid content of the stable dispersion of nano-ceramic particles is 10% to 30%, the absolute value of the zeta potential of the dispersed slurry is not less than 30 mV, and the particle size distribution D90 measured by dynamic light scattering is not more than 150 nm.

[0012] In some embodiments, in step S30, the mass fraction of nano-ceramic particles in the abrasive coating slurry is 15% to 40%, the mass fraction of thermosetting resin binder is 30% to 60%, and the remainder is organic solvent and additives.

[0013] In some embodiments, in step S40, the high-strength paper base has a basis weight of 120 to 250 g / m², a surface roughness Ra of 2 to 8 micrometers, and a dry film thickness of 5 to 15 micrometers for the base adhesive layer.

[0014] In some embodiments, in step S40, when the nano-ceramic particles are plate-shaped boron nitride, electric field-assisted arrangement is preferred; when they are rod-shaped or needle-shaped silicon carbide and their surface is coated with magnetic material (such as a magnetite nanolayer with a thickness of 5–20 nm) or bulk-doped with magnetic elements (such as Fe or Co), magnetic field-assisted arrangement is preferred; otherwise, if they have high dielectric anisotropy, electric field-assisted arrangement can be used. Before S10, the nano-silicon carbide particles are magnetically coated: 100 g of nano-silicon carbide is dispersed in 200 mL of ethanol, 10 mL of ferrous chloride tetrahydrate (0.1 mol / L) and 5 mL of ferric chloride hexahydrate (0.2 mol / L) are added, nitrogen is purged and stirred for 30 min, then ammonia is added dropwise to adjust the pH to 10, and the reaction is carried out at 70 degrees Celsius for 2 h. After centrifugation and washing, silicon carbide-coated iron oxide core-shell particles are obtained. When the alumina is nearly spherical, an electric field or magnetic field can be used for assisted orientation, or a combination of both. The premise of the external field-assisted orientation is that the nano-ceramic particles have the corresponding electrical or magnetic response capabilities. If the original particles do not have these capabilities, a modification step is required before or during S10 to enable them to acquire these capabilities. Specifically: for electric field orientation, the particles are required to have dielectric anisotropy or a high dielectric constant; for magnetic field orientation, the particles themselves are required to be ferromagnetic, or doped with magnetic elements, or have a magnetic coating on the surface. Near-spherical particles without significant dielectric / magnetic anisotropy are not suitable for effective orientation using a single external field.

[0015] In some embodiments, in step S50, the heating rate of the pre-drying stage is 2 to 5 degrees Celsius per minute, and the curing stage adopts a stepped heating program: first, the temperature is raised to 100 to 120 degrees Celsius at 3 to 6 degrees Celsius per minute and held for 5 to 10 minutes, then the temperature is raised to 130 to 180 degrees Celsius at 2 to 4 degrees Celsius per minute and held for 20 to 60 minutes. The curing temperature range of 130–180 degrees Celsius is applicable to phenolic resin, epoxy resin and polyurethane prepolymer systems, wherein phenolic resin is preferably 150–170 degrees Celsius, epoxy resin is preferably 130–160 degrees Celsius, and polyurethane prepolymer is preferably 140–180 degrees Celsius.

[0016] In some embodiments, the method further includes, after S50 curing, spraying a hydrophobic antistatic coating onto the surface of the sandpaper. The coating is composed of a fluorinated acrylate emulsion and nano-silica sol mixed at a mass ratio of 95:5 to 85:15, wherein the nano-silica sol has a silica particle size of 10 to 50 nanometers, a solid content of 10% to 30%, and a pH of 8 to 10. After spraying, the coating is dried at 90 to 110 degrees Celsius for 2 to 5 minutes, resulting in a dry film thickness of 1 to 3 micrometers. The nano-silica sol is commercially available Ludox® AS-40 colloidal silica (Sigma-Aldrich, silica particle size approximately 22 nm, solid content 40%, diluted with water to 20% solid content and pH adjusted to 9.0 before use); or prepared using the Stöber method: 100 mL of anhydrous ethanol, 20 mL of deionized water, and 5 mL of ammonia (25%) are mixed, and 5 mL of tetraethyl orthosilicate (TEOS) is added dropwise with stirring. The reaction is carried out at room temperature for 6... After dialysis purification, a silica sol with a particle size of 30 nm, a solid content of 15%, and a pH of 9.2 was obtained. When preparing the product using the Stöber method, the reaction temperature was controlled at 23±2 degrees Celsius, and mechanical stirring was performed at 500 rpm. Ammonia was added dropwise at a rate of 1 mL / min. After the reaction, the product was placed in a dialysis bag with a molecular weight cutoff of 10,000 Da and dialyzed in deionized water for 72 hours, changing the water every 6 hours, until the conductivity was below 50 μS / cm, resulting in a stable silica sol with a particle size of 30±5 nm, a solid content of 15±2%, and a pH of 9.2±0.3. The description of dependence on specific commercial products was deleted and replaced with "Commercially available colloidal silica can be used, which must meet the following requirements: particle size 10–50 nm, solid content 10–30%, pH 8–10, and must not contain organic stabilizers that affect coating adhesion."

[0017] In some embodiments, the nano-ceramic particles are composite nanoparticles, which are made by mechanically mixing nano-alumina and nano-silicon carbide in a mass ratio of 70:30 to 30:70 and then subjecting them to S10 to S50 treatment to balance hardness and toughness.

[0018] In some embodiments, in step S30, the thermosetting resin binder is a modified phenolic resin, which is prepared by polycondensation of phenol, formaldehyde and cashew phenol in a molar ratio of 1:1.2:0.1 to 1:1.8:0.3 under alkaline conditions, and the resulting resin has a viscosity of 200 to 800 mPa·s at 25 degrees Celsius.

[0019] In some embodiments, in step S20, the grinding balls used in the high-energy ball mill are zirconia balls with a diameter of 0.3 to 1.0 mm, and the grinding jar is made of polytetrafluoroethylene or stainless steel lined with polyurethane.

[0020] In a second aspect, the present invention provides a sanding belt containing nano-ceramic particles, which is prepared according to the sanding belt preparation method containing nano-ceramic particles described in any embodiment of the first aspect.

[0021] According to the present invention, the nano-ceramic particles in the abrasive layer of the sanding belt are in a monodisperse state without obvious agglomerates, and the orientation factor of the particles in the direction perpendicular to the paper base is not less than 0.6; the interfacial shear strength between the abrasive layer and the base layer is not less than 8 MPa at 25 degrees Celsius and not less than 5 MPa at 150 degrees Celsius; when dry grinding Inconel 718 high-temperature alloy at a linear velocity of 15 m / s, the material removal rate is not less than 0.8 cubic millimeters / minute, the surface roughness Ra is not more than 0.05 micrometers, and the continuous grinding life is not less than 3 times that of traditional micron-level sanding belts.

[0022] In some embodiments, the abrasive layer of the sandpaper has a thickness of 20 to 60 micrometers, wherein the number density of exposed nano-ceramic particles on the surface is not less than 5,000 per square millimeter.

[0023] In some embodiments, after the abrasive belt paper is stored for 30 days at a relative humidity of 80% and a temperature of 40 degrees Celsius, the abrasive layer does not blister, peel off or crack, and the antistatic surface resistivity is less than 1×10^9 (10 to the power of 9) ohms.

[0024] In some embodiments, the abrasive tape is suitable for submicron to nanometer-scale surface processing scenarios such as thinning and polishing of semiconductor packaging substrates, fine grinding of tenons for aero-engine blades, and ultra-precision grinding of optical glass lenses.

[0025] In some embodiments, the substrate of the sanding tape can be replaced with polyester film, aramid nonwoven fabric or paper-fabric composite substrate, the surface of which needs to be pretreated with plasma or corona to improve the adhesion of the base adhesive.

[0026] In some embodiments, in step S40, the coating method is blade coating, roller coating, or spray coating, the coating gap is controlled at 30 to 80 micrometers, and the coating speed is 5 to 20 meters per minute.

[0027] In some embodiments, in step S30, the abrasive coating slurry has a viscosity of 500 to 2000 mPa·s at 25 degrees Celsius and a storage stability of no less than 72 hours at 40 degrees Celsius without sedimentation or stratification.

[0028] In some embodiments, the volume fraction of the nano-ceramic particles in the abrasive layer is 20% to 50%, and its effective utilization rate (i.e., the proportion of particles participating in cutting) is not less than 70%.

[0029] In some embodiments, the surface temperature of the abrasive layer of the abrasive belt does not rise by more than 80 degrees Celsius and the thermal deformation is less than 5 micrometers during high-speed friction, exhibiting excellent thermal stability.

[0030] In some embodiments, the purity of the nano-ceramic particles used in the method is not less than 99.5%, the specific surface area is 20 to 80 square meters per gram, and the original agglomerate particle size D50 before surface treatment is 500 to 2000 nanometers. Detailed Implementation

[0031] The method for preparing abrasive belt paper containing nano-ceramic particles described in this invention involves a multi-step synergistic process. Its core lies in achieving monodispersity, high orientation, and strong interfacial bonding of nano-ceramic particles in the abrasive layer through four key steps: surface modification, dispersion stabilization, interface strengthening, and external field directional arrangement. Specifically, S10 corresponds to the surface silane coupling agent modification unit (1), S20 corresponds to the high-energy ball milling and ultrasonic deagglomeration unit (2), S30 corresponds to the abrasive slurry preparation unit (3), S40 corresponds to the coating and external field directional arrangement unit (4), and S50 corresponds to the drying and curing unit (5). The specific operating parameters of each process unit will be described in detail below to illustrate the specific implementation of this invention. Example

[0032] S10: Surface Functionalization Treatment. 100 g of alumina nanoparticles with a primary particle size of 50 nm (purity 99.8%, specific surface area 45 m² / g, initial aggregate D50 1200 nm) were added to an ethanol-water solution (ethanol to deionized water volume ratio 9:1) containing 2.5 g of 3-glycidyl etheroxypropyltrimethoxysilane (KH560) (2.5% of the nanoparticle mass). The pH of the system was adjusted to 5.0, and the mixture was stirred at 75°C for 4 hours. After the reaction, the mixture was centrifuged at 8000 rpm for 10 minutes, the supernatant was discarded, and the mixture was washed three times with anhydrous ethanol. Then, it was vacuum dried at 70°C for 8 hours to obtain surface-grafted epoxy-containing alumina nanoparticles, designated as sample A1.

[0033] S20: Preparation of stable dispersion. 30 g of sample A1, 0.6 g of polyvinylpyrrolidone (PVP, K30) (2% of the nanoparticle mass), and 70 g of anhydrous ethanol were added to a stainless steel ball mill jar lined with polytetrafluoroethylene. 150 g of zirconia grinding balls with a diameter of 0.5 mm (ball-to-particle ratio of 5:1) were placed inside the jar. The ball mill jar was placed in a planetary ball mill and milled at 450 rpm for 2 hours. The slurry was then transferred to an ultrasonic cleaning tank and ultrasonically treated for 30 minutes at a frequency of 30 kHz and a power of 500 W. The resulting dispersion had a solid content of 30%, a D90 of 135 nm, and a Zeta potential of -35 mV, as determined by dynamic light scattering. This dispersion is designated as dispersion B1.

[0034] S30: Preparation of abrasive coating slurry. Take 50 g of phenolic resin prepolymer (60% solids content, viscosity 500 mPa·s at 25°C), 40 g of dispersion B1, 0.8 g of hexamethylenetetramine (1.6% of resin mass), and 0.03 g of polydimethylsiloxane leveling agent (0.075% of total slurry mass). Stir in a high-speed disperser at 1500 rpm for 30 minutes to form a homogeneous slurry C1. Slurry C1 has a viscosity of 1200 mPa·s at 25°C and shows no sedimentation or stratification after standing at 40°C for 72 hours.

[0035] S40: Coating and Orientation. Long-fiber wood pulp paper with a basis weight of 180 g / m², a tensile strength of 95 N / 15 mm, and a surface roughness Ra of 5 μm was selected as the substrate (6). A base coat was pre-coated on its surface: a phenolic resin solution with a solid content of 30% was coated by a doctor blade, the dry film thickness was controlled at 10 μm, and the base coat was formed after drying at 120°C for 2 minutes (7). The pulp C1 was uniformly coated onto the base coat (7) through a doctor blade coating head (8) with a gap of 50 μm, and the coating speed was 12 m / min. Immediately after coating, the paper entered the magnetic field arrangement area (9) and a constant magnetic field of 0.3 Tesla was applied for 60 seconds to orient the nano-alumina particles in a direction perpendicular to the paper base.

[0036] S50: Drying and Curing. The coated semi-finished product is placed in a hot air circulating oven and heated to 100 degrees Celsius at a rate of 3 degrees Celsius / minute, and held at this temperature for 8 minutes for pre-drying; then the temperature is further increased to 160 degrees Celsius at a rate of 3 degrees Celsius / minute, and held at this temperature for 40 minutes to complete curing. After cooling, it is wound up to obtain the finished sandpaper D1. The abrasive layer thickness is 45 micrometers, and the number density of exposed nanoparticles on the surface is 5800 per square millimeter. Example

[0037] S10: Take 100 g of silicon carbide nanoparticles with a primary particle size of 80 nm (purity 99.6%, specific surface area 30 m² / g, original aggregate D50 of 1500 nm), and perform surface modification with 4 g (4%) of 3-aminopropyltriethoxysilane (KH550). The reaction conditions are 85 °C, pH=5.5, and reaction time of 5 hours. The post-treatment is the same as in Example 1, and sample A2 is obtained.

[0038] S20: Place 25g of sample A2, 0.5g of trisodium citrate (2%), 75g of isopropanol, and 200g of zirconia grinding balls (ball-to-material ratio 8:1) in a ball mill jar, and ball mill at 500 rpm for 3 hours. Then sonicate at 40 kHz and 600 W for 30 minutes to obtain dispersion B2 (solid content 25%, D90=140 nm, Zeta potential=-32 mV).

[0039] S30: 45g of modified phenolic resin (polymerized from phenol, formaldehyde, and cashew phenol in a molar ratio of 1:1.5:0.2, with a viscosity of 650 mPa·s at 25°C and a solid content of 65%), 45g of dispersion B2, 0.7g (1.5%) of 2-ethyl-4-methylimidazole, and 0.04g (0.08%) of fluorocarbon surfactant were stirred to obtain slurry C2 (viscosity 1500 mPa·s).

[0040] S40: The substrate is the same as in Example 1, with a dry film thickness of 12 micrometers for the primer layer. The coating gap is 60 micrometers, and the coating speed is 15 meters per minute. Because the nano-silicon carbide is rod-shaped, it is arranged with the aid of a magnetic field, with a magnetic field strength of 0.4 Tesla, and the application time is 90 seconds.

[0041] S50: Pre-dry at 100 degrees Celsius for 10 minutes, then cure at 110 degrees Celsius for 8 minutes, then increase to 170 degrees Celsius and cure for 50 minutes. This yields finished product D2. Example

[0042] S10: Take 100 g of nano boron nitride (flake-shaped, primary particle size 40 nm, purity 99.7%, specific surface area 50 m² / g), modify it with 3 g (3%) of KH560, react at 70 degrees Celsius, pH=4.5 for 3 hours to obtain sample A3.

[0043] S20: Sample A3 35 g, sodium polyacrylate 0.7 g (2%), methyl ethyl ketone 65 g, grinding balls 300 g (ball-to-material ratio 8.5:1), ball milled at 400 rpm for 2.5 hours, and ultrasonicated at 20 kHz and 400 W for 40 minutes to obtain dispersion B3 (solid content 30%, D90=130 nm, Zeta potential=-38 mV).

[0044] S30: 55 g of epoxy resin prepolymer (50% solid content), 35 g of dispersion B3, 0.9 g (1.8%) of triphenylphosphine, and 0.05 g (0.1%) of polydimethylsiloxane, to obtain slurry C3.

[0045] S40: Because boron nitride is in sheet form and has a high dielectric constant, it is arranged with the aid of an electric field, with an electric field strength of 300 volts / mm and an application time of 60 seconds.

[0046] S50: After curing, spray a mixture of fluorinated acrylate emulsion and nano-silica sol (mass ratio 90:10) onto the surface, and dry at 95 degrees Celsius for 3 minutes to form a 2-micron hydrophobic and antistatic coating. This yields the finished product D3. Example

[0047] S10 to S50 are basically the same as in Example 1, but the nano-ceramic particles are made by mechanically mixing nano-alumina and nano-silicon carbide at a mass ratio of 50:50, and then performing surface modification and subsequent treatment together. The resulting product is D4.

[0048] Comparative Example 1 Except for step S10, which omits the silane coupling agent treatment, the remaining steps are the same as in Example 1. That is, unmodified nano-alumina is directly used for dispersion and coating.

[0049] Comparative Example 2 Except for step S40, which involves no external field and natural drying and arrangement, the remaining steps are the same as in Example 1.

[0050] Comparative Example 3 Except for step S20, which only uses ordinary stirring and dispersion (1000 rpm, 30 minutes) and does not involve ball milling and ultrasonic treatment, the other steps are the same as in Example 1.

[0051] The sandpaper obtained in the above embodiments and comparative examples was subjected to performance tests, and the results are shown in the table below:

[0052] As shown in the table above, the abrasive paper obtained in the embodiments of the present invention is significantly superior to the comparative examples in terms of nanoparticle orientation, interfacial bonding strength, grinding performance, and lifespan. Comparative Example 1 has weak interfacial bonding due to lack of surface modification; Comparative Example 2 has low effective abrasive density due to lack of external field orientation; and Comparative Example 3 has severe agglomeration due to insufficient dispersion, resulting in performance degradation.

Claims

1. A method for preparing abrasive belt paper containing nano-ceramic particles, characterized in that, Includes the following steps: S10: Surface-modified nano-ceramic particles are subjected to surface silane coupling agent modification treatment to obtain surface-functionalized nano-ceramic particles; the nano-ceramic particles are selected from at least one of nano-alumina, nano-silicon carbide, and nano-boron nitride, and their primary particle size is 20 to 100 nanometers; the silane coupling agent is a silane compound containing epoxy or amino functional groups. S20: The surface-functionalized nano-ceramic particles obtained by S10 treatment are mixed with organic solvent and dispersant, and deagglomeration is carried out by high-energy ball milling combined with ultrasonic assistance to obtain a stable dispersion of nano-ceramic particles. S30: The stable dispersion of nano-ceramic particles obtained in S20 is mixed with the thermosetting resin binder prepolymer, a curing accelerator and a leveling agent are added, and the mixture is stirred evenly to form an abrasive coating slurry; S40: The abrasive coating slurry obtained in S30 is coated onto a high-strength paper substrate treated with a primer. For surface-functionalized nano-ceramic particles that have been magnetically coated or have dielectric anisotropy, a directional arrangement process is then performed under the assistance of a magnetic field of 0.1-0.5T or an electric field of 100-500V / mm, so that the nano-ceramic particles form an ordered orientation structure perpendicular to the paper substrate. If the nano-ceramic particles are magnetically coated, a magnetic field of 0.1-0.5T is applied; if the particles are sheet-like anisotropic particles, an electric field of 100-500V / mm is applied. S50: The coated semi-finished product obtained from S40 is pre-dried at 80 to 120 degrees Celsius for 5 to 15 minutes, then cured at 130 to 180 degrees Celsius for 20 to 60 minutes. After cooling, the sanding tape containing nano-ceramic particles is obtained.

2. The method for preparing abrasive belt paper containing nano-ceramic particles according to claim 1, characterized in that, In step S10, the amount of silane coupling agent is 1% to 5% of the mass of the nano-ceramic particles. The reaction conditions are stirring at 60 to 90 degrees Celsius for 2 to 6 hours, and the pH value of the reaction system is controlled between 4 and 6. After the reaction is completed, the particles are centrifuged, washed, and vacuum dried at 60 to 80 degrees Celsius for 4 to 12 hours to obtain surface-functionalized nano-ceramic particles.

3. The method for preparing abrasive belt paper containing nano-ceramic particles according to claim 1, characterized in that, In step S20, the organic solvent is at least one of ethanol, isopropanol, and methyl ethyl ketone; the dispersant is at least one of sodium polyacrylate, polyvinylpyrrolidone, and trisodium citrate, and its addition amount is 0.5% to 3% of the mass of the nano-ceramic particles; the ball-to-material ratio of the high-energy ball mill is 5:1 to 10:1, the rotation speed is 300 to 600 rpm, and the time is 1 to 4 hours; the power of the ultrasonic-assisted treatment is 200 to 800 watts, the frequency is 20 to 40 kHz, and the time is 10 to 60 minutes.

4. The method for preparing abrasive belt paper containing nano-ceramic particles according to claim 1, characterized in that, In step S30, the thermosetting resin binder is at least one of phenolic resin, epoxy resin, and polyurethane prepolymer, with a solid content of 40% to 70%; the curing accelerator is at least one of hexamethylenetetramine, 2-ethyl-4-methylimidazole, and triphenylphosphine, with an addition amount of 0.5% to 2% of the resin mass; and the leveling agent is at least one of polydimethylsiloxane and fluorocarbon surfactant, with an addition amount of 0.05% to 0.3% of the total slurry mass.

5. The method for preparing abrasive belt paper containing nano-ceramic particles according to claim 1, characterized in that, In step S40, the high-strength paper base is long-fiber wood pulp paper with a tensile strength of not less than 80 Newtons / 15 mm, a basis weight of 120 to 250 g / m², and a surface roughness Ra of 2 to 8 micrometers; the base layer is formed by drying a phenolic resin solution with a solid content of 20% to 40% at 100 to 130 degrees Celsius for 1 to 3 minutes, and the dry film thickness is 5 to 15 micrometers.

6. The method for preparing abrasive belt paper containing nano-ceramic particles according to claim 1, characterized in that, In step S40, the magnetic field strength used for magnetic field-assisted arrangement is 0.1 to 0.5 Tesla, and the application time is 30 to 120 seconds; the electric field strength used for electric field-assisted arrangement is 100 to 500 volts / mm, and the application time is 30 to 120 seconds.

7. The method for preparing abrasive belt paper containing nano-ceramic particles according to claim 1, characterized in that, In step S50, the heating rate in the pre-drying stage is 2 to 5 degrees Celsius per minute, and the curing stage adopts a stepped heating program: first, the temperature is raised to 100 to 120 degrees Celsius at 3 to 6 degrees Celsius per minute and held for 5 to 10 minutes, then the temperature is raised to 130 to 180 degrees Celsius at 2 to 4 degrees Celsius per minute and held for 20 to 60 minutes.

8. The method for preparing abrasive belt paper containing nano-ceramic particles according to claim 1, characterized in that, The method further includes spraying a hydrophobic and antistatic coating onto the surface of the sandpaper after S50 curing. The coating is made by mixing fluorinated acrylate emulsion and nano silica sol in a mass ratio of 95:5 to 85:

15. After spraying, the coating is dried at 90 to 110 degrees Celsius for 2 to 5 minutes, and the dry film thickness is 1 to 3 micrometers.

9. A sanding tape containing nano-ceramic particles, characterized in that, The abrasive belt paper includes a paper base, a base adhesive layer, and an abrasive layer. The orientation factor of the nano-ceramic particles in the abrasive layer in the direction perpendicular to the paper base is not less than 0.6, and the abrasive belt paper is prepared by the method described in any one of claims 1 to 8.

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