Epoxy resin-based porous fluororubber polishing pad and method for preparing the same

Abstract

The present application relates to a kind of epoxy resin-based porous fluororubber polishing pad and its preparation method, belong to polymer material technical field, and polishing pad includes EF-BFKM, 3,4-epoxy cyclohexylmethyl-3,4-epoxy cyclohexylmethyl carboxylate, fluorinated self-repairing diluent, fluorinated modified mesoporous silica microspheres, nano diamond-fluorosilane composite powder, curing agent and other components.EF-BFKM is double-end epoxy-fluorinated block fluororubber prepolymer for carboxyl-terminated fluororubber, TBAB, ECH after reaction, add double-hydroxyl perfluoropolyether, PFHEA, DBTDL reaction, add DEA reaction, add antioxidant 1076 and obtain.The fluorinated self-repairing diluent is 2-perfluorooctyl ethanol, PTSA after reaction, add HQ, TPAL reaction, add ADH reaction and obtain.Multiple-component synergy and process optimization, realize the comprehensive promotion of ultra-precision polishing, high durability, strong environmental adaptability and processing consistency.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to an epoxy resin-based porous fluororubber polishing pad and its preparation method. Background Technology

[0002] Polishing pads are core consumables in chemical mechanical polishing (CMP) processes, directly determining the surface flatness and processing accuracy of precision components such as wafers, optical glass, and sapphire substrates. Their performance must balance high elasticity, wear resistance, polishing slurry carrying capacity, and debris removal efficiency. Among various polishing pad substrates, rubber materials have become the mainstream choice for medium-to-high precision polishing due to their controllable elastic modulus and good workpiece fit. Traditional products are mainly made of polyurethane rubber, silicone rubber, and nitrile rubber, widely used in semiconductor chip packaging, optical device processing, and other applications.

[0003] Traditional rubber polishing pads are mostly manufactured using compression molding processes, with polishing performance controlled by adjusting the degree of crosslinking and porosity of the rubber. Polyurethane polishing pads, with their porous structure, can store polishing fluid and channel abrasive debris, achieving a surface roughness controllable between Ra 0.1μm and 0.5μm, making them dominant in global planarization polishing of silicon wafers. Silicone rubber polishing pads, on the other hand, are suitable for high-precision polishing of optical glass due to their excellent resistance to high and low temperatures and superior chemical stability. However, these types of rubber polishing pads have significant drawbacks: polyurethane polishing pads have high hardness and poor elastic recovery, easily causing scratches on the workpiece surface; silicone rubber polishing pads have insufficient wear resistance, with a service life only 1 / 3 to 1 / 2 that of polyurethane polishing pads. Furthermore, traditional rubber substrates have poor compatibility with polishing fluids, easily leading to swelling and aging, further reducing polishing accuracy and consistency.

[0004] Therefore, it is necessary to develop superior polymer materials to meet the high performance requirements of polishing pads. On the one hand, it is necessary to achieve ultra-precision polishing with nanoscale surface roughness (Ra≤0.05μm); on the other hand, it is necessary to improve the polishing pad's resistance to compression set and chemical stability to adapt to strong acid and strong alkaline polishing fluid systems, thereby improving service life and polishing accuracy and consistency. Summary of the Invention

[0005] To address the problems of existing rubber polishing pads, such as poor elastic recovery leading to workpiece scratches, insufficient wear resistance, poor compatibility with polishing fluids causing swelling and aging resulting in reduced polishing precision and consistency, and difficulty in achieving nanoscale ultra-precision polishing, this invention provides an epoxy resin-based porous fluororubber polishing pad and its preparation method. Through the synergistic effect and process optimization of multiple components including EF-BFKM, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, fluorinated self-healing diluent, fluorinated modified mesoporous silica microspheres, PFHTES, hexacarbon perfluoropolyether siloxane, nanodiamond-fluorosilane composite powder, and curing agent, a comprehensive improvement in ultra-precision polishing, high durability, strong environmental adaptability, and batch processing consistency is achieved. The specific technical solution is as follows:

[0006] An epoxy resin-based porous fluororubber polishing pad is prepared from the following raw materials in parts by weight: 55-65 parts EF-BFKM, 20-25 parts 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 5-8 parts fluorinated self-healing diluent, 4-6 parts fluorinated modified mesoporous silica microspheres, 5-7 parts curing agent, 1.2-1.8 parts PFHTES, 1.0-1.5 parts hexacarbon perfluoropolyether siloxane, 3-5 parts nano-diamond-fluorosilane composite powder, and 2-4 parts perfluoropolyether lubricant; The curing agent comprises 2-ethyl-4-methylimidazolium and 4,4-hexafluoroisopropylphthalic anhydride in a mass ratio of 1:(2.5-3.5). The EF-BFKM is a prepolymer of double-ended epoxy-fluorinated block fluororubber. It is prepared by reacting carboxyl-terminated fluororubber, TBAB, and ECH in NMP, adding dihydroxy perfluoropolyether, PFHEA, and DBTDL, adding DEA, adding antioxidant 1076, stirring to obtain a reaction solution, and then precipitating, washing, drying, and pulverizing it. The mass ratio of carboxyl-terminated fluororubber:TBAB:ECH:dihydroxy perfluoropolyether:PFHEA:DBTDL:DEA:antioxidant 1076 is (100~120):(4.0~4.5):(25~30):(30~40):(20~25):(0.5~0.8):(5~8):(0.8~1.0). The fluorinated self-healing diluent is prepared by reacting 2-perfluorooctylethanol and PTSA in ethanol, adding HQ and TPAL, adding ADH, distilling under reduced pressure, washing, and drying; the mass ratio of 2-perfluorooctylethanol:PTSA:HQ:TPAL:ADH is (35-45):(1.0-1.5):(0.3-0.5):(16-20):(22-28). The fluorinated modified mesoporous silica microspheres are prepared by modifying mesoporous silica microspheres with PFHTES. The nanodiamond-fluorosilane composite powder is prepared by hydroxylating nanodiamond powder in ethanol with concentrated nitric acid, followed by modification with PFHTES and BYK-110 in ethanol.

[0007] Furthermore, the preparation method of EF-BFKM includes the following steps: Under nitrogen protection, 100-120 parts by mass of terminal carboxyl fluororubber are added to 300-350 parts by mass of NMP and stirred to obtain fluororubber mother liquor. 4.0-4.5 parts of TBAB and 25-30 parts of ECH are added, and the mixture is refluxed and stirred to react. 30-40 parts of dihydroxy perfluoropolyether, 20-25 parts of PFHEA, and 0.5-0.8 parts of DBTDL are added, and the mixture is stirred to react for 6-8 hours. 5-8 parts of DEA are added, and the mixture is stirred to react. 0.8-1.0 parts of antioxidant 1076 are added, and the mixture is stirred to obtain a reaction solution. The reaction solution is added to deionized water, stirred, allowed to stand and separate into layers, the precipitate is collected, washed, vacuum dried, and pulverized to obtain EF-BFKM with a particle size between 80 and 120 mesh.

[0008] In the above preparation method of EF-BFKM, the carboxyl-terminated fluororubber and NMP are stirred at 85℃~90℃ for 1h~1.5h; after the addition of TBAB and ECH, the mixture is refluxed and stirred at 95℃~100℃ for 5h~6h; after the addition of dihydroxy perfluoropolyether, PFHEA, and DBTDL, the mixture is refluxed and stirred for 6h~8h; the DEA is added at 80℃~85℃; after the addition of DEA, the mixture is stirred and reacted for 3h~4h; the amount of deionized water used is 4 to 4.5 times the volume of the reaction liquid, and the temperature of the deionized water is 50℃~55℃; the precipitate is washed with anhydrous methanol.

[0009] Furthermore, the preparation method of the fluorinated self-healing diluent includes the following steps: by mass parts, 140-160 parts of ethanol, 35-45 parts of 2-perfluorooctylethanol, and 1.0-1.5 parts of PTSA are mixed, refluxed and stirred, 0.3-0.5 parts of HQ and 16-20 parts of TPAL are added, the mixture is stirred and reacted, 22-28 parts of ADH are added, the mixture is stirred and reacted, the mixture is distilled under reduced pressure, washed with deionized water, and dried under vacuum to obtain the fluorinated self-healing diluent.

[0010] In the above-mentioned method for preparing the fluorinated self-healing diluent, the reflux stirring is carried out at 65℃~70℃ for 1h~1.5h; after adding HQ and TPAL, the reaction is stirred for 2.5h~3.5h; the ADH is added at 45℃~55℃, and the reaction is stirred for 3.5h~4.5h after adding the ADH; and the ethanol is removed by vacuum distillation.

[0011] Furthermore, the preparation method of the fluorinated modified mesoporous silica microspheres includes the following steps: under nitrogen protection, the mesoporous silica microspheres are dispersed in anhydrous ethanol, ultrasonically treated to form a suspension; PFHTES is added, the pH is adjusted to 4-5, the mixture is refluxed and stirred, filtered, the filter cake is washed with anhydrous ethanol, and vacuum dried to obtain the fluorinated modified mesoporous silica microspheres.

[0012] In the above-mentioned method for preparing fluorinated modified mesoporous silica microspheres, the amount of anhydrous ethanol used is 8 to 10 times the mass of the mesoporous silica microspheres; the amount of PFHTES added is 10% to 15% of the mass of the mesoporous silica microspheres; and the reflux stirring is carried out at 65°C to 70°C for 4 to 6 hours.

[0013] Furthermore, the preparation method of the nanodiamond-fluorosilane composite powder includes the following steps: dispersing nanodiamond powder in anhydrous ethanol, adding concentrated nitric acid, refluxing and stirring, filtering, washing the filter cake with deionized water until neutral, vacuum drying to obtain hydroxylated nanodiamond powder, dispersing it in anhydrous ethanol, adding PFHTES, adding BYK-110, refluxing and stirring, filtering, washing the filter cake with anhydrous ethanol, vacuum drying, and pulverizing to a median particle size of 80nm to 150nm to obtain nanodiamond-fluorosilane composite powder.

[0014] In the above-mentioned method for preparing nanodiamond-fluorosilane composite powder, the concentration of concentrated nitric acid is 65wt% to 68wt%; the amount of concentrated nitric acid added is 20% to 30% of the mass of nanodiamond powder; after the concentrated nitric acid is added, the mixture is refluxed and stirred at 65℃ to 70℃ for 3 to 4 hours; the amount of PFHTES added is 8% to 12% of the mass of hydroxylated nanodiamond powder; the amount of BYK-110 added is 2% to 4% of the mass of hydroxylated nanodiamond powder; after the BYK-110 is added, the mixture is refluxed and stirred at 60℃ to 70℃ for 3 to 4 hours.

[0015] The preparation method of the above-mentioned epoxy resin-based porous fluororubber polishing pad includes the following steps: S1: According to the formula, EF-BFKM, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, and fluorinated self-healing diluent are mixed at 100℃~110℃ for 30min~40min, cooled to 60℃~70℃, fluorinated modified mesoporous silica microspheres, PFHTES, hexacarbon perfluoropolyether siloxane, and nanodiamond-fluorosilane composite powder are added, mixed evenly, and vacuum degassed. Perfluoropolyether lubricant and curing agent are added, mixed evenly, and vacuum degassed to obtain slurry; S2: Pour the slurry into the mold and cure it at 4MPa~6MPa and 70℃~80℃ for 2h~3h, at 6MPa~8MPa and 120℃~130℃ for 2.5h~3.5h, and at 1MPa~3MPa and 140℃~160℃ for 2h~3h; after cooling to room temperature, demold to obtain the rough polishing pad. S3: Vacuum treatment at 150℃~160℃ for 30min~40min, followed by thickness and leveling grinding, and plasma treatment to obtain a polishing pad.

[0016] The present invention provides an epoxy resin-based porous fluororubber polishing pad and its preparation method, which have the following beneficial effects: I. The epoxy resin-based porous fluororubber polishing pad of this invention achieves a comprehensive improvement in ultra-precision polishing, high durability, strong environmental adaptability, and batch processing consistency through multi-component synergy and process optimization. Its core advantages stem from the rigid-flexible network of fluororubber and epoxy resin, fluorinated functional fillers, a dynamic self-healing system, and a precisely controlled microstructure, overcoming the performance shortcomings of traditional polishing pads and adapting to the ultra-precision requirements of semiconductor, optical processing, and other fields.

[0017] II. The double-ended epoxy-fluorinated block fluororubber prepolymer (EF-BFKM) combines the flexible segments of fluororubber with the crosslinking stability of epoxy resin, forming an interpenetrating crosslinked network that balances the elasticity and rigidity of the polishing pad. The epoxy resin enhances the stability of the network structure, and the fluorinated segments construct a dense and smooth surface through microphase separation, laying the foundation for nanoscale polishing.

[0018] 3. In fluorinated modified mesoporous silica and nanodiamond-fluorosilane composite powders, fluorination modification improves the compatibility between the filler and the fluororubber matrix, avoiding agglomeration and protrusion; mesoporous silica optimizes the open pore structure, ensuring the efficiency of polishing fluid storage and chip removal; nanodiamond, as a wear-resistant skeleton, significantly improves the wear resistance of the polishing pad.

[0019] IV. The dynamic covalent bond breaking and recombination of acylhydrazone-aldehyde groups in the fluorinated self-healing diluent releases polishing pressure, repairs micro-damage, and avoids permanent deformation; the perfluoropolyether lubricant forms a low-friction lubricating film, reducing abrasive adhesion and interfacial wear during the polishing process; a specific ratio of curing agent ensures uniform and sufficient cross-linking reaction, avoiding excessive rigidity or insufficient flexibility.

[0020] Nitrogen protection during raw material preparation prevents oxidation and degradation; step-by-step solidification promotes full microphase separation of fluorine segments and reduces internal stress; plasma treatment precisely controls the surface micromorphology, further reducing surface energy and enhancing the fluorine protection effect; vacuum degassing and post-treatment remove residual small molecules and internal stress, improving structural density.

[0021] V. In the preparation method, the synergistic effect of step-curing and vacuum post-treatment not only achieves the complete formation of the cross-linked network, but also constructs a low surface energy surface layer through the microphase separation of fluorine segments; the combination of plasma treatment and precision grinding precisely controls the surface roughness and pore structure, ensuring flexible contact with the workpiece during polishing and reducing scratches. The fluorination design of EF-BFKM, fluorinated self-healing diluent, fluorinated modified mesoporous silica microspheres, and nanodiamond-fluorosilane composite powder, along with plasma fluorination treatment, forms a perfluorinated protective network. The strong electronegativity of fluorine atoms blocks the contact path between acidic and alkaline media and the matrix, improving chemical stability; the low surface energy characteristic reduces polishing fluid penetration and abrasive adhesion, balancing polishing precision and service life.

[0022] VI. The dynamic covalent bonds of the fluorinated self-healing diluent, in synergy with the perfluoropolyether lubricant and fluorinated modified filler, resolve the contradiction between high elasticity and high wear resistance; the mesoporous structure and low surface energy work together to ensure uniform distribution of polishing fluid and rapid removal of polishing debris, improving polishing consistency. The perfluorinated protective network and dynamic self-healing system work together to prevent the polishing pad from swelling and aging in strong acid and alkali environments, while extending its service life and ensuring the performance stability of batch processing. Detailed Implementation

[0023] The present invention will be further described below with reference to specific implementation examples, but the present invention is not limited to these embodiments.

[0024] Definitions: EF-BFKM is a double-ended epoxy-fluorinated block fluororubber prepolymer; NMP stands for N-methylpyrrolidone; TBAB stands for tetrabutylammonium bromide; ECH stands for epichlorohydrin; PFHEA is perfluorohexyl ethyl acrylate; DBTDL is dibutyltin dilaurate; DEA is diethanolamine; PTSA is p-toluenesulfonic acid; HQ stands for hydroquinone; TPAL stands for terephthalaldehyde; ADH stands for adipic dihydrazide; PFHTES is 1H,1H,2H,2H-perfluorohexyltriethoxysilane.

[0025] Example 1 An epoxy resin-based porous fluororubber polishing pad is prepared from the following raw materials in parts by weight: 60 parts EF-BFKM, 23 parts 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 6 parts fluorinated self-healing diluent, 5 parts fluorinated modified mesoporous silica microspheres, 6 parts curing agent, 1.5 parts PFHTES, 1.3 parts hexafluoropolyether siloxane, 4 parts nanodiamond-fluorosilane composite powder, and 3 parts perfluoropolyether lubricant. The curing agent comprises 2-ethyl-4-methylimidazolium and 4,4-hexafluoroisopropylphthalic anhydride in a mass ratio of 1:3.

[0026] The preparation method of EF-BFKM includes the following steps: Under nitrogen protection, 110 parts by mass of carboxyl-terminated fluororubber are added to 320 parts by mass of NMP, and stirred at 88℃ and 320 rpm for 1 h to obtain fluororubber mother liquor. At 52℃, 4.3 parts by mass of TBAB and 28 parts by mass of ECH are added, and the mixture is stirred at 480 rpm for 12 min. The mixture is then refluxed and stirred at 95℃ to 100℃ for 5.5 h to allow the ECH to open its ring and react with the carboxyl-terminated fluororubber. Subsequently, 35 parts by mass of dihydroxy perfluoropolyether, 22 parts by mass of PFHEA, and 0.6 parts by mass of DBTDL are added, and the mixture is refluxed and stirred at 520 rpm for another 7 h to perform block copolymerization. Polymerization was carried out by adding 6 parts of DEA at 80℃ to 85℃ and stirring for 3.5h to end-cap the reaction. Then, 0.9 parts of antioxidant 1076 were added and the mixture was stirred at 280rpm for 35min to obtain a reaction solution. The reaction solution was added to 4.2 times the volume of deionized water at 52℃ at a rate of 4.5L / min and stirred at 160rpm to precipitate for 3.5h. After standing and separating the layers, the precipitate was collected and washed three times with anhydrous methanol (each time the amount of methanol was 2.5 times the mass of the precipitate). The precipitate was then vacuum dried at 85℃ for 14h, pulverized, and the particle size was taken from 80 to 120 mesh to obtain a double-ended epoxy-fluorinated block fluororubber prepolymer, named EF-BFKM.

[0027] The preparation method of the fluorinated self-healing diluent includes the following steps: 150 parts by mass of ethanol, 40 parts by mass of 2-perfluorooctylethanol and 1.2 parts by mass of PTSA are mixed and refluxed at 65℃ to 70℃ for 1 hour until dissolved. 0.4 parts by mass of HQ and 18 parts by mass of TPAL are added and the mixture is stirred at 280 rpm for 3 hours to obtain an aldehyde-modified fluorinated intermediate. 25 parts by mass of ADH are added at 45℃ to 55℃ and the mixture is stirred for 4 hours. Ethanol is removed by vacuum distillation at 60℃ to 65℃. The mixture is washed twice with deionized water (each time the amount of water is 1.2 times the mass of the product). The mixture is then vacuum dried at 60℃ for 7 hours to obtain the fluorinated self-healing diluent.

[0028] The preparation method of fluorinated modified mesoporous silica microspheres includes the following steps: under nitrogen protection, the mesoporous silica microspheres are dispersed in 9 times their mass of anhydrous ethanol and ultrasonically treated for 35 min to form a suspension; 13% of the mass of the mesoporous silica microspheres of PFHTES is added, the pH is adjusted to 4.5 with acetic acid, and the mixture is refluxed and stirred in the range of 65℃ to 70℃ for 5 h. After filtration, the filter cake is washed 3 times with anhydrous ethanol and vacuum dried at 110℃ for 8 h to obtain fluorinated modified mesoporous silica microspheres.

[0029] The preparation method of nanodiamond-fluorosilane composite powder includes the following steps: Nanodiamond powder is dispersed in 9 times its mass of anhydrous ethanol, 25% (by weight of the nanodiamond powder) of concentrated nitric acid (67wt%) is added, and the mixture is refluxed and stirred at 65℃~70℃ for 3.5h to oxidize the surface by hydroxylation; the mixture is filtered, the filter cake is washed with deionized water until neutral, and vacuum dried at 85℃ to constant weight to obtain hydroxylated nanodiamond powder, which is then dispersed in 13 times its mass of anhydrous ethanol, 10% (by weight of the hydroxylated nanodiamond powder) of PFHTES and 3% (by weight of the hydroxylated nanodiamond powder) of BYK-110 are added, and the mixture is refluxed and stirred at 60℃~70℃ for 3.5h, filtered, the filter cake is washed twice with ethanol, vacuum dried at 115℃ for 7h, and then pulverized with airflow to a median particle size of 126nm to obtain nanodiamond-fluorosilane composite powder.

[0030] The preparation method of the above-mentioned epoxy resin-based porous fluororubber polishing pad includes the following steps: S1: According to the formula, weigh EF-BFKM, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, and fluorinated self-healing diluent, put them into a mixer, and mix at 105℃ for 35 minutes to obtain the base material; cool down to 65℃, add fluorinated modified mesoporous silica microspheres, PFHTES, hexacarbon perfluoropolyether siloxane, and nanodiamond-fluorosilane composite powder, mix for 30 minutes, degas under vacuum at -0.088MPa for 20 minutes, add perfluoropolyether lubricant and curing agent, mix evenly, and degas under vacuum at -0.088MPa for 8 minutes to obtain the slurry; S2: Pour the slurry into a mold with a micro-textured surface (texture height 20μm, spacing 120μm) and perform step curing: cure at 5MPa and 75℃ for 2.5h, cure at 7MPa and 125℃ for 3h, and hold at 2MPa and 150℃ for 2.5h to promote the separation of fluorine chain microphases; after cooling to room temperature, demold to obtain the rough polishing pad; S3: Vacuum treatment at 155℃ for 35 minutes to remove residual stress and small molecules; use a surface grinder to perform precision grinding on the rough polishing pad to fix the thickness and level it; then use a CF4 and O2 mixed gas with a volume ratio of 4:1 to perform plasma treatment at 200W power for 5 minutes to achieve etching and fluorination modification, so as to further fluorinate the surface and adjust the microstructure to obtain the polishing pad.

[0031] Example 2 An epoxy resin-based porous fluororubber polishing pad is prepared from the following raw materials in parts by weight: 55 parts EF-BFKM, 25 parts 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 5 parts fluorinated self-healing diluent, 6 parts fluorinated modified mesoporous silica microspheres, 5 parts curing agent, 1.8 parts PFHTES, 1.0 part hexafluoropolyether siloxane, 5 parts nanodiamond-fluorosilane composite powder, and 4 parts perfluoropolyether lubricant. The curing agent comprises 2-ethyl-4-methylimidazolium and 4,4-hexafluoroisopropylphthalic anhydride in a mass ratio of 1:2.5.

[0032] The preparation method of EF-BFKM includes the following steps: Under nitrogen protection, 100 parts by mass of carboxyl-terminated fluororubber are added to 350 parts by mass of NMP, and stirred at 85℃ and 350 rpm for 1 h to obtain a fluororubber mother liquor. At 55℃, 4.0 parts by mass of TBAB and 30 parts by mass of ECH are added, and the mixture is stirred at 450 rpm for 15 min. The mixture is then refluxed and stirred at 95℃ to 100℃ for 5 h to allow the ECH to open its ring and react with the carboxyl-terminated fluororubber. Subsequently, 40 parts by mass of dihydroxy perfluoropolyether, 20 parts by mass of PFHEA, and 0.8 parts by mass of DBTDL are added, and the mixture is refluxed and stirred at 500 rpm for another 8 h. Block copolymerization was performed. At 80℃–85℃, 5 parts of DEA were added, and the mixture was stirred for 4 hours to seal the ends. 0.8 parts of antioxidant 1076 were added, and the mixture was stirred at 300 rpm for 30 minutes to obtain a reaction solution. The reaction solution was added to 4 times its volume of 55℃ deionized water at a rate of 5 L / min, and the mixture was stirred at 150 rpm to precipitate for 4 hours. After standing and separating into layers, the precipitate was collected and washed three times with anhydrous methanol (each time the amount of methanol was 3 times the mass of the precipitate). The precipitate was then vacuum dried at 80℃ for 16 hours, pulverized, and a particle size between 80 mesh and 120 mesh was obtained to obtain a double-ended epoxy-fluorinated block fluororubber prepolymer, named EF-BFKM.

[0033] The preparation method of the fluorinated self-healing diluent includes the following steps: 160 parts by mass of ethanol, 35 parts by mass of 2-perfluorooctylethanol and 1.5 parts by mass of PTSA are mixed and refluxed at 65℃ to 70℃ for 1 hour until dissolved. 0.5 parts by mass of HQ and 16 parts by mass of TPAL are added and the mixture is stirred at 300 rpm for 2.5 hours to obtain an aldehyde-based fluorinated intermediate. 28 parts by mass of ADH are added at 45℃ to 55℃ and the mixture is stirred for 3.5 hours. Ethanol is removed by vacuum distillation at 60℃ to 65℃. The mixture is washed three times with deionized water (each time the amount of water is 1 times the mass of the product) and dried under vacuum at 65℃ for 6 hours to obtain the fluorinated self-healing diluent.

[0034] The preparation method of fluorinated modified mesoporous silica microspheres includes the following steps: under nitrogen protection, the mesoporous silica microspheres are dispersed in 8 times their mass of anhydrous ethanol and ultrasonically treated for 40 min to form a suspension; 10% of the mass of the mesoporous silica microspheres of PFHTES is added, the pH is adjusted to 5 with acetic acid, and the mixture is refluxed and stirred in the range of 65℃ to 70℃ for 4 h, filtered, the filter cake is washed 4 times with anhydrous ethanol, and vacuum dried at 100℃ for 10 h to obtain fluorinated modified mesoporous silica microspheres.

[0035] The preparation method of nanodiamond-fluorosilane composite powder includes the following steps: Nanodiamond powder is dispersed in 10 times its mass of anhydrous ethanol, 20% (by weight of the nanodiamond powder) of 68wt% concentrated nitric acid is added, and the mixture is refluxed and stirred at 65℃~70℃ for 3 hours to oxidize the surface and hydroxylate it. The mixture is then filtered, the filter cake is washed with deionized water until neutral, and vacuum dried at 90℃ to constant weight to obtain hydroxylated nanodiamond powder. This hydroxylated nanodiamond powder is then dispersed in 12 times its mass of anhydrous ethanol, 12% (by weight of the hydroxylated nanodiamond powder) of PFHTES and 2% (by weight of the hydroxylated nanodiamond powder) of BYK-110 are added, and the mixture is refluxed and stirred at 60℃~70℃ for 4 hours. The mixture is then filtered, the filter cake is washed twice with ethanol, vacuum dried at 120℃ for 6 hours, and then pulverized with an airflow to a median particle size of 150nm to obtain nanodiamond-fluorosilane composite powder.

[0036] The preparation method of the above-mentioned epoxy resin-based porous fluororubber polishing pad includes the following steps: S1: According to the formula, weigh EF-BFKM, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, and fluorinated self-healing diluent, put them into a mixer, and mix at 100℃ for 40 min to obtain the base material; cool down to 60℃, add fluorinated modified mesoporous silica microspheres, PFHTES, hexacarbon perfluoropolyether siloxane, and nanodiamond-fluorosilane composite powder, mix for 35 min, degas under vacuum at -0.09MPa for 15 min, add perfluoropolyether lubricant and curing agent, mix evenly, degas under vacuum at -0.09MPa for 5 min to obtain the slurry; S2: Pour the slurry into a mold with a micro-textured surface (texture height 30μm, spacing 150μm) and perform step curing: cure at 4MPa and 80℃ for 2h, cure at 8MPa and 120℃ for 3.5h, and hold at 1MPa and 160℃ for 2h to promote the separation of fluorine chain microphases; after cooling to room temperature, demold to obtain the rough polishing pad; S3: Vacuum treatment at 160℃ for 30 min removes residual stress and small molecules; the rough polishing pad is precision ground to fix thickness and level using a surface grinder; then plasma treatment at 200W power for 6 min is performed using a CF4 and O2 mixed gas with a volume ratio of 5:1 to achieve etching and fluorination modification, so as to further fluorinate the surface and adjust the microstructure to obtain the polishing pad.

[0037] Example 3 An epoxy resin-based porous fluororubber polishing pad is prepared from the following raw materials in parts by weight: 65 parts EF-BFKM, 20 parts 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 8 parts fluorinated self-healing diluent, 4 parts fluorinated modified mesoporous silica microspheres, 7 parts curing agent, 1.2 parts PFHTES, 1.5 parts hexafluoropolyether siloxane, 3 parts nanodiamond-fluorosilane composite powder, and 2 parts perfluoropolyether lubricant. The curing agent comprises 2-ethyl-4-methylimidazolium and 4,4-hexafluoroisopropylphthalic anhydride in a mass ratio of 1:3.5.

[0038] The preparation method of EF-BFKM includes the following steps: Under nitrogen protection, 120 parts by mass of carboxyl-terminated fluororubber are added to 300 parts by mass of NMP, and stirred at 90℃ and 300rpm for 1.5h to obtain fluororubber mother liquor. At 50℃, 4.5 parts by mass of TBAB and 25 parts by mass of ECH are added, and the mixture is stirred at 500rpm for 10min. The mixture is then refluxed and stirred at 95℃~100℃ for 6h to allow the ECH to open its ring and react with the carboxyl-terminated fluororubber. Subsequently, 30 parts by mass of dihydroxy perfluoropolyether, 25 parts by mass of PFHEA, and 0.5 parts by mass of DBTDL are added, and the mixture is refluxed and stirred at 550rpm for another 6h. Block copolymerization was performed. At 80℃–85℃, 8 parts of DEA were added, and the mixture was stirred for 3 hours to seal the ends. 1.0 part of antioxidant 1076 was added, and the mixture was stirred at 250 rpm for 40 minutes to obtain a reaction solution. The reaction solution was added to 4.5 times its volume of 50℃ deionized water at a rate of 4 L / min, and the mixture was stirred at 180 rpm for 3 hours to precipitate. After standing and separating into layers, the precipitate was collected and washed four times with anhydrous methanol (each time the amount of methanol was twice the mass of the precipitate). The precipitate was then vacuum dried at 90℃ for 12 hours, pulverized, and the particle size was measured to be between 80 mesh and 120 mesh to obtain a double-ended epoxy-fluorinated block fluororubber prepolymer, named EF-BFKM.

[0039] The preparation method of the fluorinated self-healing diluent includes the following steps: 140 parts by mass of ethanol, 45 parts by mass of 2-perfluorooctylethanol and 1.0 part by mass of PTSA are mixed and refluxed at 65℃ to 70℃ for 1.5 h until dissolved. 0.3 parts by mass of HQ and 20 parts by mass of TPAL are added and the mixture is stirred at 250 rpm for 3.5 h to obtain an aldehyde-modified fluorinated intermediate. 22 parts by mass of ADH are added at 45℃ to 55℃ and the mixture is stirred for 4.5 h. Ethanol is removed by vacuum distillation at 60℃ to 65℃. The mixture is washed twice with deionized water (each time the amount of water is 1.5 times the mass of the product). The mixture is then vacuum dried at 55℃ for 8 h to obtain the fluorinated self-healing diluent.

[0040] The preparation method of fluorinated modified mesoporous silica microspheres includes the following steps: under nitrogen protection, the mesoporous silica microspheres are dispersed in 10 times their mass of anhydrous ethanol and ultrasonically treated for 30 min to form a suspension; 15% of the mass of the mesoporous silica microspheres of PFHTES is added, the pH is adjusted to 4 with acetic acid, and the mixture is refluxed and stirred in the range of 65℃~70℃ for 6 h, filtered, the filter cake is washed 3 times with anhydrous ethanol, and vacuum dried at 120℃ for 8 h to obtain fluorinated modified mesoporous silica microspheres.

[0041] The preparation method of nanodiamond-fluorosilane composite powder includes the following steps: Nanodiamond powder is dispersed in 8 times its mass of anhydrous ethanol, 30% (by mass) of concentrated nitric acid (65wt%) is added, and the mixture is refluxed and stirred at 65℃~70℃ for 4 hours to oxidize the surface and hydroxylate it. The mixture is then filtered, the filter cake is washed with deionized water until neutral, and vacuum dried at 80℃ to constant weight to obtain hydroxylated nanodiamond powder. This hydroxylated nanodiamond powder is then dispersed in 15 times its mass of anhydrous ethanol, 8% (by mass) of PFHTES and 4% (by mass) of BYK-110 are added, and the mixture is refluxed and stirred at 60℃~70℃ for 3 hours. The mixture is then filtered, the filter cake is washed three times with ethanol, vacuum dried at 110℃ for 8 hours, and then pulverized with an airflow to a median particle size of 80nm to obtain nanodiamond-fluorosilane composite powder.

[0042] The preparation method of the above-mentioned epoxy resin-based porous fluororubber polishing pad includes the following steps: S1: According to the formula, weigh EF-BFKM, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, and fluorinated self-healing diluent, put them into a mixer, and mix at 110℃ for 30 min to obtain the base material; cool down to 70℃, add fluorinated modified mesoporous silica microspheres, PFHTES, hexacarbon perfluoropolyether siloxane, and nanodiamond-fluorosilane composite powder, mix for 40 min, degas under vacuum at -0.085MPa for 25 min, add perfluoropolyether lubricant and curing agent, mix evenly, and degas under vacuum at -0.085MPa for 10 min to obtain the slurry; S2: Pour the slurry into a mold with a micro-textured surface (texture height 10μm, spacing 50μm) and perform step curing: cure at 6MPa and 70℃ for 3h, cure at 6MPa and 130℃ for 2.5h, and hold at 3MPa and 140℃ for 3h to promote the separation of fluorine chain microphases; after cooling to room temperature, demold to obtain the rough polishing pad; S3: Vacuum treatment at 150℃ for 40 minutes to remove residual stress and small molecules; use a surface grinder to perform precision grinding on the rough polishing pad for thickness and leveling; then use a CF4 and O2 mixed gas with a volume ratio of 3:1 to perform plasma treatment at 220W power for 4 minutes to achieve etching and fluorination modification, so as to further fluorinate the surface and adjust the microstructure to obtain the polishing pad.

[0043] The raw materials and their sources involved in the above embodiments are as follows: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, ERL-4221, sourced from Nantong Xinnaxi New Materials Co., Ltd.; 2-ethyl-4-methylimidazolium with a purity of over 99%; 4,4-hexafluoroisopropylphthalic anhydride sourced from Hubei Hengjingrui Chemical Co., Ltd., with a purity of 98%; PFHTES, 1H,1H,2H,2H-perfluorohexyltriethoxysilane, sourced from Shandong Xiya Chemical Co., Ltd.; hexacarbon perfluoropolyether siloxane sourced from Henan Weitixi Chemical Technology Co., Ltd., with a purity of 98%; perfluoropolyether lubricant, DuPont Chemours Krytox GPL105, distributed by Dongguan Sanbang New Materials Technology Co., Ltd.; carboxyl-terminated fluororubber, a carboxyl-terminated liquid fluororubber sourced from Yuyao Huihong Plastics Factory; and NMP, N-methylpyrrolidone with a purity of over 99%. TBAB is tetrabutylammonium bromide, with a purity of over 99%. ECH is epichlorohydrin, with a purity of over 99%. Dihydroxy perfluoropolyether, with a molecular weight range of 500-5000, is sourced from Hubei Langbowan Biomedical Co., Ltd. PFHEA is perfluorohexylethyl acrylate, with a purity of over 98%. DBTDL is dibutyltin dilaurate, with a purity of over 99%. DEA is diethanolamine, with a purity of over 99%. Antioxidant 1076 has a purity of over 99%. 2-Perfluorooctylethanol is sourced from Hubei Xinmingtai Chemical Co., Ltd., with a purity of 98%. PTSA is p-toluenesulfonic acid, with a purity of over 99%. HQ is hydroquinone, with a purity of over 99%. TPAL is terephthalaldehyde, with a purity of over 98%. ADH is adipic acid dihydrazide, with a purity of over 99%. The mesoporous silica microspheres, with a particle size of 50nm-300nm, were sourced from Hebei Langfei Biotechnology Co., Ltd. The nanodiamond powder, with a median particle size of 80nm-100nm, was sourced from Xuzhou Jiechuang New Materials Technology Co., Ltd.

[0044] Comparative Example 1 The difference from Example 1 is that in the polishing pad raw material, EF-BFKM is replaced with 40 parts and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate is replaced with 43 parts.

[0045] Comparative Example 2 The difference from Example 1 is that no fluorinated self-healing diluent is added to the polishing pad material.

[0046] Comparative Example 3 The difference from Example 1 is that in the preparation of the fluorinated self-healing diluent, the phrase "add 25 parts of ADH and stir for 4 hours in the range of 45℃ to 55℃" is omitted, that is, no ADH reaction is added.

[0047] Comparative Example 4 The difference from Example 1 is that: in the polishing pad material, fluorinated modified mesoporous silica microspheres are directly replaced by mesoporous silica microspheres; and nanodiamond-fluorosilane composite powder is directly replaced by nanodiamond powder.

[0048] Comparative Example 5 The difference from Example 1 is that the ratio of 2-ethyl-4-methylimidazolium and 4,4-hexafluoroisopropylphthalic anhydride in the curing agent is changed to 3:1.

[0049] Comparative Example 6 The difference from Example 1 is that "holding at 150°C for 2.5 h" is omitted in S2 of the preparation method, and "vacuum treatment at 155°C for 35 min" is omitted in S3.

[0050] Comparative Example 7 The difference from Example 1 is that in the preparation of EF-BFKM, the amount of dihydroxy perfluoropolyether added is changed to 15 parts and the amount of PFHEA added is changed to 10 parts.

[0051] In the above comparative examples, except for the distinguishing techniques, the other methods and parameters are the same as in Example 1, and the surface roughness and volume porosity of the polishing pad are adjusted according to actual fluctuations.

[0052] I. Surface roughness inspection: Sample specifications: 50mm×50mm×3mm, 5 parallel samples per group.

[0053] Pre-test treatment: The sample was kept at a constant temperature and humidity of 25℃ and 50% for 24 hours.

[0054] Detection method: Atomic force microscopy (AFM) was used in tapping mode to scan a 5μm×5μm area. Four symmetrical points were selected at the center of the sample surface and 10mm from the edge, for a total of 5 sites. Each site was scanned 3 times. After removing data with a deviation >5%, the average value of a single site was taken, and the total average value (Ra, μm) of the 5 sites was finally calculated.

[0055] II. Porosity testing of open-pore volume: Sample specifications: 10mm×10mm×3mm, 5 parallel samples per group.

[0056] Pre-testing treatment: The sample was kept at a constant temperature and humidity of 25℃ and 50% for 24 hours, and then vacuum dried at 110℃ for 4 hours.

[0057] Test method: The boiling-water displacement method was used. The sample was immersed in deionized water and boiled for 30 minutes under a vacuum of -0.09 MPa. After cooling, the sample was soaked for another 24 hours. After blotting the surface moisture with filter paper, the dry weight m1 (g) and saturated wet weight m2 (g) of the sample were measured by the water displacement method, and the actual volume V (cm³) of the sample was also measured. 3 The volumetric porosity ε is calculated as follows: ε = [(m² - m¹) / (ρwater × V)] × 100%, where ρwater = 1 g / cm³. 3 Take the average of 5 parallel samples.

[0058] III. Wear resistance performance testing: Sample specifications: Φ100mm×3mm circular disc with a central hole, 5 parallel samples per group.

[0059] Pre-test treatment: The sample was kept at a constant temperature and humidity of 25℃ and 50% for 24 hours.

[0060] Test method: A Taber abrasion tester equipped with a CS-10 grinding wheel was used, with a load of 1000g set. The sample was pre-ground for 500 revolutions and then weighed (W1, mg), and then weighed again after 1000 revolutions (W2, mg). The wear mass ΔW = W1 - W2 (mg / 1000r) was calculated, and the average value of 5 parallel samples was taken.

[0061] IV. Elastic recovery rate test: Sample specifications: Φ29mm×12.5mm cylinder (samples are prepared separately by changing the mold), 5 parallel samples per group.

[0062] Pre-test treatment: The sample was kept at a constant temperature and humidity of 25℃ and 50% for 24 hours, and the initial average thickness h1 (mm) was measured.

[0063] Test method: A compression set tester was used, with a compression ratio of 25%; the sample was compressed and held at 70℃ for 22 hours; after unloading, the sample was placed in a standard environment (25℃, 50%RH) to recover for 24 hours, and the thickness h2 (mm) after recovery was measured. The elastic recovery rate η = (h2 / h1) × 100%, and the average value of 5 parallel samples was taken.

[0064] V. Chemical stability testing: Sample specifications: 10mm×10mm×3mm, 5 parallel samples per group.

[0065] Pre-test treatment: The sample was kept at a constant temperature and humidity of 25℃ and 50% for 24 hours, and then weighed m1 (g).

[0066] Test method: The sample was completely immersed in 5wt% H2SO4 aqueous solution, HNO3 aqueous solution with pH=2, 5wt% NaOH aqueous solution, KOH aqueous solution with pH=12, and deionized water (control) in a constant temperature water bath at 60℃ for 168h. After removal, it was washed 3 times with deionized water, vacuum dried at 85℃ for 4h, and weighed m2 (g) after cooling to standard environment. The mass change rate % = [(m2-m1) / m1]×100%, and the average value of 5 parallel samples was taken.

[0067] VI. Polishing precision, consistency, and scratch inspection: Sample specifications: Φ100mm×3mm, 10 samples per group.

[0068] Workpieces to be polished: Φ100mm silicon wafers (initial Ra≈0.2μm), 10 wafers per group.

[0069] Test method: A chemical mechanical polishing (CMP) tester was used, with the polishing pressure set at 20.7 kPa, the polishing disc / polishing head speed at 90 / 90 rpm, the standard SiO2 polishing fluid flow rate at 150 mL / min, and the polishing time at 30 min; each polishing pad sample corresponds to polishing one silicon wafer.

[0070] Polishing accuracy: The Ra value of 5 sites on the surface of each silicon wafer was measured by AFM and the average value was taken to calculate the average Ra value (μm) of 10 silicon wafers.

[0071] Consistency: Calculate the coefficient of variation (CV) of the average Ra value of 10 silicon wafers, CV = (standard deviation / average) × 100%.

[0072] Scratch detection: The entire surface of the silicon wafer was observed using a metallographic microscope at 500x magnification to count the number of scratches with a length >1μm.

[0073] Table 1. Test Results (Average Values) The performance advantages of Examples 1 to 3 stem from the synergistic design and process optimization of multiple scales and components: Using a double-ended epoxy-fluorinated block fluororubber prepolymer (EF-BFKM) as the core substrate, a rigid-flexible interpenetrating cross-linked network is formed with epoxy resin, and the microphase separation of fluorinated segments constructs a dense and smooth substrate; fillers with excellent compatibility, such as fluorinated modified mesoporous silica and fluorosilane-modified nanodiamonds, are used to prevent agglomeration and protrusions. Simultaneously, nanodiamonds strengthen the wear-resistant framework, and mesoporous microspheres optimize the pore structure; the dynamic covalent bonds of the fluorinated self-healing diluent release stress and repair micro-damage, while perfluoropolyether lubricants reduce the coefficient of friction; precise control of the surface micromorphology through plasma etching forms a low surface energy fluorine layer, reducing abrasive adhesion and media penetration. A stepped curing process reduces internal stress, ultimately achieving nanoscale ultra-precision polishing with low scratches, high elastic recovery rate, strong wear resistance, excellent chemical stability, and high consistency in batch polishing, comprehensively meeting the needs of ultra-precision machining.

[0074] In Comparative Example 1, EF-BFKM was insufficient, and epoxy resin was excessive. The system's crosslinking density was too high, transforming it from epoxy-reinforced fluororubber to fluororubber-modified epoxy resin. This resulted in a sharp decrease in molecular chain flexibility and a significant drop in elastic recovery rate. The insufficient proportion of fluorine segments led to an incomplete perfluorinated protective network and deteriorated chemical stability. Excessive epoxy resin increased brittleness after curing and reduced compatibility with fillers, resulting in increased surface roughness. Poor adhesion and increased hard contact during polishing led to decreased polishing precision, increased scratches, and deterioration in consistency.

[0075] Comparative Example 2 uses a non-fluorinated self-healing diluent. The lack of a dynamic covalent network means that microcracks generated during polishing cannot heal, leading to rapid deterioration of the surface morphology with use. Simultaneously, the absence of fluorinated groups from the diluent increases the system's surface energy and decreases its chemical stability. The diluent's filler dispersion effect disappears, resulting in uneven filler dispersion, increased surface roughness and wear. During polishing, uneven local wear occurs, pressure transmission fluctuates, consistency deteriorates, and scratches increase.

[0076] In Comparative Example 3, the self-healing diluent did not contain ADH. ADH is the core component for forming dynamic covalent bonds of acylhydrazone-aldehyde groups. Without its addition, the diluent is merely a static fluorinated toughening agent with no self-healing function; the static segments cannot release polishing pressure, resulting in a decrease in elastic recovery rate; the intermediate structure has poor stability and insufficient compatibility with the matrix, leading to reduced surface microstructure regularity and deterioration in polishing consistency and scratch index.

[0077] Furthermore, the core defect of Comparative Example 2 is the complete absence of a fluorinated self-healing diluent, resulting in the loss of only dynamic self-healing function and fluorinated group replenishment. Comparative Example 3, on the other hand, added an ineffective diluent that lacked a key reaction step, failing to incorporate ADH (adipic acid dihydrazide). This prevented the diluent from forming dynamic covalent bonds between acylhydrazone and aldehyde groups, rendering it merely a static fluorinated toughening agent. Moreover, this static intermediate exhibited poor structural stability and insufficient compatibility with the matrix. Comparative Example 3 not only lacked self-healing function but also, due to the presence of the ineffective diluent, introduced additional problems such as decreased filler dispersibility and weakened interfacial bonding with the matrix. This resulted in a cumulative deterioration of both self-healing and compatibility defects, making its overall performance worse than Comparative Example 2.

[0078] In Comparative Example 4, the filler was not fluorinated. The unfluorinated mesoporous silica and nanodiamond surface are rich in polar hydroxyl groups, which have extremely poor compatibility with the non-polar fluororubber matrix, leading to severe agglomeration of the filler. Agglomerated particles become stress concentration points, easily inducing cracks, while also blocking pore channels and causing pore structure failure. Agglomerated diamonds are easily detached during polishing, becoming additional abrasive and causing numerous scratches. The hydrophilic agglomerates provide permeation channels for acidic and alkaline media, resulting in a sharp deterioration in chemical stability and a comprehensive degradation of all properties.

[0079] In Comparative Example 5, the curing agent ratio was 3:1, with an excess of imidazole. The excessive imidazole content led to an imbalance in the crosslinking reaction, uneven crosslinking density distribution, and an increase in the proportion of rigid regions. Excess imidazole further reduced the flexibility of the cured product and significantly decreased the elastic recovery rate. Insufficient acid anhydride resulted in a reduction in fluorine group content and decreased chemical stability. Uneven crosslinking led to irregular surface microstructure, uneven pressure distribution during polishing, poor consistency, increased scratches, and the wear resistance was also affected by the uneven structure.

[0080] In Comparative Example 6, the high-temperature curing stage and vacuum post-treatment were omitted. Omitting the high-temperature holding stage prevents sufficient microphase separation of the fluorine chain segments, resulting in insufficient fluorine enrichment on the surface, high surface energy, and increased roughness. Incomplete cross-linking of molecular chains leads to residual small molecule impurities and internal stress, which cannot be removed without vacuum post-treatment, resulting in a porous structure and decreased wear resistance and elastic recovery rate. Residual small molecules provide penetration channels for acidic and alkaline media, reducing chemical stability. During polishing, the release of internal stress causes deformation of the polishing pad, uneven pressure transmission, deterioration of polishing precision and consistency, and an increase in scratches.

[0081] The amounts of dihydroxy perfluoropolyether (DHPO) and PFHEA in Comparative Example 7 were reduced. DHPO and PFHEA are core raw materials for the fluorinated blocks in EF-BFKM. A significant reduction in their usage directly resulted in an insufficient proportion of fluorinated blocks: on the one hand, the perfluorinated protective network was incomplete, weakening the low surface energy characteristics and chemical barrier effect of fluorine atoms, making it easier for acidic and alkaline media to penetrate and for abrasives to adhere; on the other hand, the block copolymerization reaction was insufficient, disrupting the rigid-flexible balance of EF-BFKM, reducing the flexibility of the molecular chains, and failing the synergistic effect of elastic recovery and wear resistance. Simultaneously, insufficient fluorinated blocks inhibited the microphase separation of fluorinated segments, leading to uneven surface morphology of the polishing pad, reduced pressure transmission and chip removal efficiency, ultimately resulting in deterioration of surface roughness, wear resistance, chemical stability, and polishing consistency.

Claims

1. An epoxy resin-based porous fluororubber polishing pad, characterized in that, It is prepared from the following raw materials in parts by weight: 55-65 parts EF-BFKM, 20-25 parts 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 5-8 parts fluorinated self-healing diluent, 4-6 parts fluorinated modified mesoporous silica microspheres, 5-7 parts curing agent, 1.2-1.8 parts PFHTES, 1.0-1.5 parts hexacarbon perfluoropolyether siloxane, 3-5 parts nano-diamond-fluorosilane composite powder, and 2-4 parts perfluoropolyether lubricant; The curing agent comprises 2-ethyl-4-methylimidazolium and 4,4-hexafluoroisopropylphthalic anhydride in a mass ratio of 1:(2.5-3.5). The EF-BFKM is a prepolymer of double-ended epoxy-fluorinated block fluororubber. It is prepared by reacting carboxyl-terminated fluororubber, TBAB, and ECH in NMP, adding dihydroxy perfluoropolyether, PFHEA, and DBTDL, adding DEA, adding antioxidant 1076, stirring to obtain a reaction solution, and then precipitating, washing, drying, and pulverizing it. The mass ratio of carboxyl-terminated fluororubber:TBAB:ECH:dihydroxy perfluoropolyether:PFHEA:DBTDL:DEA:antioxidant 1076 is (100~120):(4.0~4.5):(25~30):(30~40):(20~25):(0.5~0.8):(5~8):(0.8~1.0). The fluorinated self-healing diluent is prepared by reacting 2-perfluorooctylethanol and PTSA in ethanol, adding HQ and TPAL, adding ADH, distilling under reduced pressure, washing, and drying; the mass ratio of 2-perfluorooctylethanol:PTSA:HQ:TPAL:ADH is (35-45):(1.0-1.5):(0.3-0.5):(16-20):(22-28). The fluorinated modified mesoporous silica microspheres are prepared by modifying mesoporous silica microspheres with PFHTES. The nanodiamond-fluorosilane composite powder is prepared by hydroxylating nanodiamond powder in ethanol with concentrated nitric acid, followed by modification with PFHTES and BYK-110 in ethanol.

2. The epoxy resin-based porous fluororubber polishing pad according to claim 1, characterized in that, The preparation method of EF-BFKM includes the following steps: Under nitrogen protection, 100-120 parts by mass of carboxyl-terminated fluororubber are added to 300-350 parts by mass of NMP and stirred to obtain fluororubber mother liquor. 4.0-4.5 parts of TBAB and 25-30 parts of ECH are added, and the mixture is refluxed and stirred to react. 30-40 parts of dihydroxy perfluoropolyether, 20-25 parts of PFHEA, and 0.5-0.8 parts of DBTDL are added, and the mixture is stirred to react for 6-8 hours. 5-8 parts of DEA are added, and the mixture is stirred to react. 0.8-1.0 parts of antioxidant 1076 are added, and the mixture is stirred to obtain a reaction solution. The reaction solution is added to deionized water, stirred, allowed to stand and separate into layers, the precipitate is collected, washed, vacuum dried, and pulverized to obtain EF-BFKM with a particle size between 80 and 120 mesh.

3. The epoxy resin-based porous fluororubber polishing pad according to claim 2, characterized in that, The carboxyl-terminated fluororubber and NMP were stirred at 85℃~90℃ for 1h~1.5h; after the addition of TBAB and ECH, the mixture was refluxed and stirred at 95℃~100℃ for 5h~6h; after the addition of dihydroxy perfluoropolyether, PFHEA, and DBTDL, the mixture was refluxed and stirred for 6h~8h; DEA was added at 80℃~85℃; after the addition of DEA, the mixture was stirred for 3h~4h; the amount of deionized water used was 4 to 4.5 times the volume of the reaction liquid, and the temperature of the deionized water was 50℃~55℃; the precipitate was washed with anhydrous methanol.

4. The epoxy resin-based porous fluororubber polishing pad according to claim 1, characterized in that, The preparation method of the fluorinated self-healing diluent includes the following steps: by mass parts, 140-160 parts of ethanol, 35-45 parts of 2-perfluorooctylethanol, and 1.0-1.5 parts of PTSA are mixed, refluxed and stirred, 0.3-0.5 parts of HQ and 16-20 parts of TPAL are added, and the mixture is stirred to react. Then, 22-28 parts of ADH are added, and the mixture is stirred to react. The mixture is then distilled under reduced pressure, washed with deionized water, and dried under vacuum to obtain the fluorinated self-healing diluent.

5. The epoxy resin-based porous fluororubber polishing pad according to claim 4, characterized in that, The reflux stirring is carried out at 65℃~70℃ for 1h~1.5h; after the addition of HQ and TPAL, the reaction is stirred for 2.5h~3.5h; the ADH is added at 45℃~55℃, and the reaction is stirred for 3.5h~4.5h; the ethanol is removed by vacuum distillation.

6. The epoxy resin-based porous fluororubber polishing pad according to claim 1, characterized in that, The preparation method of the fluorinated modified mesoporous silica microspheres includes the following steps: under nitrogen protection, the mesoporous silica microspheres are dispersed in anhydrous ethanol and ultrasonically treated to form a suspension; PFHTES is added, the pH is adjusted to 4-5, the mixture is refluxed and stirred, filtered, the filter cake is washed with anhydrous ethanol, and vacuum dried to obtain fluorinated modified mesoporous silica microspheres.

7. The epoxy resin-based porous fluororubber polishing pad according to claim 6, characterized in that, The amount of anhydrous ethanol used is 8 to 10 times the mass of the mesoporous silica microspheres; the amount of PFHTES added is 10% to 15% of the mass of the mesoporous silica microspheres; the condensation and reflux stirring is carried out at 65°C to 70°C for 4 to 6 hours.

8. The epoxy resin-based porous fluororubber polishing pad according to claim 1, characterized in that, The preparation method of the nanodiamond-fluorosilane composite powder includes the following steps: dispersing nanodiamond powder in anhydrous ethanol, adding concentrated nitric acid, refluxing and stirring, filtering, washing the filter cake with deionized water until neutral, vacuum drying to obtain hydroxylated nanodiamond powder, dispersing it in anhydrous ethanol, adding PFHTES, adding BYK-110, refluxing and stirring, filtering, washing the filter cake with anhydrous ethanol, vacuum drying, and pulverizing to a median particle size of 80nm to 150nm to obtain nanodiamond-fluorosilane composite powder.

9. The epoxy resin-based porous fluororubber polishing pad according to claim 8, characterized in that, The concentration of the concentrated nitric acid is 65wt% to 68wt%; the amount of concentrated nitric acid added is 20% to 30% of the mass of the nanodiamond powder; after the concentrated nitric acid is added, the mixture is refluxed and stirred at 65℃ to 70℃ for 3 to 4 hours; the amount of PFHTES added is 8% to 12% of the mass of the hydroxylated nanodiamond powder; the amount of BYK-110 added is 2% to 4% of the mass of the hydroxylated nanodiamond powder; after the BYK-110 is added, the mixture is refluxed and stirred at 60℃ to 70℃ for 3 to 4 hours.

10. The method for preparing an epoxy resin-based porous fluororubber polishing pad according to claim 1, characterized in that, Includes the following steps: S1: According to the formula, EF-BFKM, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, and fluorinated self-healing diluent are mixed at 100℃~110℃ for 30min~40min, cooled to 60℃~70℃, fluorinated modified mesoporous silica microspheres, PFHTES, hexacarbon perfluoropolyether siloxane, and nanodiamond-fluorosilane composite powder are added, mixed evenly, and vacuum degassed. Perfluoropolyether lubricant and curing agent are added, mixed evenly, and vacuum degassed to obtain slurry; S2: Pour the slurry into the mold and cure it at 4MPa~6MPa and 70℃~80℃ for 2h~3h, at 6MPa~8MPa and 120℃~130℃ for 2.5h~3.5h, and at 1MPa~3MPa and 140℃~160℃ for 2h~3h; after cooling to room temperature, demold to obtain the rough polishing pad. S3: Vacuum treatment at 150℃~160℃ for 30min~40min, followed by thickness and leveling grinding, and plasma treatment to obtain a polishing pad.

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