Novel polishing pad

Abstract

The invention discloses a novel polishing pad, and relates to the technical field of polishing pads, the novel polishing pad comprises, by weight, 50-70 parts of a diamond abrasive, 20-40 parts of a composite binder, 0.5-5 parts of an auxiliary additive, and 1-20 parts of nano diamond; the composite binding agent comprises the following components in percentage by mass: 65-75% of a ceramic binding agent and 25-35% of a resin binding agent; the ceramic bond contains lanthanum oxide; the diamond abrasive material is B-N co-doped diamond doped with boron and nitrogen. According to the novel polishing pad, the B-N co-doped diamond abrasive and the lanthanum oxide-containing composite binding agent cooperate with the nano-diamond, so that the heat resistance, the wear resistance and the polishing efficiency of the novel polishing pad are remarkably improved, the quality of the polished surface is effectively improved, and the effect of reducing the use cost is achieved.

Description

Technical Field

[0001] This application relates to the field of polishing pad technology, and in particular to a novel polishing pad. Background Technology

[0002] Diamond polishing pads are disc-shaped or sheet-shaped polishing tools in which diamond micro-powder or diamond particles are embedded or coated on a substrate, such as cloth, fiber cloth, or backing pad, with a suitable binder, such as resin or ceramic-resin mixture.

[0003] In existing technologies, diamond polishing pads are mainly used in industries such as stone processing, floor renovation, artificial stone and concrete surface treatment. They can polish the surface or edges of materials such as granite, marble, quartz stone and concrete, remove scratches and defects, achieve a high-gloss finish, and restore the vitality of old and worn surfaces.

[0004] Currently, the binders for diamond polishing pads are mainly divided into two types: resin binders and ceramic binders. The core components of resin binders are organic polymers such as epoxy resin and phenolic resin. They rely on the adhesive properties of the resin to encapsulate diamond particles, belonging to an organic bonding system. The core components of ceramic binders are inorganic minerals such as glass powder, feldspar, and clay. They rely on high-temperature sintering to form an inorganic crystalline structure, anchoring the diamond particles, belonging to an inorganic sintering system.

[0005] However, because the resin used in the resin binder is an organic polymer material, it is prone to softening and carbonization at temperatures exceeding 150℃, resulting in a decrease in the holding force of the diamond particles and making it difficult to use under high-load, high-speed polishing conditions. Furthermore, although the ceramic binder is rigid, it lacks elasticity and is prone to cracking and chipping when subjected to impact or rapid heating and cooling, thus affecting its service life and requiring improvement. Summary of the Invention

[0006] In view of this, the purpose of this application is to provide a novel polishing pad to improve heat resistance, wear resistance, and reduce usage costs. The specific solution is as follows: A novel polishing pad comprises 50-70 parts by weight of diamond abrasive, 20-40 parts by weight of composite binder, 0.5-5 parts by weight of auxiliary additives, and 1-20 parts by weight of nanodiamond; the composite binder comprises 65-75% by weight of ceramic binder and 25-35% by weight of resin binder; the ceramic binder contains lanthanum oxide; and the diamond abrasive is boron and nitrogen-doped BN co-doped diamond.

[0007] Preferably, the ceramic binder is composed of silicon dioxide, aluminum oxide, calcium oxide, barium sulfate and lanthanum oxide in a mass ratio of 30:33-35:14.5-16:14.5-16:4.5-5.

[0008] Preferably, the preparation method of the ceramic binder includes step ① mixing silicon dioxide, alumina, calcium oxide, and barium sulfate, ball milling, and drying to obtain ceramic base powder, and calcining lanthanum oxide to obtain lanthanum oxide; step ② adding the ceramic base powder and lanthanum oxide into deionized water and stirring to obtain a mixed suspension with a solid content of 35-45%, then adding a dispersant accounting for 0.5-0.6% of the solid mass to the mixed suspension, and after ultrasonic dispersion and stirring, spray drying to obtain lanthanum oxide-doped ceramic composite powder; step ③ sintering the ceramic composite powder to remove the dispersant and lanthanum oxide diffusion to obtain modified ceramic binder powder.

[0009] Preferably: in step ①, the calcination treatment is carried out at a controlled temperature of 580-600℃ for 2-2.5h; in step ②, the dispersant is polyvinylpyrrolidone, and the spray drying treatment is carried out at a controlled inlet air temperature of 180-185℃ and an outlet air temperature of 78-82℃; in step ③, the sintering is carried out by first controlling the heating rate at 5℃ / min to raise the temperature to 580-600℃ and holding it at that temperature for 1-1.2h, then controlling the heating rate at 10℃ / min to raise the temperature to 1200-1220℃ and holding it at that temperature for 2-2.1h, and finally controlling the cooling rate at 2-5℃ / min to cool down to room temperature.

[0010] Preferably, the preparation method of the resin binder includes step ① mixing and stirring 90-100 parts by weight of E51 epoxy resin with 45-50 parts by weight of toluene to obtain an epoxy resin solution; step ② adding 0.9-1% by weight of catalyst to the epoxy resin solution, followed by adding 9.5-10% by weight of KH550 silane coupling agent, and heating to 88-90℃ and holding for 6-6.2 hours after the addition is completed to obtain a silane-grafted epoxy resin mixture; step ③ distilling the silane-grafted epoxy resin mixture under reduced pressure to obtain a silane-grafted epoxy resin.

[0011] Preferably, in step ②, the catalyst is dibutyltin dilaurate, the KH550 silane coupling agent is added using a KH550 silane coupling agent solution, and the pH of the KH550 silane coupling agent solution is 4-5, obtained by mixing with deionized water at a volume ratio of 1:10 and hydrolyzing for 30-35 minutes; in step ③, the vacuum distillation is carried out by controlling the vacuum degree to -0.09 MPa and the temperature to 98-100℃.

[0012] Preferably, the preparation method of BN co-doped diamond includes step ① degassing diamond abrasive at a temperature of 980-1000℃ to obtain pretreated diamond abrasive; step ② mixing the pretreated diamond abrasive with boric acid and melamine at a ratio of 5:1-1.1:1-1.1, and obtaining doped diamond after doping treatment; step ③ cleaning the doped diamond with dilute hydrochloric acid and obtaining BN co-doped diamond after vacuum drying treatment.

[0013] Preferably, the doping treatment includes controlling the pressure to be 4.8-5 GPa, the temperature to be 1400-1420℃, and the time to be 2-2.1 h.

[0014] Preferably, the auxiliary additives are 0.15-2 parts of dispersant, 0.25-2.5 parts of binder and 0.1-0.5 parts of defoamer; the dispersant is sodium hexadecyl sulfate or polyvinylpyrrolidone, the binder is water glass or dextrin, and the defoamer is polydimethylsiloxane.

[0015] Preferably, the nanodiamond is a hierarchical micro / nanostructured diamond. The preparation method of the hierarchical micro / nanostructured diamond includes step ① cutting an anodized aluminum template into a specified shape, cleaning it with 5% hydrochloric acid and drying it to obtain a loading template; step ② mixing the nanodiamond raw material with deionized water at a ratio of 1g:185-200mL, then adding polyethyleneimine at a volume ratio of 1:4500-5000 with deionized water, ultrasonically dispersing it evenly, and then adding the loading template at a mass ratio of 50-60:1 to the nanodiamond raw material and allowing it to stand for 1-1.2h to obtain the loading template; step ③ immersing the loading template in a 10% sodium hydroxide solution, keeping it at a temperature of 48-50℃ for 14-16min, and then drying it to obtain the hierarchical micro / nanostructured diamond.

[0016] As can be seen from the above solutions, this application provides a novel polishing pad, which has the following beneficial effects: 1. By adding lanthanum oxide to the ceramic binder to refine the grains and fill grain boundary defects, and by using KH550 to graft silicon-oxygen functional groups into the resin binder, chemical bonds are formed with the surface groups of BN co-doped diamond; and BN co-doping enhances the lattice stability of diamond, thereby achieving mutual synergy and significantly improving the structural stability and heat resistance of the new polishing pad at high temperature. 2. By adopting lattice substitution, the hardness and oxidation resistance of BN co-doped diamond are significantly improved. In addition, the improved composite binder makes it have sufficient rigidity and toughness, thereby improving the wear resistance of diamond abrasive. Furthermore, the multi-level micro-nano structured nanodiamond increases the contact area and reduces the shedding of diamond abrasive, thereby extending its service life. 3. The ceramic phase in the composite binder provides strong cutting force, the resin phase buffers and reduces scratches, and the micro-nano structured nanodiamond forms a gradient cutting edge, thereby effectively assisting in the removal of defects. Detailed Implementation

[0017] The technical solutions described below in conjunction with the embodiments of this application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] It should be mentioned that the auxiliary additives in the embodiments of this application include dispersants, binders, and defoamers. The dispersant is sodium hexadecyl sulfate or polyvinylpyrrolidone, the binder is water glass or dextrin, and the defoamer is polydimethylsiloxane. Specifically, in the embodiments of this application, sodium hexadecyl sulfate is used as the dispersant, and water glass is used as the binder.

[0019] The following is a detailed description of a novel polishing pad according to this application.

[0020] A novel polishing pad comprises 50-70 parts by weight of diamond abrasive, 20-40 parts by weight of composite binder, 0.5-5 parts by weight of auxiliary additives, and 1-20 parts by weight of nanodiamond. The composite binder comprises 65-75% by weight of ceramic binder and 25-35% by weight of resin binder. The diamond abrasive is boron- and nitrogen-doped BN co-doped diamond. The ceramic binder consists of silicon dioxide, aluminum oxide, calcium oxide, barium sulfate, and lanthanum oxide in a mass ratio of 30:33-35:14.5-16:14.5-16:4.5-5. The auxiliary additives consist of 0.15-2 parts by weight of dispersant, 0.25-2.5 parts by weight of binder, and 0.1-0.5 parts by weight of defoamer.

[0021] It should be noted that the preparation method of the ceramic binder includes the following steps: Step ① Mixing silicon dioxide, alumina, calcium oxide, and barium sulfate, ball milling, and drying to obtain ceramic base powder, and calcining lanthanum oxide to obtain lanthanum oxide; Step ② Adding the ceramic base powder and lanthanum oxide to deionized water and stirring to obtain a mixed suspension with a solid content of 35-45%, then adding a dispersant accounting for 0.5-0.6% of the solid mass to the mixed suspension, and after ultrasonic dispersion and stirring, spray drying to obtain lanthanum oxide-doped ceramic composite powder; Step ③ Sintering the ceramic composite powder to remove the dispersant and lanthanum oxide diffusion to obtain modified ceramic binder powder.

[0022] In step ① of the method for preparing the ceramic binder, the calcination treatment involves controlling the temperature at 580-600℃ and calcining for 2-2.5 hours. In step ②, the dispersant is polyvinylpyrrolidone, and the spray drying treatment involves controlling the inlet air temperature at 180-185℃ and the outlet air temperature at 78-82℃. In step ③, the sintering process involves first controlling the heating rate at 5℃ / min to raise the temperature to 580-600℃ and holding it at that temperature for 1-1.2 hours, then controlling the heating rate at 10℃ / min to raise the temperature to 1200-1220℃ and holding it at that temperature for 2-2.1 hours, and finally controlling the cooling rate at 2-5℃ / min to cool to room temperature.

[0023] Meanwhile, the preparation method of the resin binder includes step ① mixing and stirring 90-100 parts by weight of E51 epoxy resin with 45-50 parts by weight of toluene to obtain an epoxy resin solution; step ② adding 0.9-1% by weight of catalyst to the epoxy resin solution, followed by adding 9.5-10% by weight of KH550 silane coupling agent, and heating to 88-90℃ and holding for 6-6.2 hours after the addition is completed to obtain a silane-grafted epoxy resin mixture; step ③ distilling the silane-grafted epoxy resin mixture under reduced pressure to obtain silane-grafted epoxy resin.

[0024] In step ② of the resin binder preparation method, the catalyst is dibutyltin dilaurate, and the KH550 silane coupling agent is added using a KH550 silane coupling agent solution with a pH of 4-5. The solution is obtained by mixing with deionized water at a volume ratio of 1:10 and hydrolyzing for 30-35 minutes. In step ③, the vacuum distillation is performed with a controlled vacuum of -0.09 MPa and a temperature of 98-100℃.

[0025] It should be mentioned that the preparation method of BN co-doped diamond includes the following steps: Step ① Degassing diamond abrasive at a temperature of 980-1000℃ to obtain pretreated diamond abrasive; Step ② Mixing the pretreated diamond abrasive with boric acid and melamine at a ratio of 5:1-1.1:1-1.1, and obtaining doped diamond after doping treatment; Step ③ Cleaning the doped diamond with dilute hydrochloric acid and obtaining BN co-doped diamond after vacuum drying treatment.

[0026] In the preparation method of BN co-doped diamond, the doping treatment includes controlling the pressure to be 4.8-5 GPa, the temperature to be 1400-1420℃, and the time to be 2-2.1 h.

[0027] Nanodiamonds are hierarchical micro / nano-structured diamonds, and the preparation method of hierarchical micro / nano-structured diamonds includes the following steps: Step ① Cutting an anodic aluminum oxide template into a specified shape, cleaning and drying it with 5% hydrochloric acid to obtain a loading template; Step ② Mixing nanodiamond raw materials with deionized water at a ratio of 1g:185-200mL, then adding polyethyleneimine at a volume ratio of 1:4500-5000 with deionized water, ultrasonically dispersing it evenly, and then adding the loading template at a mass ratio of 50-60:1 to the nanodiamond raw materials and allowing it to stand for 1-1.2h to obtain the loading template; Step ③ Immersing the loading template in a 10% sodium hydroxide solution, keeping it at a temperature of 48-50℃ for 14-16min, and then drying it to obtain hierarchical micro / nano-structured diamonds.

[0028] Example 1 A novel polishing pad comprises 50 parts by weight of diamond abrasive, 20 parts by weight of composite binder, 0.5 parts by weight of auxiliary additives, and 1 part by weight of nanodiamond. The composite binder comprises 65% by weight of ceramic binder and 35% by weight of resin binder. The diamond abrasive is boron- and nitrogen-doped (BN) co-doped diamond. The ceramic binder consists of silicon dioxide, aluminum oxide, calcium oxide, barium sulfate, and lanthanum oxide in a mass ratio of 30:33:14.5:14.5:4.5. The auxiliary additives are 0.15 parts by weight of dispersant, 0.25 parts by weight of binder, and 0.1 parts by weight of defoamer.

[0029] It should be noted that the preparation method of the ceramic binder includes the following steps: Step ① Mixing silicon dioxide, alumina, calcium oxide, and barium sulfate, ball milling, and drying to obtain ceramic base powder, and calcining lanthanum oxide to obtain lanthanum oxide; Step ② Adding the ceramic base powder and lanthanum oxide to deionized water and stirring to obtain a mixed suspension with a solid content of 35%, then adding 0.5% polyvinylpyrrolidone by solid mass to the mixed suspension, and after ultrasonic dispersion and stirring, spray drying to obtain lanthanum oxide-doped ceramic composite powder; Step ③ Sintering the ceramic composite powder to remove the dispersant and lanthanum oxide diffusion to obtain modified ceramic binder powder.

[0030] In step ① of the method for preparing the ceramic binder, the calcination treatment is carried out at a controlled temperature of 580℃ for 2.5 hours. In step ②, the spray drying treatment is carried out at a controlled inlet air temperature of 180℃ and an outlet air temperature of 78℃. In step ③, the sintering treatment is carried out by first controlling the heating rate at 5℃ / min to raise the temperature to 580℃ and holding it at that temperature for 1.2 hours, then controlling the heating rate at 10℃ / min to raise the temperature to 1200℃ and holding it at that temperature for 2.1 hours, and finally controlling the cooling rate at 2℃ / min to cool down to room temperature.

[0031] Meanwhile, the preparation method of the resin binder includes step ① mixing 90 parts by weight of E51 epoxy resin with 45 parts by weight of toluene and stirring evenly to obtain an epoxy resin solution; step ② adding 0.9% by weight of dibutyltin dilaurate to the epoxy resin solution, followed by adding 9.5% by weight of KH550 silane coupling agent, and then heating to 88℃ and holding for 6.2h after the addition is completed to obtain a silane-grafted epoxy resin mixture; step ③ distilling the silane-grafted epoxy resin mixture under reduced pressure to obtain silane-grafted epoxy resin.

[0032] In step ② of the resin binder preparation method, KH550 silane coupling agent is added using a KH550 silane coupling agent solution with a pH of 4. This solution is obtained by mixing with deionized water at a volume ratio of 1:10 and hydrolyzing for 30 minutes. In step ③, vacuum distillation is performed at a controlled vacuum of -0.09 MPa and a temperature of 98°C.

[0033] It should be mentioned that the preparation method of BN co-doped diamond includes step ① degassing the diamond abrasive at a temperature of 980℃ to obtain pretreated diamond abrasive; step ② mixing the pretreated diamond abrasive with boric acid and melamine in a ratio of 5:1:1, and obtaining doped diamond after doping treatment; step ③ cleaning the doped diamond with dilute hydrochloric acid and obtaining BN co-doped diamond after vacuum drying treatment.

[0034] In the preparation method of BN co-doped diamond, the doping treatment includes controlling the pressure at 4.8 GPa, the temperature at 1400℃, and the time at 2.1 h.

[0035] Nanodiamonds are hierarchical micro / nano-structured diamonds. The preparation method of hierarchical micro / nano-structured diamonds includes the following steps: ① Cutting an anodic aluminum oxide template into a specified shape, cleaning it with 5% hydrochloric acid and drying it to obtain a loading template; ② Mixing nanodiamond raw materials with deionized water at a ratio of 1g:185mL, then adding polyethyleneimine at a volume ratio of 1:4500 to deionized water, ultrasonically dispersing it evenly, and then adding a loading template at a mass ratio of 50:1 to the nanodiamond raw materials and letting it stand for 1 hour to obtain a loading template; ③ Immersing the loading template in a 10% sodium hydroxide solution, keeping it at 48℃ for 16 minutes, and then drying it to obtain hierarchical micro / nano-structured diamonds.

[0036] Example 2 A novel polishing pad comprises 60 parts by weight of diamond abrasive, 30 parts by weight of composite binder, 2 parts by weight of auxiliary additives, and 10 parts by weight of nanodiamond. The composite binder comprises 70% by weight of ceramic binder and 30% by weight of resin binder. The diamond abrasive is boron- and nitrogen-doped BN co-doped diamond. The ceramic binder consists of silicon dioxide, aluminum oxide, calcium oxide, barium sulfate, and lanthanum oxide in a mass ratio of 30:34:15:15:4.8. The auxiliary additives are 0.6 parts by weight of dispersant, 1.2 parts by weight of binder, and 0.2 parts by weight of defoamer.

[0037] It should be noted that the preparation method of the ceramic binder includes the following steps: Step ① Mixing silicon dioxide, alumina, calcium oxide, and barium sulfate, ball milling, and drying to obtain ceramic base powder, and calcining lanthanum oxide to obtain lanthanum oxide; Step ② Adding the ceramic base powder and lanthanum oxide to deionized water and stirring to obtain a mixed suspension with a solid content of 40%, then adding 0.55% polyvinylpyrrolidone by solid mass to the mixed suspension, and after ultrasonic dispersion and stirring, spray drying to obtain lanthanum oxide-doped ceramic composite powder; Step ③ Sintering the ceramic composite powder to remove the dispersant and lanthanum oxide diffusion to obtain modified ceramic binder powder.

[0038] In step ① of the method for preparing the ceramic binder, the calcination treatment is carried out at a controlled temperature of 590℃ for 2.2 hours. In step ②, the spray drying treatment is carried out at a controlled inlet air temperature of 183℃ and an outlet air temperature of 80℃. In step ③, the sintering treatment is carried out by first controlling the heating rate at 5℃ / min to raise the temperature to 590℃ and holding it at that temperature for 1.1 hours, then controlling the heating rate at 10℃ / min to raise the temperature to 1210℃ and holding it at that temperature for 2.1 hours, and finally controlling the cooling rate at 4℃ / min to cool down to room temperature.

[0039] Meanwhile, the preparation method of the resin binder includes step ① mixing and stirring 96 parts by weight of E51 epoxy resin and 48 parts by weight of toluene to obtain an epoxy resin solution; step ② adding 0.95% by weight of dibutyltin dilaurate to the epoxy resin solution, followed by adding 9.8% by weight of KH550 silane coupling agent, and then heating to 89℃ and holding for 6.1h after the addition is completed to obtain a silane-grafted epoxy resin mixture; step ③ distilling the silane-grafted epoxy resin mixture under reduced pressure to obtain silane-grafted epoxy resin.

[0040] In step ② of the resin binder preparation method, KH550 silane coupling agent is added using a KH550 silane coupling agent solution with a pH of 4.5. This solution is obtained by mixing with deionized water at a volume ratio of 1:10 and hydrolyzing for 32 minutes. In step ③, vacuum distillation is performed at a controlled vacuum of -0.09 MPa and a temperature of 99°C.

[0041] It should be mentioned that the preparation method of BN co-doped diamond includes step ① degassing the diamond abrasive at a temperature of 990℃ to obtain pretreated diamond abrasive; step ② mixing the pretreated diamond abrasive with boric acid and melamine in a ratio of 5:1:1.1, and obtaining doped diamond after doping treatment; step ③ cleaning the doped diamond with dilute hydrochloric acid and obtaining BN co-doped diamond after vacuum drying treatment.

[0042] In the preparation method of BN co-doped diamond, the doping treatment includes controlling the pressure at 4.9 GPa, the temperature at 1410 °C, and the time at 2.1 h.

[0043] Nanodiamonds are hierarchical micro / nano-structured diamonds, and the preparation method of hierarchical micro / nano-structured diamonds includes the following steps: Step ① Cutting an anodic aluminum oxide template into a specified shape, cleaning and drying it with 5% hydrochloric acid to obtain a loading template; Step ② Mixing nanodiamond raw materials with deionized water at a ratio of 1g:190mL, then adding polyethyleneimine at a volume ratio of 1:4800 to deionized water, ultrasonically dispersing it evenly, and then adding the loading template at a mass ratio of 55:1 to the nanodiamond raw materials and letting it stand for 1.1h to obtain the loading template; Step ③ Immersing the loading template in a 10% sodium hydroxide solution, keeping it at 49℃ for 15min, and then drying it to obtain hierarchical micro / nano-structured diamonds.

[0044] Example 3 A novel polishing pad comprises 70 parts by weight of diamond abrasive, 40 parts by weight of composite binder, 5 parts by weight of auxiliary additives, and 20 parts by weight of nanodiamond. The composite binder comprises 75% by weight of ceramic binder and 25% by weight of resin binder. The diamond abrasive is boron- and nitrogen-doped (BN) co-doped diamond. The ceramic binder consists of silicon dioxide, aluminum oxide, calcium oxide, barium sulfate, and lanthanum oxide in a mass ratio of 30:35:16:16:5. The auxiliary additives consist of 2 parts by weight of dispersant, 2.5 parts by weight of binder, and 0.5 parts by weight of defoamer.

[0045] It should be noted that the preparation method of the ceramic binder includes the following steps: Step ① Mixing silicon dioxide, alumina, calcium oxide, and barium sulfate, ball milling, and drying to obtain ceramic base powder, and calcining lanthanum oxide to obtain lanthanum oxide; Step ② Adding the ceramic base powder and lanthanum oxide to deionized water and stirring to obtain a mixed suspension with a solid content of 45%, then adding 0.6% polyvinylpyrrolidone by solid mass to the mixed suspension, and after ultrasonic dispersion and stirring, spray drying to obtain lanthanum oxide-doped ceramic composite powder; Step ③ Sintering the ceramic composite powder to remove the dispersant and lanthanum oxide diffusion to obtain modified ceramic binder powder.

[0046] In step ① of the method for preparing the ceramic binder, the calcination treatment is carried out at a controlled temperature of 600℃ for 2 hours. In step ②, the spray drying treatment is carried out at a controlled inlet air temperature of 185℃ and an outlet air temperature of 82℃. In step ③, the sintering treatment is carried out by first controlling the heating rate at 5℃ / min to raise the temperature to 600℃ and holding it at that temperature for 1 hour, then controlling the heating rate at 10℃ / min to raise the temperature to 1220℃ and holding it at that temperature for 2 hours, and finally controlling the cooling rate at 5℃ / min to cool down to room temperature.

[0047] Meanwhile, the preparation method of the resin binder includes step ① mixing 100 parts by weight of E51 epoxy resin with 50 parts by weight of toluene and stirring evenly to obtain an epoxy resin solution; step ② adding 1% by weight of dibutyltin dilaurate of E51 epoxy resin to the epoxy resin solution, and then adding 10% by weight of KH550 silane coupling agent of E51 epoxy resin, and heating to 90℃ and holding for 6 hours after the addition is completed to obtain a silane-grafted epoxy resin mixture; step ③ distilling the silane-grafted epoxy resin mixture under reduced pressure to obtain silane-grafted epoxy resin.

[0048] In step ② of the resin binder preparation method, KH550 silane coupling agent is added using a KH550 silane coupling agent solution with a pH of 5. This solution is obtained by mixing with deionized water at a volume ratio of 1:10 and hydrolyzing for 35 minutes. In step ③, vacuum distillation is performed at a controlled vacuum of -0.09 MPa and a temperature of 100°C.

[0049] It should be mentioned that the preparation method of BN co-doped diamond includes step ① degassing diamond abrasive at 1000℃ to obtain pretreated diamond abrasive; step ② mixing the pretreated diamond abrasive with boric acid and melamine in a ratio of 5:1.1:1, and obtaining doped diamond after doping treatment; step ③ cleaning the doped diamond with dilute hydrochloric acid and obtaining BN co-doped diamond after vacuum drying treatment.

[0050] In the preparation method of BN co-doped diamond, the doping treatment includes controlling the pressure at 5 GPa, the temperature at 1420 °C, and the time at 2 h.

[0051] Nanodiamonds are hierarchical micro / nano-structured diamonds, and the preparation method of hierarchical micro / nano-structured diamonds includes the following steps: Step ① Cutting an anodic aluminum oxide template into a specified shape, cleaning and drying it with 5% hydrochloric acid to obtain a loading template; Step ② Mixing nanodiamond raw materials with deionized water at a ratio of 1g:200mL, then adding polyethyleneimine at a volume ratio of 1:5000 to deionized water, ultrasonically dispersing it evenly, and then adding the loading template at a mass ratio of 60:1 to the nanodiamond raw materials and letting it stand for 1.2h to obtain the loading template; Step ③ Immersing the loading template in a 10% sodium hydroxide solution, keeping it at 50℃ for 14min, and then drying it to obtain hierarchical micro / nano-structured diamonds.

[0052] Comparative Example 1 The difference between Comparative Example 1 and Example 3 is that lanthanum oxide was not added to the ceramic binder in Comparative Example 1.

[0053] Comparative Example 2 The difference between Comparative Example 2 and Example 3 is that the diamond abrasive in Comparative Example 2 was not doped with boron and nitrogen.

[0054] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the resin binder in Comparative Example 3 is E51 epoxy resin that has not been grafted with KH550 silane coupling agent.

[0055] Comparative Example 4 The difference between Comparative Example 4 and Example 3 is that Comparative Example 4 uses nanodiamond instead of multi-level micro-nano structure diamond.

[0056] Performance testing: 1. Polishing efficiency: According to GB / T 30038-2013 "Test method for grinding performance of ordinary abrasives", 45# steel was selected as the polishing substrate. The pressure of 0.3MPa, the rotation speed of 300r / min and the polishing time of 30min were used to calculate the amount of substrate removed per unit time (mg / min). 2. Abrasive bonding strength: Conventional bonding strength testing methods were used. The critical tensile force at which the abrasive detaches from the polishing pad substrate was tested using a tensile testing machine. After 100 polishing cycles, the percentage of abrasive detachment was observed. 3. Polishing pad wear resistance: According to GB / T 9258.2-2008 "Coated Abrasives Part 2: Dimensions and Tolerances", the wear amount (mm) of the polishing pad thickness was tested after 10 hours of continuous polishing. 4. Temperature stability of binder: According to GB / T 16995-1997 "Test method for heat resistance of thermosetting resin matrix composites", the temperature range is controlled at 25-300℃, the heating rate is 5℃ / min, and the heat distortion temperature (HDT) of binder is tested.

[0057] Performance tests were conducted on Examples 1 to 3 and Comparative Examples 1 to 4, and the results are shown in Table 1 below.

[0058] Table 1 Performance Test Results

[0059] As shown in Table 1 above, in Examples 1 to 3 of this application, the increased content of diamond abrasive and nanodiamond improves density while simultaneously enhancing hardness and cutting force through the increased proportion of ceramic binder in the composite binder. Furthermore, the synergistic effect of BN co-doped diamond further enhances polishing efficiency. In Comparative Example 1, the lack of lanthanum oxide leads to a grain refinement effect, resulting in increased porosity and decreased hardness and density of the composite binder. This reduces the interfacial bonding between the abrasive and the composite binder, causing the abrasive to easily detach and leading to decreased polishing efficiency and thermal stability. In Comparative Example 2, the absence of BN co-doping in the diamond results in decreased hardness and difficulty in effectively improving the interfacial bonding between the diamond and the composite binder, significantly reducing polishing efficiency. In Comparative Example 3, the lack of active functional groups on the surface of the E51 epoxy resin results in an interfacial force between it and the ceramic binder and the diamond-based abrasive, which is only van der Waals force, far lower than the covalent bond force formed after grafting. This leads to decreased polishing efficiency and wear resistance. In Comparative Example 4, the decrease in cutting uniformity leads to a decrease in polishing efficiency. The decrease is not significant in the test data, but it is difficult to form multi-level micro-nano structure protrusions and use them to penetrate the tiny depressions of the polishing substrate to achieve the purpose of fine finishing.

[0060] In summary, this application provides a novel polishing pad. Firstly, by adding lanthanum oxide to a ceramic binder to refine grains and fill grain boundary defects, and by grafting KH550 into the resin binder to introduce silicon-oxygen functional groups, these groups form chemical bonds with the surface groups of BN-co-doped diamond. Furthermore, BN co-doping enhances the lattice stability of the diamond, thus achieving a synergistic effect and significantly improving the structural stability and heat resistance of the novel polishing pad at high temperatures. Secondly, the novel polishing pad significantly improves the hardness and oxidation resistance of the BN-co-doped diamond through lattice substitution, and the improved composite binder provides sufficient rigidity and toughness, thereby improving the wear resistance of the diamond abrasive. It also works synergistically with multi-level micro / nano-structured nanodiamonds to increase the contact area and reduce diamond abrasive shedding, thereby extending the service life. Simultaneously, the composite binder provides strong cutting force through its ceramic phase, while the resin phase buffers and reduces scratches. The micro / nano-structured nanodiamonds form a gradient cutting edge, effectively assisting in the removal of defects.

[0061] The terms “first,” “second,” “third,” “fourth,” etc., used in this application (if applicable) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, or apparatus.

[0062] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0063] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A novel polishing pad, characterized in that: It comprises 50-70 parts by weight of diamond abrasive, 20-40 parts by weight of composite binder, 0.5-5 parts by weight of auxiliary additives, and 1-20 parts by weight of nanodiamond; the composite binder comprises 65-75% by weight of ceramic binder and 25-35% by weight of resin binder; the ceramic binder contains lanthanum oxide; the diamond abrasive is boron and nitrogen doped BN co-doped diamond.

2. The novel polishing pad according to claim 1, characterized in that: The ceramic binder is composed of silicon dioxide, aluminum oxide, calcium oxide, barium sulfate, and lanthanum oxide in a mass ratio of 30:33-35:14.5-16:14.5-16:4.5-5.

3. The novel polishing pad according to claim 2, characterized in that: The method for preparing the ceramic binder includes step ① mixing silicon dioxide, aluminum oxide, calcium oxide, and barium sulfate, ball milling, and drying to obtain ceramic base powder, and calcining lanthanum oxide to obtain lanthanum oxide; step ② adding the ceramic base powder and lanthanum oxide into deionized water and stirring to obtain a mixed suspension with a solid content of 35-45%, then adding a dispersant accounting for 0.5-0.6% of the solid mass to the mixed suspension, and after ultrasonic dispersion and stirring, spray drying to obtain lanthanum oxide-doped ceramic composite powder; step ③ sintering the ceramic composite powder to remove the dispersant and lanthanum oxide diffusion to obtain modified ceramic binder powder.

4. The novel polishing pad according to claim 3, characterized in that: In step ①, the calcination treatment is carried out at a controlled temperature of 580-600℃ for 2-2.5 hours; in step ②, the dispersant is polyvinylpyrrolidone, and the spray drying treatment is carried out at a controlled inlet air temperature of 180-185℃ and an outlet air temperature of 78-82℃; in step ③, the sintering is carried out by first controlling the heating rate at 5℃ / min to raise the temperature to 580-600℃ and holding it at that temperature for 1-1.2 hours, then controlling the heating rate at 10℃ / min to raise the temperature to 1200-1220℃ and holding it at that temperature for 2-2.1 hours, and finally controlling the cooling rate at 2-5℃ / min to cool down to room temperature.

5. A novel polishing pad according to claim 1, characterized in that: The preparation method of the resin binder includes step ① mixing and stirring 90-100 parts by weight of E51 epoxy resin with 45-50 parts by weight of toluene to obtain an epoxy resin solution; step ② adding 0.9-1% by weight of catalyst to the epoxy resin solution, followed by adding 9.5-10% by weight of KH550 silane coupling agent, and heating to 88-90℃ and holding for 6-6.2 hours after the addition is completed to obtain a silane-grafted epoxy resin mixture; step ③ distilling the silane-grafted epoxy resin mixture under reduced pressure to obtain silane-grafted epoxy resin.

6. A novel polishing pad according to claim 5, characterized in that: In step ②, the catalyst is dibutyltin dilaurate, and the KH550 silane coupling agent is added using a KH550 silane coupling agent solution. The pH of the KH550 silane coupling agent solution is 4-5, and it is obtained by mixing with deionized water at a volume ratio of 1:10 and hydrolyzing for 30-35 minutes. In step ③, the vacuum distillation is carried out by controlling the vacuum degree at -0.09 MPa and the temperature at 98-100℃.

7. A novel polishing pad according to claim 1, characterized in that: The preparation method of BN co-doped diamond includes step ① degassing diamond abrasive at a temperature of 980-1000℃ to obtain pretreated diamond abrasive; step ② mixing the pretreated diamond abrasive with boric acid and melamine at a ratio of 5:1-1.1:1-1.1, and obtaining doped diamond after doping treatment; step ③ cleaning the doped diamond with dilute hydrochloric acid and obtaining BN co-doped diamond after vacuum drying treatment.

8. A novel polishing pad according to claim 7, characterized in that: The doping process includes controlling the pressure at 4.8-5 GPa, the temperature at 1400-1420℃, and the time at 2-2.1 h.

9. A novel polishing pad according to claim 1, characterized in that: The auxiliary additives are 0.15-2 parts of dispersant, 0.25-2.5 parts of binder and 0.1-0.5 parts of defoamer; the dispersant is sodium hexadecyl sulfate or polyvinylpyrrolidone, the binder is water glass or dextrin, and the defoamer is polydimethylsiloxane.

10. A novel polishing pad according to claim 1, characterized in that: The nanodiamond is a hierarchical micro / nanostructured diamond. The preparation method of the hierarchical micro / nanostructured diamond includes the following steps: Step ① Cutting an anodized aluminum template into a specified shape, cleaning it with 5% hydrochloric acid and drying it to obtain a loading template; Step ② Mixing the nanodiamond raw material with deionized water at a ratio of 1g:185-200mL, then adding polyethyleneimine at a volume ratio of 1:4500-5000 with deionized water, ultrasonically dispersing it evenly, and then adding the loading template at a mass ratio of 50-60:1 to the nanodiamond raw material and allowing it to stand for 1-1.2h to obtain the loading template; Step ③ Immersing the loading template in a 10% sodium hydroxide solution, keeping it at a temperature of 48-50℃ for 14-16min, and then drying it to obtain the hierarchical micro / nanostructured diamond.

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