A flexible abrasive and its preparation method

Abstract

This invention belongs to IPC classification number B24D11 / 00, and particularly relates to a flexible abrasive and its preparation method. The flexible abrasive includes a substrate and an abrasive layer pressed onto the substrate. The raw materials of the abrasive layer include, by weight, 50-80 parts of abrasive, 20-45 parts of binder, 1-10 parts of porosimetry agent, and 10-25 parts of thixotropic agent. The binder is a photocurable resin. The use of a photocurable resin in this invention simplifies the preparation method of the flexible abrasive, and the photocurable resin provides good adhesion to the abrasive, further enhancing grinding performance.

Description

Technical Field

[0001] This invention belongs to IPC classification number B24D11 / 00, and particularly relates to a flexible abrasive and its preparation method. Background Technology

[0002] Flexible abrasives are made by adhering abrasive to a flexible substrate with a binder. They are widely used in the surface processing of electronic and automotive parts.

[0003] Patent CN 108188948 Type A multi-layer abrasive belt structure includes a base cloth, a mesh cloth, and an abrasive layer. A base adhesive is applied between the base cloth and the mesh cloth. It has the advantages of high grinding efficiency and the abrasive layer is not easy to fall off. However, the resin reinforcing agent copper powder or iron powder added during its use increases the grinding effect, but it also increases the hardness of the abrasive layer and reduces its toughness. Under long-term external force, cracks will occur. Summary of the Invention

[0004] A flexible abrasive tool includes a substrate and an abrasive layer pressed onto the substrate.

[0005] The substrate is a flexible substrate, including but not limited to cotton paper, cotton cloth, woven fabric, cotton cloth, gauze, polyester-cotton blends or other smooth-surfaced ordinary paper, glass fiber, plastic film, etc.

[0006] The raw materials of the abrasive layer include, by weight, 50-80 parts abrasive, 20-45 parts binder, 1-10 parts pore enhancer, and 10-25 parts thixotropic agent.

[0007] Preferably, the raw materials of the abrasive layer include, by weight, 55-65 parts abrasive, 25-35 parts binder, 5-7 parts pore enhancer, and 12-18 parts thixotropic agent.

[0008] More preferably, the raw materials of the abrasive layer include, by weight, 60 parts abrasive, 30 parts binder, 6 parts pore enhancer, and 15 parts thixotropic agent.

[0009] The abrasive acts as the main abrasive in the abrasive layer. In the embodiments of the present invention, the abrasive is selected from one or more of the following: single crystal corundum, ceramic corundum, high-temperature calcined brown corundum, zirconium corundum, silicon carbide, white corundum, calcined corundum, cerium oxide, silicon oxide, aluminum oxide, silicon nitride, diamond, and boron carbide.

[0010] In some embodiments, the average particle size of the abrasive is greater than 1 μm (for example, greater than 1 μm, greater than 5 μm, greater than 10 μm, greater than 20 μm, greater than 40 μm, greater than 50 μm, greater than 100 μm, or 20 to 100 μm).

[0011] In previous studies, the inventors used resins such as epoxy resin as binders. While these binders exhibited good grinding performance, they required partial curing followed by pressure bonding and room-temperature curing, resulting in a lengthy curing time. Furthermore, poor adhesion between the abrasive layer and the substrate layer was observed during use. In this invention, in some embodiments, the binder is a photocurable resin, selected from one or more of epoxy acrylate resin, polyurethane acrylate resin, polyester acrylate resin, and oligomeric acrylate resin.

[0012] In some preferred embodiments, the photocurable resin is polyurethane acrylate; in some embodiments of the present invention, the raw materials for preparing the polyurethane acrylate resin include, by weight, 20-50 parts of polyurethane acrylate, 10-30 parts of epoxy acrylate, 5-15 parts of reactive diluent, 5-15 parts of acrylate monomer, 1-5 parts of photoinitiator, 0.1-1 parts of coupling agent, and 3-10 parts of inorganic additives.

[0013] More preferably, the raw materials for preparing polyurethane acrylic resin include, by weight, 30-40 parts of polyurethane acrylate, 15-20 parts of epoxy acrylate, 8-12 parts of reactive diluent, 8-12 parts of acrylate monomer, 2-4 parts of photoinitiator, 0.3-0.5 parts of coupling agent, and 6-8 parts of inorganic additives.

[0014] More preferably, the raw materials for preparing polyurethane acrylic resin include, by weight, 35 parts of polyurethane acrylate, 18 parts of epoxy acrylate, 10 parts of reactive diluent, 10 parts of acrylate monomer, 3 parts of photoinitiator, 0.4 parts of coupling agent, and 7 parts of inorganic additives.

[0015] The polyurethane acrylate is a combination of polyether-type polyurethane acrylate and polyester-type polyurethane acrylate, with a weight ratio of (1-5):1, preferably (2-3):1, and more preferably 2.5:1.

[0016] The functionality of the polyether-type polyurethane acrylate is 2 to 3. The polyether-type polyurethane acrylate is commercially available, including but not limited to Sartoma's CN972.

[0017] The polyester-type polyurethane acrylate is commercially available, including but not limited to CN2203NS and CN2270NS from Sartoma.

[0018] The present invention uses the interaction between polyether-type polyurethane acrylate and polyester-type polyurethane acrylate to give the wear-resistant layer good mechanical properties as well as good resistance to damp heat.

[0019] The epoxy acrylate is a bisphenol A epoxy acrylate and / or epoxy soybean oil acrylate resin, preferably epoxy soybean oil acrylate resin, such as Boxin's B-106, DSM's AgiSyn 2020, etc.

[0020] The inventors discovered that adding epoxy acrylate to the system of this invention not only improves the heat resistance of the wear-resistant layer but also increases the adhesion between the abrasive layer and the substrate. This is likely because the addition of epoxy acrylate promotes cross-linking of the system. When mixed with abrasives and pore-forming agents, this cross-linking structure enhances the binder's holding power over the abrasive, thereby improving the system's machinability. However, experiments revealed that the amount of epoxy soybean oil acrylate resin added should not be too high. Excessive amounts can actually reduce the peel strength between the abrasive layer and the substrate. This may be because too much epoxy soybean oil acrylate resin can reduce the stability of the adhesive.

[0021] The inorganic additives are light calcium carbonate, nano-SiO2, silicon dioxide, and calcium sulfate whiskers.

[0022] Preferably, the inorganic additive is a composition of light calcium carbonate and calcium sulfate whiskers, with a weight ratio of 1:(4-6), preferably 1:5.

[0023] The average particle size of the light calcium carbonate is 10-30 μm (preferably 20 μm); the average particle size of the calcium sulfate whiskers is 1-8 μm (preferably 3-5 μm).

[0024] While many commercially available photocurable resins offer good performance and simplify mold preparation, it has been found that abrasives using these resins as binders are prone to cracking and have reduced lifespan. The inventors unexpectedly discovered that adding light calcium carbonate and calcium sulfate whiskers to the photocurable resin system of this invention can extend the lifespan of the abrasives. This is likely because the abrasive and pore-forming agents in this invention are relatively hard materials. During prolonged use, the interaction between the binder, abrasive, and pore-forming agents results in a high-hardness abrasive layer with low toughness attached to the substrate. However, under the action of the coupling agent, calcium sulfate whiskers can form an interfacial film between the abrasive layer and the substrate. Under external force, this interfacial film exhibits stress transfer, thereby increasing the toughness of the abrasive layer. Furthermore, the light calcium carbonate and calcium sulfate whiskers may also enable the binder to form better pores when interacting with the abrasive.

[0025] The reactive diluent is selected from acrylic reactive diluents and / or epoxy reactive diluents.

[0026] Preferably, the acrylic reactive diluent is selected from one of the following reactive diluents: trimethylolpropane triacrylate, triethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, pentaerythritol triacrylate, and tripropylene glycol diacrylate phthalate; more preferably, the acrylic reactive diluent is a combination of trimethylolpropane triacrylate and tripropylene glycol diacrylate phthalate, with a weight ratio of 1:(2-3), preferably 1:2.5.

[0027] In this invention, the polyurethane acrylate, epoxy acrylate and reactive diluent interact with each other, and under the action of ultraviolet light, the double bonds in the system are rapidly cured, thereby achieving adhesion to the substrate.

[0028] The acrylate monomer is a combination of tetrahydrofuran acrylate, isooctyl acrylate and hydroxyethyl methacrylate, in a weight ratio of 1:(2-4):(1.5-3), preferably 1:3:2.

[0029] In this invention, the inventors discovered that using tetrahydrofuran acrylate and isooctyl acrylate can effectively increase the toughness of the abrasive layer. However, the abrasive layer itself has poor resistance to damp heat, possibly because tetrahydrofuran acrylate and isooctyl acrylate are not well compatible. However, the inventors discovered that adding hydroxyethyl methacrylate can better increase the resistance to damp heat of the abrasive layer. This may be because the addition of hydroxyethyl methacrylate promotes the miscibility of the three monomers in the system, ensuring the stability of the binder.

[0030] The photoinitiator is selected from one or more of the following: photoinitiator Irfacure184, photoinitiator Darocure 1173, photoinitiator Irgacure651, photoinitiator Irfacure 2959, and photoinitiator Irfacure 819.

[0031] The coupling agent is a silane coupling agent, including but not limited to KH-550 coupling agent, KH-570 coupling agent, KH-560 coupling agent, etc.

[0032] The preparation method of the polyurethane acrylic resin is as follows: polyurethane acrylate, epoxy acrylate, inorganic additives, reactive diluent, acrylate monomer, photoinitiator, and coupling agent are sequentially added into a double planetary mixer, the vacuum is drawn to a vacuum degree of -0.05 to -0.08 MPa, and the mixture is stirred at 300 to 600 r / min for 1 to 3 hours until it is uniform, and the polyurethane acrylic resin is discharged.

[0033] The pore-forming agent is hollow glass microspheres and / or molecular sieves, preferably hollow glass microspheres.

[0034] The hollow glass microspheres have an average particle size of 80–150 μm and a wall thickness of 1–2 μm.

[0035] The thixotropic agent is selected from at least one of fumed silica, organobentonite, asbestos, and kaolin.

[0036] Preferably, the thixotropic agent is a combination of fumed silica and organobentonite in a weight ratio of 1:(3-5), more preferably 1:4.

[0037] Fumed silica and organobentonite are both commercially available, such as Haiming Sideqian organobentonite BENTONE SD-3 and Degussa fumed silica AEROSIL R805.

[0038] A second aspect of the present invention provides a method for preparing a flexible abrasive, comprising the following steps:

[0039] (1) Mix and stir the raw materials of the abrasive layer to obtain mixture A;

[0040] (2) Apply mixture A into the mold using a scraper;

[0041] (3) The mold and substrate coated with raw materials are placed between two rubber rollers, pressed and cured by ultraviolet light, and finally the mold is peeled off to obtain a flexible mold.

[0042] The shape of the mold can be selected as needed, such as a hemisphere, a semi-ellipsoid, a cone, a pyramid, etc. In some embodiments, the shape of the mold is a pyramid (such as a triangular pyramid, a square pyramid, a pentagonal pyramid, a hexagonal pyramid, etc.).

[0043] In some embodiments, the mold is shaped like a pentagonal pyramid with a base length of 0.1–1 mm and a height of 0.1–1 mm.

[0044] In some embodiments, the coating amount of mixture A in step (2) is 200-350 g / m². 2 .

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] 1. The use of photocurable resin in this invention simplifies the preparation method of flexible molds;

[0047] 2. The specific photocurable resin in this invention reduces the likelihood of chip adhesion to the grinding wheel and causes no damage to the workpiece surface;

[0048] 3. The photocurable resin in this invention has good abrasive holding power, which further enhances the grinding performance;

[0049] 4. This invention reduces the amount of fumed silica used, saving costs, without affecting the performance of flexible abrasives.

[0050] 5. Although a large amount of high-hardness abrasive is used in this invention, the flexible abrasive still has good toughness. Under the action of external force, the abrasive layer will not be easily damaged, thus increasing the service life of the flexible abrasive. Detailed Implementation

[0051] Example 1

[0052] The first aspect of this embodiment provides a flexible abrasive tool, including a substrate and an abrasive layer pressed onto the substrate;

[0053] The raw materials of the abrasive layer include, by weight, 55 parts abrasive, 25 parts binder, 5 parts pore enhancer, and 12 parts thixotropic agent;

[0054] The average particle size of the abrasive is 20 μm; the abrasive is silicon nitride.

[0055] The adhesive is a light-curing resin; the light-curing resin is a polyurethane acrylate resin, and the raw materials for preparing the polyurethane acrylate resin include, by weight, 30 parts polyurethane acrylate, 15 parts epoxy acrylate, 8 parts reactive diluent, 8 parts acrylate monomer, 2 parts photoinitiator, 0.3 parts coupling agent, and 6 parts inorganic additives; the polyurethane acrylate is a combination of polyether-type polyurethane acrylate and polyester-type polyurethane acrylate, with a weight ratio of 2:1; the polyether-type polyurethane acrylate is Sartoma CN972; the polyester-type polyurethane acrylate is Sartoma CN2203NS; the epoxy acrylate is epoxy soybean oil acrylate resin; the epoxy soybean oil acrylate resin is Boxin B-106; the reactive diluent is an acrylic reactive diluent; the acrylic reactive diluent is a combination of trimethylolpropane triacrylate and tripropylene glycol diacrylate phthalate. The weight ratio is 1:2; the acrylate monomer is a combination of tetrahydrofuran acrylate, isooctyl acrylate, and hydroxyethyl methacrylate in a weight ratio of 1:2:2; the photoinitiator is photoinitiator Irfacure184; the coupling agent is KH-560 coupling agent; the inorganic additive is a composition of light calcium carbonate and calcium sulfate whiskers in a weight ratio of 1:4; the average particle size of the light calcium carbonate is 10 μm; the average particle size of the calcium sulfate whiskers is 3 μm; the preparation method of the polyurethane acrylic resin is as follows: polyurethane acrylate, epoxy acrylate, inorganic additive, reactive diluent, reactive diluent, acrylate monomer, photoinitiator, and coupling agent are sequentially added to a double planetary power mixer, the vacuum is drawn to a vacuum degree of -0.05 MPa, and the mixture is stirred at 600 r / min for 3 h until uniform, and the polyurethane acrylic resin is discharged.

[0056] The pore-forming agent is hollow glass microspheres; the average particle size of the hollow glass microspheres is 80 μm and the wall thickness is 1 μm;

[0057] The thixotropic agent is a combination of fumed silica (Degussa AEROSIL R805) and organobentonite (Haimingsideqian organobentonite BENTONE SD-3) in a weight ratio of 1:3.

[0058] The second aspect of this embodiment provides a method for preparing a flexible abrasive, comprising the following steps: (1) mixing and stirring the raw materials of the abrasive layer to obtain a mixture A; (2) applying the mixture A to a mold using a scraper; (3) placing the mold coated with the raw materials and the substrate between two rubber rollers, pressing them together, and curing them under ultraviolet light, and finally peeling off the mold to obtain a flexible abrasive.

[0059] The mold is shaped like a pentagonal pyramid with a base length of 0.4 mm and a height of 0.4 mm; the coating amount of mixture A in step (2) is 200 g / m². 2 The base fabric is a waterproof X-type polyester-cotton blend.

[0060] Example 2

[0061] The first aspect of this embodiment provides a flexible abrasive tool, including a substrate and an abrasive layer pressed onto the substrate;

[0062] The raw materials of the abrasive layer include, by weight, 65 parts abrasive, 35 parts binder, 7 parts pore enhancer, and 18 parts thixotropic agent;

[0063] The abrasive has an average particle size of 100 μm; the abrasive is silicon nitride.

[0064] The adhesive is a photocurable resin; the photocurable resin is a polyurethane acrylate resin, and the raw materials for preparing the polyurethane acrylate resin include, by weight, 40 parts polyurethane acrylate, 20 parts epoxy acrylate, 12 parts reactive diluent, 12 parts acrylate monomer, 4 parts photoinitiator, 0.5 parts coupling agent, and 8 parts inorganic additives; the polyurethane acrylate is a combination of polyether-type polyurethane acrylate and polyester-type polyurethane acrylate, with a weight ratio of 3:1; the polyether-type polyurethane acrylate is Sartoma CN972; the polyester-type polyurethane acrylate is Sartoma CN2270NS; the epoxy acrylate is epoxy soybean oil acrylate resin; the epoxy soybean oil acrylate resin is DSM AgiSyn. 2020; The reactive diluent is an acrylic reactive diluent; the acrylic reactive diluent is a combination of trimethylolpropane triacrylate and tripropylene glycol diacrylate phthalate, with a weight ratio of 1:3; the acrylate monomer is a combination of tetrahydrofuran acrylate, isooctyl acrylate, and hydroxyethyl methacrylate, with a weight ratio of 1:4:3; the photoinitiator is photoinitiator Irfacure184; the coupling agent is KH-570 coupling agent; the inorganic additive is a composition of light calcium carbonate and calcium sulfate whiskers. The weight ratio is 1:6; the average particle size of the light calcium carbonate is 30 μm; the average particle size of the calcium sulfate whiskers is 5 μm; the preparation method of the polyurethane acrylic resin is as follows: polyurethane acrylate, epoxy acrylate, inorganic additives, reactive diluent, reactive diluent, acrylate monomer, photoinitiator, and coupling agent are sequentially added to a double planetary power mixer, the vacuum is drawn to a vacuum degree of -0.08 MPa, and the mixture is stirred at 300 r / min for 1 h until uniform, and the polyurethane acrylic resin is discharged.

[0065] The pore-forming agent is hollow glass microspheres; the average particle size of the hollow glass microspheres is 150 μm and the wall thickness is 2 μm;

[0066] The thixotropic agent is a combination of fumed silica (Degussa AEROSIL R805) and organobentonite (Haimingsideqian organobentonite BENTONE SD-3) in a weight ratio of 1:3.

[0067] The second aspect of this embodiment provides a method for preparing a flexible abrasive, comprising the following steps: (1) mixing and stirring the raw materials of the abrasive layer to obtain a mixture A; (2) applying the mixture A to a mold using a scraper; (3) pressing the mold coated with the raw materials and the substrate between two rubber rollers and curing them under ultraviolet light, and finally peeling off the mold to obtain a flexible abrasive.

[0068] The mold is shaped like a pentagonal pyramid with a base length of 0.5 mm and a height of 0.5 mm; the coating amount of mixture A in step (2) is 350 g / m². 2The base fabric is a waterproof X-type polyester-cotton blend.

[0069] Example 3

[0070] The first aspect of this embodiment provides a flexible abrasive tool, including a substrate and an abrasive layer pressed onto the substrate;

[0071] The raw materials of the abrasive layer include, by weight, 60 parts abrasive, 30 parts binder, 6 parts pore enhancer, and 15 parts thixotropic agent;

[0072] The abrasive has an average particle size of 100 μm; the abrasive is silicon nitride.

[0073] The adhesive is a photocurable resin; the photocurable resin is a polyurethane acrylate resin, and the raw materials for preparing the polyurethane acrylate resin include, by weight, 35 parts polyurethane acrylate, 18 parts epoxy acrylate, 10 parts reactive diluent, 10 parts acrylate monomer, 3 parts photoinitiator, 0.4 parts coupling agent, and 7 parts inorganic additives; the polyurethane acrylate is a combination of polyether-type polyurethane acrylate and polyester-type polyurethane acrylate, with a weight ratio of 2.5:1; the polyether-type polyurethane acrylate is Sartoma CN972; the polyester-type polyurethane acrylate is Sartoma CN2203NS; the epoxy acrylate is epoxy soybean oil acrylate resin; the epoxy soybean oil acrylate resin is DSM AgiSyn. 2020; The reactive diluent is an acrylic reactive diluent; the acrylic reactive diluent is a combination of trimethylolpropane triacrylate and tripropylene glycol diacrylate phthalate, with a weight ratio of 1:2.5; the acrylate monomer is a combination of tetrahydrofuran acrylate, isooctyl acrylate, and hydroxyethyl methacrylate, with a weight ratio of 1:3:2; the photoinitiator is photoinitiator Irfacure184; the coupling agent is KH-570 coupling agent; the inorganic additive is a combination of light calcium carbonate and calcium sulfate whiskers. The materials are in a weight ratio of 1:5; the average particle size of the light calcium carbonate is 20 μm; the average particle size of the calcium sulfate whiskers is 4 μm; the preparation method of the polyurethane acrylic resin is as follows: polyurethane acrylate, epoxy acrylate, inorganic additives, reactive diluent, reactive diluent, acrylate monomer, photoinitiator, and coupling agent are sequentially added to a double planetary power mixer, the vacuum is drawn to a vacuum degree of -0.06 MPa, and the mixture is stirred at 400 r / min for 2 h until uniform, and the polyurethane acrylic resin is discharged.

[0074] The pore-forming agent is hollow glass microspheres; the average particle size of the hollow glass microspheres is 100 μm and the wall thickness is 2 μm;

[0075] The thixotropic agent is a combination of fumed silica (Degussa AEROSIL R805) and organobentonite (Haimingsideqian organobentonite BENTONE SD-3) in a weight ratio of 1:4.

[0076] The second aspect of this embodiment provides a method for preparing a flexible abrasive, comprising the following steps: (1) mixing and stirring the raw materials of the abrasive layer to obtain a mixture A; (2) applying the mixture A to a mold using a scraper; (3) pressing the mold coated with the raw materials and the substrate between two rubber rollers and curing them under ultraviolet light, and finally peeling off the mold to obtain a flexible abrasive.

[0077] The mold is shaped like a pentagonal pyramid with a base length of 0.8 mm and a height of 0.8 mm; the coating amount of mixture A in step (2) is 260 g / m². 2 The base fabric is a waterproof X-type polyester-cotton blend.

[0078] Example 4

[0079] A flexible abrasive and a method for preparing the flexible abrasive are described, with the specific implementation method being the same as in Example 3, except that no inorganic additives are used in the preparation raw materials of the polyurethane acrylic resin.

[0080] Example 5

[0081] A flexible abrasive and a method for preparing the flexible abrasive are described. The specific implementation method is the same as in Example 3, except that the photocurable resin is SM6201 produced by Sanmu Chemical.

[0082] Performance testing

[0083] Abrasive mold samples: The abrasive molds in Examples 1 to 5 were cut into abrasive mold samples of 50mm*2400mm respectively.

[0084] 1. Grinding test

[0085] The 304 stainless steel strip was ground using an SS175-Ⅱ-W type narrow strip grinding test machine and a grinding wheel sample. The grinding conditions were: belt speed 1200m / min and weight mass 6kg.

[0086] Finally, the difference in quality between the stainless steel strip before and after grinding is recorded as the grinding amount.

[0087] 2. Surface condition

[0088] Test method: Clamp one end of the abrasive sample and pull the other end with a force of 50N for 10 minutes. Repeat this 10,000 times and observe whether there are cracks in the abrasive layer of the abrasive sample.

[0089] The test results are shown in Table 1:

[0090] Table 1

[0091]

Claims

1. A flexible abrasive tool, comprising a substrate and an abrasive layer pressed onto the substrate, wherein the substrate is a flexible substrate, characterized in that, The raw materials of the abrasive layer include, by weight, 50-80 parts of abrasive, 20-45 parts of binder, 1-10 parts of pore aid, and 10-25 parts of thixotropic agent; The adhesive is a photocurable resin, which is a polyurethane acrylate resin. The raw materials for preparing the polyurethane acrylate resin include, by weight, 30-40 parts of polyurethane acrylate, 15-20 parts of epoxy acrylate, 8-12 parts of reactive diluent, 8-12 parts of acrylate monomer, 2-4 parts of photoinitiator, 0.3-0.5 parts of coupling agent, and 6-8 parts of inorganic additives. The polyurethane acrylate is a combination of polyether-type polyurethane acrylate and polyester-type polyurethane acrylate, with a weight ratio of (1-5):1; The inorganic additive is a composition of light calcium carbonate and calcium sulfate whiskers, with a weight ratio of 1:(4-6); The acrylate monomer is a combination of tetrahydrofuran acrylate, isooctyl acrylate and hydroxyethyl methacrylate in a weight ratio of 1:(2-4):(1.5-3).

2. The flexible abrasive tool according to claim 1, characterized in that, The abrasive is selected from one or more of the following: single-crystal corundum, ceramic corundum, high-temperature calcined brown corundum, zirconium corundum, silicon carbide, white corundum, calcined corundum, cerium oxide, silicon oxide, aluminum oxide, silicon nitride, diamond, and boron carbide.

3. A flexible abrasive tool according to claim 1 or 2, characterized in that, The average particle size of the abrasive is greater than 1 μm.

4. A flexible abrasive tool according to claim 1, characterized in that, The pore-forming agent is hollow glass microspheres and / or molecular sieves.

5. A flexible abrasive tool according to claim 4, characterized in that, The hollow glass microspheres have an average particle size of 80–150 μm and a wall thickness of 1–2 μm.

6. A flexible abrasive tool according to claim 1, characterized in that, The thixotropic agent is selected from at least one of fumed silica, organobentonite, asbestos, and kaolin.

7. A method for preparing a flexible abrasive according to any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Mix and stir the raw materials of the abrasive layer to obtain mixture A; (2) Apply mixture A into the mold using a scraper; (3) The mold and substrate coated with raw materials are placed between two rubber rollers, pressed and cured by ultraviolet light, and finally the mold is peeled off to obtain a flexible mold.

8. The method for preparing a flexible abrasive according to claim 7, characterized in that, The coating amount of mixture A in step (2) is 200-350 g / m². 2 .

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