A method for preparing a radical-cationic photothermal mixed curing resin and coated abrasive

Abstract

This invention discloses a method for preparing a free radical-cationic photothermal hybrid curing resin and coated abrasives. The resin comprises a primer and a top coat. The preparation steps of the coated abrasive are: primer preparation, primer coating, electrostatic sanding, photocuring the primer, primer preparation, top coat coating, photocuring the top coat, and thermal curing. This invention significantly improves the preparation efficiency and environmental performance of coated abrasives by employing free radical-cationic photothermal hybrid curing technology. Compared to traditional thermocuring resin systems, this technology exhibits excellent energy consumption, as the photocuring process does not require high-temperature heating, greatly reducing energy consumption in production. Since the photocurable resin does not rely on organic solvents and volatile monomers, its use significantly reduces the emission of harmful substances, meeting the requirements of modern industrial green manufacturing.

Description

Technical Field

[0001] This invention relates to the field of coated abrasive manufacturing technology, and more specifically to a free radical-cationic photothermal mixed curing resin and a method for preparing coated abrasives. Background Technology

[0002] In recent years, with increasing environmental awareness and rising energy costs, the problems of high energy consumption, large amounts of organic solvents and volatile monomers, and large production line footprints in traditional coated abrasive manufacturing technologies have become increasingly prominent. Therefore, developing a novel coated abrasive manufacturing technology that can significantly reduce energy consumption, decrease pollution emissions, and optimize production line layout is of significant practical importance. This invention establishes a hybrid curing method based on photocuring technology combined with thermocuring processes, aiming to achieve the above-mentioned goals through technological innovation, while simultaneously improving the overall performance of coated abrasives and meeting the modern industrial demand for high-efficiency, environmentally friendly abrasives.

[0003] In traditional coated abrasive manufacturing, thermosetting resins such as phenolic resins and epoxy resins are widely used. These resins require high temperatures and long curing times, leading to a significant increase in energy consumption. Furthermore, the production of thermosetting resins typically involves the use of large amounts of organic solvents and volatile monomers, causing serious environmental pollution and posing a threat to the health of operators. At the same time, thermosetting resin production lines often require large floor space, and the long curing times and complex processes further increase production costs and equipment investment.

[0004] In recent years, photopolymerization technology, as an emerging curing method, has gradually gained attention in the field of coated abrasives. Photopolymerization technology uses ultraviolet or visible light to initiate resin curing, offering advantages such as high efficiency, energy saving, and environmental friendliness. However, the application of photopolymerization technology in coated abrasives still faces certain limitations. For example, a single photopolymerization mechanism is insufficient to meet the multiple requirements of coated abrasives for mechanical strength and wear resistance, and the limited curing depth restricts its application in coarse-grained abrasives.

[0005] Therefore, developing a novel method for preparing coated abrasives that combines the advantages of photocuring and thermocuring has become an urgent problem for those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a free radical-cationic photothermal hybrid curing technology for preparing coated abrasives, overcoming the shortcomings of traditional thermosetting resins in terms of energy consumption, environmental pollution, and production line layout. In this invention, the primer is initially cured by ultraviolet light irradiation, followed by thermal curing for final curing. The top coat is fully cured by ultraviolet light curing. The solution of this invention significantly reduces energy consumption in production, reduces the use of organic solvents and volatile monomers, while optimizing the production line layout and improving the overall performance of the coated abrasives.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A free radical-cationic photothermal hybrid curing resin, consisting of a primer and a top coat; The primer comprises the following raw materials in parts by weight: 20-60 parts of difunctional polyurethane acrylate, 10-30 parts of polyfunctional polyurethane acrylate, 2-30 parts of aliphatic epoxy resin, 0.2-3 parts of free radical initiator, 0.1-3 parts of cationic initiator, 0.05-6 parts of curing agent and chain transfer agent, and 2-30 parts of reactive diluent; The adhesive comprises the following raw materials in parts by weight: 20-80 parts epoxy acrylate, 10-30 parts multifunctional polyurethane acrylate, 1-5 parts free radical photoinitiator, and 2-30 parts reactive diluent.

[0009] Preferably, the mass ratio of difunctional polyurethane acrylate to polyfunctional polyurethane acrylate in the base adhesive is 1:1 to 3:1.

[0010] This invention uses a primer coating machine on a coating abrasive production line to uniformly roll-coat the base fabric or film substrate, ensuring the uniformity and consistency of the coating.

[0011] Furthermore, the difunctional polyurethane acrylate in the base adhesive is any one or a mixture of toluene diisocyanate-based polyurethane diacrylate (TDI-PUA), diphenylmethane diisocyanate-based polyurethane diacrylate (MDI-PUA), hexamethylene diisocyanate-based polyurethane diacrylate (HDI-PUA), isophorone diisocyanate-based polyurethane diacrylate (IPDI-PUA) or dicyclohexylmethane diisocyanate-based polyurethane diacrylate (HMDI-PUA); The multifunctional polyurethane acrylate is any one or a mixture of trifunctional polyurethane acrylate (TMPTA-PUA), tetrafunctional polyurethane acrylate (PETA-PUA), or hexafunctional polyurethane acrylate. The aliphatic epoxy resin is any one or a mixture of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, bis(3,4-epoxycyclohexylmethyl) adipate, or dicyclopentadiene dioxide.

[0012] The aliphatic epoxy resin used in this invention can improve the curing depth and bonding strength of the adhesive layer. This invention initiates polymerization through a cationic photoinitiator and takes advantage of the characteristics of cationic reactions being difficult to terminate and easy to transfer. By adding a special chain transfer agent, a certain cationic concentration is maintained in the system, thereby enhancing the adhesion and chemical resistance of the primer.

[0013] The combination of the above three resins in this invention can effectively improve the overall performance of the adhesive in coated abrasives. The difunctional polyurethane acrylate provides flexibility, the multifunctional polyurethane acrylate increases the crosslinking density of the polyurethane and the peel strength of the adhesive, while the aliphatic epoxy resin is suitable for cationic photocuring, which increases the depth of the cured layer and improves the bonding strength. The comparison results are shown in Table 1.

[0014] Table 1. Effect of different adhesive matrix resin formulations on material properties

[0015] Note: 1. In the table, TDI-PUA is toluene diisocyanate-based polyurethane diacrylate, PETA-PUA is tetrafunctional polyurethane acrylate, and S-28 is bis(3,4-epoxycyclohexylmethyl) adipate or dicyclopentadiene dioxide; 2. The abrasive cloth is 120-mesh white corundum, and the grinding object is 45# steel.

[0016] Furthermore, the free radical photoinitiator in the primer is any one of the following: 1173 photoinitiator (2-hydroxy-2-methyl-1-phenylpropanone), 184 photoinitiator (1-hydroxycyclohexylphenyl ketone), 907 photoinitiator (2-methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone), TPO photoinitiator (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), and TPO-L photoinitiator (ethyl 2,4,6-trimethylbenzoylphenylphosphonate). The cationic photoinitiator is any one of diaryliodonium, triarylthionium salt, and ferrocene salt; Preferably, the diaryliodomonium salt is Irgacure 250 (CAS: 344562-80-7) or bis(4-tert-butylphenyl)iodomonium hexafluorophosphate (CAS: 61358-25-6) 12; the triarylsulfonium salt is Chivacure® 1176 (CAS: 71449-78-0) triphenylsulfonium tetrafluoroborate (CAS: 437-13-8); and the ferrocene salt (iron aromatic salt) is Irgacure 261 (CAS: 32760-80-8, i.e. (isopropylbenzene)cyclopentadienyl iron(II) hexafluorophosphate).

[0017] In this invention, the addition of free radical photoinitiators and cationic photoinitiators is used to initiate free radical polymerization and cationic polymerization reactions, respectively, thereby achieving a synergistic effect of the dual curing mechanism. The role of the curing agent and chain transfer agent is to regulate the growth process of molecular chains and avoid increased brittleness caused by excessive crosslinking.

[0018] The curing agent and chain transfer agent is a thiol substance; Preferably, the thiol is any one of pentaerythritol tetrakis(3-mercaptopropionic acid) ester (PETMP), glycerol 3-thiopropionate (TMPMP), and pentaerythritol tetrakis(3-mercaptobutyrate).

[0019] In this invention, the active hydrogen in thiols can react with excess free radicals. After hydrogen is abstracted from the thiols, new free radicals are formed and continue to participate in the reaction, which can significantly promote the depth of photocuring and improve the adhesion, toughness, and double bond conversion rate of the cured system. As a UV curing aid / curing agent, it can improve oxygen inhibition, enhance deep / dark curing, increase adhesion to the substrate, and reduce the energy required for curing. Simultaneously, it can be used as a curing agent / curing aid for epoxy resins to accelerate the curing speed, lower the curing temperature, and improve the flexibility of the cured product.

[0020] The reactive diluent is one or a mixture of two of the following: a difunctional acrylate diluent and a vinyl ether diluent.

[0021] Preferably, the difunctional acrylate diluent is polyethylene glycol diacrylate, dipropylene glycol diacrylate, or neopentyl glycol diacrylate.

[0022] Preferably, the vinyl ether diluent is triethylene glycol divinyl ether (DVE-3) or 1,4-butanediol divinyl ether.

[0023] The addition of the reactive diluent in this invention helps to adjust the viscosity of the system and improve the workability. The vinyl ether used can participate in cationic polymerization and can also be used in free radical systems, with the advantages of fast reaction speed, low toxicity and low odor.

[0024] Furthermore, the epoxy acrylate in the adhesive is any one or a mixture of bisphenol A epoxy acrylate, bisphenol A epoxy acrylate, and epoxy soybean oil acrylate; In this invention, epoxy acrylate and multifunctional polyurethane acrylate are the main components, which can form a network structure with high cross-linking density, thereby enhancing the wear resistance and sharpness of the abrasive.

[0025] Furthermore, the free radical photoinitiator mentioned in the composite adhesive is any one of the following: 1173 photoinitiator (2-hydroxy-2-methyl-1-phenylpropanone), 184 photoinitiator (1-hydroxycyclohexylphenyl ketone), 907 photoinitiator (2-methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone), TPO photoinitiator (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), and TPO-L photoinitiator (ethyl 2,4,6-trimethylbenzoylphenylphosphonate). The active diluent is a vinyl ether diluent, preferably triethylene glycol divinyl ether (DVE-3) or 1,4-butanediol divinyl ether.

[0026] This invention also provides a method for preparing coated abrasives, using the above-mentioned free radical-cationic photothermal mixed curing resin, comprising the following steps: (1) Preparation of primer: The difunctional polyurethane acrylate, polyfunctional polyurethane acrylate, aliphatic epoxy resin in the primer are mixed evenly with free radical initiator, cationic initiator, curing agent, chain transfer agent and reactive diluent to form primer. (2) Applying primer: Apply primer to the substrate; (3) Electrostatic sand planting: Electrostatic sand planting is used to implant abrasives into a substrate coated with primer; (4) UV-cured primer: The primer is cured by irradiation with ultraviolet light to achieve initial curing; (5) Preparation of composite adhesive: The epoxy acrylate, multifunctional polyurethane acrylate, free radical initiator and reactive diluent in the composite adhesive are mixed evenly to form a composite adhesive; (6) Coating with adhesive: Applying adhesive by roller to the substrate on which abrasive has been implanted; (7) UV-cured adhesive: The adhesive is cured by UV irradiation to achieve initial curing; (8) Complete thermal curing: The substrate is thermally cured to achieve the final complete curing of the coated abrasive.

[0027] Furthermore, the substrate mentioned in step (2) is a raw fabric or a film; The abrasive mentioned in step (3) is any one of white corundum, green silicon carbide, cubic boron nitride and diamond with ceramic or resin coating on the surface, and the particle size of the abrasive is 100 mesh or finer (can pass through a 100 mesh sieve).

[0028] The abrasive used in this invention possesses high hardness and wear resistance, making it suitable for the precision machining needs of various workpieces. Furthermore, due to the limited depth of UV curing, the abrasive particle size must be controlled to be finer than 100 mesh to ensure sufficient bonding between the abrasive and the primer during the curing process. Compared to traditional gravity-based abrasive application, electrostatic abrasive application is suitable for fine-grained abrasives and can significantly improve the regularity of abrasive particle arrangement and the proportion of sharp points facing outwards, thereby enhancing the sharpness and wear resistance of the abrasive tool.

[0029] Furthermore, the light source for photocuring in step (4) is a mercury lamp or a UV LED, with an ultraviolet wavelength range of 200-450nm and a light source power of 50-120W / cm². 2 The curing time is 1~10 min.

[0030] Furthermore, the light source for photocuring in step (7) is a mercury lamp or a UV LED, with an ultraviolet wavelength range of 200-450nm and a light source power of 50-120W / cm². 2 The curing time is 1~10 min.

[0031] Preferably, the curing method in steps (4) and (7) is to use a staged irradiation method, first performing low-intensity, short-time pre-curing with an ultraviolet light intensity of 50~80 W / cm². 2 Irradiate for 1-2 minutes, then use a high-intensity light source of 100-120 W / cm². 2 Irradiation for 2-5 minutes allows the adhesive to fully cure, thus preventing cracks from forming on the surface of the adhesive due to rapid curing.

[0032] To overcome the oxygen inhibition effect during the curing process, inert gas protection or the addition of antioxidants can be employed. The above-described solution of this invention enables rapid and uniform photocuring of the primer, laying a solid foundation for subsequent topcoat application.

[0033] Furthermore, the heat curing in step (8) is carried out by electric heating or steam heating, with a heat curing temperature of 120-150℃ and a heat curing time of 30-60min.

[0034] In the above-described embodiment of the present invention, the unreacted functional groups can undergo further polymerization to form a denser three-dimensional network structure. The necessity of thermosetting lies in the fact that relying solely on photocuring may not achieve deep curing, while thermosetting effectively compensates for this deficiency, ensuring that the coated abrasive exhibits excellent mechanical properties and durability during use.

[0035] Furthermore, the coating thickness of the base adhesive is 70-200 μm, and the coating thickness of the top adhesive is 20-60 μm.

[0036] The beneficial effects of this invention are as follows: By employing a free radical-cationic photothermal hybrid curing technology, this invention significantly improves the preparation efficiency and environmental performance of coated abrasives. Compared to traditional thermosetting resin systems, this technology exhibits superior energy consumption, as the photocuring process does not require high-temperature heating, greatly reducing energy consumption in production. Furthermore, since the photocurable resin does not rely on organic solvents and volatile monomers, its use significantly reduces the emission of harmful substances, meeting the requirements of modern industrial green manufacturing.

[0037] In terms of production line layout, the introduction of photocuring technology optimizes the production line length and floor space, overcoming the drawbacks of traditional thermocuring processes that require prolonged heating and cooling, thereby improving the utilization rate of production space. Overall, this invention not only solves many problems in traditional coated abrasive manufacturing but also significantly improves the overall performance of the products, providing a new direction for technological advancement in the coated abrasive industry. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the preparation process of the coated abrasive of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1 (1) In the primer, difunctional polyurethane acrylate (PUA-2) and hexafunctional polyurethane acrylate (PUA-6) are selected as the main film-forming substances. Aliphatic epoxy resin (bis(3,4-epoxycyclohexylmethyl) adipate or dicyclopentadiene dioxide) is used to enhance the flexibility and adhesion of the primer. The free radical initiator is Omnraid1173D (2-hydroxy-2-methyl-1-phenyl-1-propanone), the cationic initiator is Irgacure 261 ((isopropylbenzene)cyclopentadienyl iron(II) hexafluorophosphate), the curing agent and chain transfer agent is glycerol 3-thiopropionate (TMPMP), and the reactive diluent is a 1:1 mixture of polyethylene glycol diacrylate and triethylene glycol divinyl ether (DVE-3). The above raw materials for the primer are mixed evenly in a mass ratio of 40:30:20:3:2:5:10. (2) The primer is applied to the polyester film substrate by roller coating machine on the coated abrasive production line, with a coating thickness of 200μm. Then, 120-mesh white corundum abrasive is uniformly implanted into the primer layer using electrostatic sand planting technology.

[0041] (3) During the UV curing process of the primer, a mercury lamp UV light source with a wavelength of 365nm is used, and the UV light intensity is initially set to a low power of 80 W / cm². 2 Irradiate for 2 minutes, then use high power 120 W / cm 2 Irradiate for 3 minutes to ensure the primer is fully cured.

[0042] (4) Epoxy acrylate (EA) and polyurethane acrylate (PUA-M) are selected as the main components in the adhesive. Free radical initiator 1173D and reactive diluent DVE-3 are added and mixed evenly at a mass ratio of 50:30:5:15. The adhesive is then coated onto the sand roll that has been planted with sand, and the coating thickness is 50μm.

[0043] (5) The curing conditions for the top coat are the same as those for the base coat, and the irradiation time is 3 min. Finally, the coating abrasive is completely cured by a thermosetting process at 120℃ for 2 h, and a photocurable resin abrasive cloth roll is prepared.

[0044] Tests showed that the grinding performance of the obtained white fused alumina resin abrasive discs was basically equivalent to that of traditional thermosetting coated abrasives, and the energy consumption in the production process was reduced by 70%, while the emissions of organic solvents and volatile monomers were reduced by more than 80%, which significantly optimized the production environment and improved product performance.

[0045] Example 2 (1) In the primer, tetrafunctional polyurethane acrylate (PUA-4) is selected as the main film-forming substance. The aliphatic epoxy resin is selected as bis(3,4-epoxycyclohexylmethyl) adipate or dicyclopentadiene dioxide to enhance the flexibility and adhesion of the primer. The free radical initiator is selected as TPO, the cationic initiator is selected as triphenylsulfonium tetrafluoroborate, the curing agent and chain transfer agent is selected as pentaerythritol tetrakis(3-mercaptopropionic acid) (PETMP), and the reactive diluent is selected as triethylene glycol divinyl ether (DVE-3). The raw materials are mixed in a mass ratio of 50:30:3:2:5:10.

[0046] (2) The primer is applied to the polyester film substrate by roller coating machine on the coated abrasive production line, with a coating thickness of 75μm. Then, the diamond with W20 particle size and surface resin coating is uniformly implanted into the primer layer using electrostatic sand planting technology.

[0047] (3) During the UV curing process of the primer, a mercury lamp UV light source with a wavelength of 365nm is used, and the UV light intensity is initially set to a low power of 80 W / cm². 2 Irradiate for 2 minutes, then use high power 120 W / cm 2 Irradiate for 3 minutes to ensure the primer is fully cured.

[0048] (4) Epoxy acrylate (EA) and polyurethane acrylate (PUA-M) are selected as the main components in the adhesive. Free radical initiator TPO and reactive diluent triethylene glycol divinyl ether (DVE-3) are added and mixed evenly at a mass ratio of 50:30:5:15. The adhesive is then coated onto the sand roll that has been planted with sand, and the coating thickness is 30μm.

[0049] (5) The curing conditions for the top coat are the same as those for the base coat, and the irradiation time is 3 min. Finally, the coating abrasive is completely cured by a thermosetting process at 120℃ for 2 h, and a photocurable resin abrasive cloth roll is prepared.

[0050] Tests showed that the diamond abrasive belts produced had a grinding performance that was more than 300% better than SiC abrasive paper, and reduced energy consumption by 40% and emissions of organic solvents and volatile monomers by more than 80%, significantly optimizing the production environment and improving product performance.

[0051] Table 2 Comparison of energy consumption, VOC emissions, and grinding performance of coated abrasives in Examples 1-2

[0052] Note: The processing objects in Examples 1 and Comparative Example 2 are stainless steel; the processing objects in Examples 2 and Comparative Example 2 are monocrystalline silicon.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A free radical-cationic photothermal hybrid curing resin, characterized in that, It consists of a base coat and a top coat; The primer comprises the following raw materials in parts by weight: 20-60 parts of difunctional polyurethane acrylate, 10-30 parts of polyfunctional polyurethane acrylate, 2-30 parts of aliphatic epoxy resin, 0.2-3 parts of free radical initiator, 0.1-3 parts of cationic initiator, 0.05-6 parts of curing agent and chain transfer agent, and 2-30 parts of reactive diluent; The adhesive comprises the following raw materials in parts by weight: 20-80 parts epoxy acrylate, 10-30 parts multifunctional polyurethane acrylate, 1-5 parts free radical photoinitiator, and 2-30 parts reactive diluent.

2. The free radical-cationic photothermal hybrid curing resin according to claim 1, characterized in that, The difunctional polyurethane acrylate in the base adhesive is any one or a mixture of toluene diisocyanate-based polyurethane diacrylate, diphenylmethane diisocyanate-based polyurethane diacrylate, hexamethylene diisocyanate-based polyurethane diacrylate, isophorone diisocyanate-based polyurethane diacrylate, or dicyclohexylmethane diisocyanate-based polyurethane diacrylate. The multifunctional polyurethane acrylate is any one or a mixture of trifunctional polyurethane acrylate, tetrafunctional polyurethane acrylate, or hexafunctional polyurethane acrylate. The aliphatic epoxy resin is any one or a mixture of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, bis(3,4-epoxycyclohexylmethyl) adipate, or dicyclopentadiene dioxide.

3. The free radical-cationic photothermal hybrid curing resin according to claim 1 or 2, characterized in that, The free radical photoinitiator mentioned in the primer is any one of 1173 photoinitiator, 184 photoinitiator, 907 photoinitiator, TPO photoinitiator, and TPO-L photoinitiator.

4. The free radical-cationic photothermal hybrid curing resin according to claim 1, characterized in that, The cationic photoinitiator is any one of diaryliodomonium salt, triarylthionium salt, and ferrocene salt; the curing agent and chain transfer agent is a thiol substance. The reactive diluent is one or a mixture of two of the following: a difunctional acrylate diluent and a vinyl ether diluent.

5. The free radical-cationic photothermal hybrid curing resin according to claim 1, characterized in that, The epoxy acrylate in the coating is any one or a mixture of bisphenol A epoxy acrylate, bisphenol A epoxy acrylate and epoxy soybean oil acrylate.

6. A method for preparing a coated abrasive, characterized in that, The method using the free radical-cationic photothermal hybrid curing resin according to any one of claims 1-5 includes the following steps: (1) Preparation of primer: The difunctional polyurethane acrylate, polyfunctional polyurethane acrylate, aliphatic epoxy resin in the primer are mixed evenly with free radical initiator, cationic initiator, curing agent, chain transfer agent and reactive diluent to form primer. (2) Applying primer: Apply primer to the substrate; (3) Electrostatic sand planting: Electrostatic sand planting is used to implant abrasives into a substrate coated with primer; (4) UV-cured primer: The primer is cured by irradiation with ultraviolet light to achieve initial curing; (5) Preparation of composite adhesive: The epoxy acrylate, multifunctional polyurethane acrylate, free radical initiator and reactive diluent in the composite adhesive are mixed evenly to form a composite adhesive; (6) Coating with adhesive: Applying adhesive by roller to the substrate on which abrasive has been implanted; (7) UV-cured adhesive: The adhesive is cured by UV irradiation to achieve initial curing; (8) Complete thermal curing: The substrate is thermally cured to achieve the final complete curing of the coated abrasive.

7. The method for preparing a coated abrasive according to claim 6, characterized in that, The substrate mentioned in step (2) is a raw fabric or a film; The abrasive mentioned in step (3) is any one of white corundum, green silicon carbide, cubic boron nitride, and diamond with ceramic or resin coating on the surface, and the particle size of the abrasive is 100 mesh or finer.

8. The method for preparing a coated abrasive according to claim 6, characterized in that, The light source for photocuring in step (4) is a mercury lamp or a UV LED, with a UV wavelength range of 200-450nm and a light source power of 50-120W / cm². 2 The curing time is 1~10 min.

9. The method for preparing a coated abrasive according to claim 6, characterized in that, The light source for photocuring in step (7) is a mercury lamp or a UV LED, with a UV wavelength range of 200-450nm and a light source power of 50-120W / cm². 2 The curing time is 1~10 min.

10. The method for preparing a coated abrasive according to claim 6, characterized in that, The thermosetting temperature in step (8) is 120-150℃ and the thermosetting time is 30-60min.

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