Sheet-like abrasive article

Abstract

Provided is a long-life sheet-shaped abrasive article in which closed-cell bubbles in an abrasive material layer not only provide air holes for chip discharge in the abrasive material layer but also ensure a space between a surface of the abrasive material layer and a cutting material, thereby making chip discharge of the cutting material easy, and new abrasive grains act on the cutting material while the closed-cell bubbles of the surface layer of the abrasive material layer are damaged due to friction generated in the grinding operation, thereby the abrasive material layer having self-dressing property. An abrasive article characterized by being a sheet-shaped abrasive article provided with a base material and an abrasive material layer provided on one surface of the base material, the abrasive material layer containing closed-cell bubbles, first abrasive grains, and a first adhesive binder, the closed-cell bubbles having an inner diameter of 30 μm to 200 μm, the first abrasive grains having an average particle diameter of one-third or less of the inner diameter of the closed-cell bubbles, the first adhesive binder bonding the abrasive material layer to the base material, the closed-cell bubbles accounting for 70 vol% to 85 vol%, the first abrasive grains accounting for 5 vol% to 13 vol%, and the first adhesive binder accounting for the balance, based on the volume of the entire abrasive material layer.

Description

Technical Field

[0001] This invention relates to sheet-shaped abrasive articles. In particular, it relates to sheet-shaped abrasive articles suitable for grinding coatings to achieve a mirror finish or a roughness just before a mirror finish is formed. The sheet-shaped abrasive articles of this invention are not limited to industrial grinding and polishing processes, but can also be effectively used in cleaning applications such as removing scale defects from metal and IH heater surfaces, bathroom ceramics, and glass surfaces. Background Technology

[0002] To achieve a mirror finish on the surface of an item, or just before that finish, polishing films (abrasive materials) are typically used as precision grinding products. However, in the case of grinding to achieve this finish with a coated film, sufficient grinding force cannot be obtained using polishing films. Therefore, polishing films are rarely used in the market for mirror finishing of coated films.

[0003] In the market for polishing coated films to a mirror finish, most use is 3M's Trizact abrasive material. Trizact abrasive material is touted as employing a technology called "microreplication." Specifically, Trizact abrasive material is claimed to feature a regular micro-replicated structure that prevents deformation due to heat and enables stable finishing, achieving a consistent polishing rate. Furthermore, it is claimed that the three-dimensional structure creates new abrasive grains, resulting in continuous uniform finishing, preventing dressing, and causing abrasive debris to fall into the gaps of the three-dimensional surface structure, thus reducing clogging and maintaining consistent polishing performance.

[0004] However, in practice, it is extremely difficult for the molded abrasive material used in the pyramidal structure as Trizact to completely wear out. Therefore, products with a longer lifespan compared to Trizact are expected.

[0005] Patent document 1 discloses an abrasive material containing a cured thermosetting resin powder, comprising: a porous body having multiple bubbles derived from thermally expandable microspheres, and abrasive particles dispersed in the aforementioned porous body.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2018-103342 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The object of the present invention is to provide a sheet-shaped abrasive article in which the abrasive material layer comprises: closed-cell air bubbles having a predetermined inner diameter, and abrasive grains having an average particle size that is in a predetermined relationship with the inner diameter of the closed-cell air bubbles. Furthermore, the volume ratio of the closed-cell air bubbles to the abrasive grains in the abrasive material layer is within a predetermined range. Thus, the closed-cell air bubbles in the abrasive material layer of the sheet-shaped abrasive article not only provide pores for chip removal within the abrasive material layer, but also ensure space between the surface of the abrasive material layer (or the surface of the top coating layer if a thin top coating is provided on the abrasive material layer) and the cutting material, thereby facilitating the removal of chips from the cutting material. Additionally, the object of the present invention is to provide a long-life sheet-shaped abrasive article in which the abrasive grains of the abrasive material layer containing closed-cell air bubbles exist on the wall surface of the closed-cell air bubbles. While the closed-cell air bubbles on the surface of the abrasive material layer are damaged due to friction generated during the abrasive operation, new abrasive grains act on the cutting material, thereby giving the abrasive material layer self-dressing properties.

[0011] Solution for solving the problem

[0012] That is, the present invention is an abrasive article, characterized in that it is a sheet-shaped abrasive article having a substrate and an abrasive material layer disposed on one side of the substrate. The abrasive material layer contains closed-cell bubbles, a first abrasive grain, and a first adhesive. The inner diameter of the closed-cell bubbles is 30 μm to 200 μm, the average particle size of the first abrasive grain is less than one-third of the inner diameter of the closed-cell bubbles, and the first adhesive binds the abrasive material layer to the substrate. Taking the overall volume of the abrasive material layer as a reference, the closed-cell bubbles account for 70% to 85% of the volume, the first abrasive grain accounts for 5% to 13% of the volume, and the first adhesive accounts for the remainder.

[0013] The abrasive article of the present invention can be configured such that it further comprises a top coating layer disposed on the side of the aforementioned abrasive material layer opposite to the side that contacts the aforementioned substrate, the aforementioned top coating layer containing a second abrasive grain, a second adhesive and a metal soap, the aforementioned second adhesive bonding the aforementioned top coating layer to the aforementioned abrasive material layer.

[0014] In the abrasive articles of the present invention, the aforementioned closed-cell air bubbles are preferably derived from thermally expandable microcapsules.

[0015] Furthermore, in the abrasive article of the present invention, the aforementioned first adhesive is preferably a photocurable resin.

[0016] The abrasive article of the present invention can be configured such that it further comprises a buffer material layer disposed on the side of the aforementioned substrate opposite to the side that contacts the aforementioned abrasive material layer.

[0017] In this case, it is preferable that the aforementioned buffer material layer is sponge.

[0018] Furthermore, the abrasive article of the present invention can be configured such that it further comprises an adhesive material layer disposed on the side of the aforementioned substrate opposite to the side that contacts the aforementioned abrasive material layer (the inner side of the abrasive working surface of the abrasive article). Additionally, it can be configured such that an adhesive layer is further disposed on the inner side of the abrasive working surface of the abrasive article having the aforementioned buffer material layer.

[0019] The abrasive article of the present invention may also be configured such that it further comprises an engaging member layer disposed on the side of the aforementioned substrate opposite to the side that contacts the aforementioned abrasive material layer. Alternatively, it may be configured such that an engaging member layer is further disposed on the inner side of the abrasive action surface of the abrasive article having the aforementioned buffer material layer.

[0020] In this case, it is preferable that the aforementioned locking component layer is hook and loop fastener.

[0021] The effects of the invention

[0022] According to the present invention, closed-cell air bubbles in the abrasive material layer provide pores in the abrasive material layer and ensure the space between the surface of the abrasive material layer and the cutting material, thereby obtaining a sheet-shaped abrasive article with excellent chip removal performance and self-compensating properties due to the large number of closed-cell air bubbles present in the abrasive material layer. The sheet-shaped abrasive article of the present invention has efficient abrasive workability and a large abrasive processing area per unit area of ​​abrasive material. Attached Figure Description

[0023] Figure 1 This is an enlarged cross-sectional schematic diagram of one embodiment of the sheet-like abrasive article of the present invention.

[0024] Figure 2 This is an enlarged cross-sectional view of another embodiment of the sheet-like abrasive article of the present invention. Detailed Implementation

[0025] The embodiments of the present invention will be described below.

[0026] (Substrate)

[0027] The substrate used in the sheet-like abrasive article of the present invention can be a polyester film, latex-impregnated paper, latex-barrier paper, a combination thereof, or a substrate formed by surface treatment of the thereof. For example, when using a polyester film substrate as the substrate, a polyester film substrate with improved adhesion through an easy-adhesion treatment can be appropriately used.

[0028] The thickness of the substrate can be 25~500μm, preferably 50~220μm.

[0029] (Abrasive material layer)

[0030] The abrasive material layer of the sheet-like abrasive article of the present invention contains closed-cell air bubbles, a first abrasive grain, and a first adhesive.

[0031] From the viewpoint that the abrasive article of the present invention is in sheet form, the thickness of the abrasive material layer formed on the substrate is preferably 400 μm or less.

[0032] (Closed-cell air bubble)

[0033] As closed-cell bubbles, hollow capsules, specifically phenol hollow capsules, glass hollow capsules, and acrylonitrile thermally expandable hollow capsules can be used. Among them, acrylonitrile thermally expandable capsules (thermally expandable microcapsules) are particularly preferred because the capsules before expansion have relatively high strength when preparing the coating liquid for the abrasive material layer during the manufacturing process, making operation easier. Furthermore, the specific gravity of the capsules before expansion is not significantly different from that of other raw materials in the abrasive material layer, allowing for uniform mixing and stirring of the raw materials used to prepare the coating liquid for the abrasive material layer. This facilitates the uniform distribution of closed-cell bubbles in the abrasive material layer.

[0034] The inner diameter of the closed-cell bubble (referring to the pore size in the abrasive material layer; in the case of a closed-cell bubble originating from a thermally expanded bladder, it corresponds to the inner diameter of the fully expanded bladder) is 30 μm to 200 μm. When the inner diameter of the closed-cell bubble is 30 μm or less, it is considered difficult to form sufficient space for removing chips generated during grinding. On the other hand, from the viewpoint of stabilizing the strength of the abrasive material layer, the inner diameter of the closed-cell bubble is preferably less than half the thickness of the abrasive material layer. As mentioned above, the thickness of the abrasive material layer is preferably 400 μm or less, therefore the upper limit of the inner diameter of the closed-cell bubble is 200 μm. The inner diameter of the closed-cell bubble is preferably 50 μm to 150 μm. The inner diameter of the closed-cell bubble can be measured using a digital microscope (e.g., a KEYENCE VHX-6000 digital microscope).

[0035] The inner diameter of the closed-cell bubble is more than three times the average particle size of the abrasive grains used (in other words, the average particle size of the abrasive grains is less than one-third of the inner diameter of the closed-cell bubble).

[0036] The reason for setting the average particle size of the abrasive grains to less than one-third of the inner diameter of the closed-cell bubble is that when the abrasive material layer is coated and the thermal expansion bladder is expanded, if the average particle size of the abrasive grains exceeds one-third of the inner diameter of the closed-cell bubble, the presence of abrasive grains around the thermal expansion bladder will easily cause deviation.

[0037] The average particle size of abrasive grains can be measured, for example, by resistance testing (refer to JIS R 6001-2:2017).

[0038] (Abrasive grains)

[0039] As described above, the average particle size of the abrasive grains (first abrasive grains) in the abrasive material layer is less than one-third of the inner diameter of the closed-cell bubble.

[0040] The abrasive grains in the abrasive material layer can appropriately be abrasive grains with an average particle size of 0.3 μm to 46 μm. The average particle size can be determined using, for example, the electrical resistance method as a particle size determination method.

[0041] Abrasive grains used as abrasive material layers can be used alone or in combination, and can be composed of diamond, cubic boron nitride, alumina, silicon carbide, cerium oxide, and silicon dioxide.

[0042] (Adhesive)

[0043] As a bonding agent for the abrasive material layer (first bonding agent), there are no particular limitations if it can bond the abrasive material layer to the substrate. Examples include photocurable acrylic resins, photocurable epoxy resins, photocurable polyurethane resins, thermosetting epoxy resins, thermosetting phenolic resins, thermosetting polyurethane resins, ethylene vinyl acetate resins, polyethylene resins, polyvinyl chloride resins, polypropylene resins, acrylonitrile butadiene styrene copolymer resins, and ethylene propylene rubber.

[0044] When using closed-cell bubbles, such as thermally expandable microcapsules (acrylonitrile thermally expandable capsules, etc.), a photocurable adhesive is preferred as the bonding agent used in conjunction with them. This is because, after the thermally expandable capsule has expanded, the adhesive can be cured by photocuring at any time, making it easy to achieve an abrasive material layer containing closed-cell bubbles, abrasive particles, and adhesive in the pre-designed (volume) ratio. Of course, if a thermoplastic resin or a thermosetting resin is required as the adhesive, the thermally expandable capsule and adhesive can be selected while taking into account the competition between the expansion temperature of the thermally expandable capsule and the curing temperature and softening temperature of the resin.

[0045] (Topcoat)

[0046] The abrasive article of the present invention can be configured such that a top coating is provided on the side of the abrasive material layer opposite to the side that contacts the substrate.

[0047] The top coating contains a second abrasive, a second adhesive, and a metal soap, and may contain defoamers, leveling agents, etc., as needed.

[0048] By applying a top coating, one can achieve effects such as enhanced abrasive material layer formed using the first adhesive, reduced deep abrasive scratches, and improved cutting force.

[0049] (Abrasive grains)

[0050] The abrasive grains used as the top coating (second abrasive grains) can be the same as those used in the abrasive material layer (first abrasive grains), or different types and / or different grit sizes can be used.

[0051] (Adhesive)

[0052] There are no particular limitations on the adhesive (second adhesive) used for the top coating layer, as long as it can bond the top coating layer to the aforementioned abrasive material layer. Furthermore, the adhesive (second adhesive) used for the top coating layer can include photocurable acrylic resins, photocurable epoxy resins, photocurable polyurethane resins, thermosetting epoxy resins, thermosetting phenolic resins, thermosetting polyurethane resins, ethylene vinyl acetate resins, polyethylene resins, polyvinyl chloride resins, polypropylene resins, acrylonitrile butadiene styrene copolymer resins, ethylene propylene rubber, hydroxypropyl methylcellulose, hydroxypropyl cellulose, ethyl cellulose, polyvinyl butyral, polyvinyl acetal, etc. The adhesive (second adhesive) used for the top coating layer can be the same as the adhesive (first adhesive) used for the abrasive material layer, or a different adhesive can be used.

[0053] (Metallic soap)

[0054] Examples of metallic soaps include zinc stearate, magnesium stearate, calcium stearate, lithium stearate, or mixtures thereof.

[0055] By blending with metallic soaps, the lubricating properties of the metallic soaps can reduce the likelihood of deep scratches.

[0056] In some grinding processes, where the use of grinding materials containing metal soap is prohibited, a top coating without metal soap can be applied.

[0057] On the inner side of the abrasive surface of the abrasive article (the side of the substrate opposite to the surface in contact with the abrasive material layer), a sponge or similar material can be adhered as a buffer layer. The thickness of the sponge is preferably 2mm to 20mm, and more preferably 3mm to 10mm.

[0058] In addition, an adhesive material layer, hook and loop fasteners, or other locking components can be provided on the inside of the grinding surface of the grinding object.

[0059] The abrasive articles of the present invention can be manufactured, for example, by the following methods.

[0060] Reference Figure 1First, a coating liquid for preparing an abrasive material layer containing abrasive particles 2, an adhesive binder 3, thermally expandable microcapsules (thermally expandable hollow spherical capsules) 4, and a solvent is prepared. The solvent is preferably a solvent compatible with the adhesive binder 3, or a volatile solvent capable of dissolving the adhesive binder 3. Examples of solvents include methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and water.

[0061] Next, the coating liquid for the abrasive material layer is applied to the substrate (polyester film) 1 using a doctor blade coater. The hollow spherical capsule 4 is then expanded by heating, while the solvent is removed / dried. At this point, if a thermosetting resin is used as the adhesive 3, curing polymerization can also be performed.

[0062] When using a photopolymerizable adhesive as adhesive 3, the adhesive is then polymerized by irradiation with ultraviolet light using a photoinitiator. Examples of photoinitiators include IGM Resin B.Omnirad651, Omnirad184, Omnirad907, Omnirad1173, Omnirad2959, Omnirad127, Omnirad369, Omnirad369E, Omnirad379EG, OmniradTPO, Omnirad819, OmniradMBF, Omnirad754, OmniradOXE01, OmniradOXE02, OmniradOXE03, and OmniradOXE04.

[0063] Furthermore, a top coating containing abrasive particles 5 and metallic soap 6 is applied. Defoamers, leveling agents, etc., may be added to the top coating as needed.

[0064] A coating liquid for preparing the topcoat is made using a solvent that can dissolve or disperse abrasive particles 5, metal soap 6, and adhesive 7. The coating liquid is applied to the surface of the abrasive material layer of the abrasive object using a two-point roller coater or similar device, and then the topcoat is prepared by hot air drying (when a thermosetting resin is used as adhesive 7) or ultraviolet irradiation (when a photopolymerizable adhesive is used as adhesive 7).

[0065] Adhesive (or bonding agent) 8 can be applied to the inside of the grinding surface of the grinding object, sponge 9 can be attached, and then adhesive (or double-sided tape) 10 applied to the appropriate release paper 12 can be attached.

[0066] Alternatively, you can refer to Figure 2Apply adhesive (or bonding agent) 8 to the inside of the grinding surface of the grinding article, attach sponge 9, apply adhesive (or bonding agent) 8 to the sponge that becomes the inside of the grinding surface of the grinding article, and then attach hook and loop fastener 11.

[0067] Finally, the material is cut into any shape using laser processing or hydraulic pressure cutting tools, thus completing the polished item of the desired size / shape.

[0068] Example

[0069] The following examples illustrate embodiments for a better understanding of the invention and its advantages, but the invention is not limited to these embodiments.

[0070] (Example 1)

[0071] First, prepare a polyester film (CRISPER K2312 manufactured by Toyobo Co., Ltd.) as the substrate.

[0072] Next, in order to prepare a coating liquid for applying an abrasive material layer to a substrate, the raw materials are mixed and stirred with the following composition.

[0073] [Table 1]

[0074]

[0075] The coating liquid for the prepared abrasive material layer was applied using a doctor blade coater at a rate of 250 g / m². 2 The coating is applied to the substrate to a certain thickness. The coating solution is heated at 160°C for 5 minutes, allowing the solvent to evaporate while the thermally expandable microcapsules expand. Next, the coating solution is irradiated with ultraviolet light using a HERAUS D bulb at an output intensity of 240 W / cm, 100% output, and a speed of 10 m / min. This causes the adhesive to photopolymerize, thereby curing the coating solution and forming an abrasive material layer.

[0076] Next, in order to prepare a coating liquid for applying to the top layer of abrasive material, the raw materials are mixed and stirred with the following composition.

[0077] [Table 2]

[0078]

[0079] The topcoat coating liquid was applied using a 2-point roller coater at a rate of 50 g / m². 2 The coating solution is applied to the abrasive material layer with a thickness of [amount missing]. The coating solution is heated at 100°C for 2 minutes to evaporate the solvent, thereby forming the top coating layer.

[0080] Furthermore, double-sided tape (Nitto Denko Corporation No. 5000NS) is adhered as an adhesive layer to the side of the substrate opposite to the side where the abrasive material layer is formed, and laser processing is performed on it to produce a 32φ sheet-shaped abrasive article.

[0081] (Example 2)

[0082] The composition of the raw materials for the coating liquid used to make the abrasive material layer is as described below (the amount of thermally expandable microcapsules is set to a small amount), and the sheet-shaped abrasive articles are made in the same manner as in Example 1.

[0083] [Table 3]

[0084]

[0085] (Comparative Example 1)

[0086] The composition of the raw materials for the coating liquid used to make the abrasive material layer is as described below (the amount of thermally expandable microcapsules is set to a very small amount), and the sheet-shaped abrasive articles are made in the same manner as in Example 1.

[0087] [Table 4]

[0088]

[0089] (Example 3)

[0090] The composition of the raw materials for the coating liquid used to make the abrasive material layer is as described below, except that the sheet-shaped abrasive article is made in the same manner as in Example 1.

[0091] [Table 5]

[0092]

[0093] (Evaluation of abrasive items 1)

[0094] The performance of the abrasive articles prepared in Examples 1, 2, 3 and Comparative Example 1 was evaluated as follows.

[0095] That is, abrasive scratches were created on the surface of ECO ROCK Anti-Scratch Clear TR automotive paint manufactured by Rock Paint Co., Ltd. using a Tolecut K-2000 abrasive film manufactured by KOAAX CORPORATION. Abrasive articles prepared in Examples 1, 2, 3, and Comparative Example 1 were respectively attached to a KOAAX CORPORATION pneumatic blasting machine KT-501. Under conditions of air pressure 0.5 MPa and air flow control valve 2.5, the surface with abrasive scratches created using a handheld pneumatic tool was treated with the pressure applied to the cutting material, and the area where the abrasive scratches could be eliminated was measured.

[0096] For reference, the same evaluation was performed using 3M Japan Limited 32φ abrasive material (equivalent to Trizact 466AA5#3000, equivalent to Trizact 466LA A3#4000). (Refer to Example 1, Reference Example 2)

[0097] The results are summarized in the table below.

[0098] [Table 6]

[0099]

[0100] The evaluation results show that, according to the present invention, compared with the comparative example or the reference example, wide-area grinding scratches can be eliminated.

[0101] (Example 4)

[0102] The top coating was prepared in the same manner as in Example 1. Next, a 5mm thick sponge (Marulinzu PLS-30 manufactured by Marulinzu Co., Ltd.) was bonded to the inside of the abrasive surface of the abrasive article (the side of the substrate opposite to the side in contact with the abrasive material layer). Then, hook and loop fasteners were attached to the sponge. The sponge was then cut using a hydraulic pressure cutting tool to produce a 75φ sheet-shaped abrasive article.

[0103] (Example 5)

[0104] The top coating was prepared in the same manner as in Example 2. Next, a 5mm thick sponge (Marulinzu PLS-30 manufactured by Marulinzu Co., Ltd.) was bonded to the inside of the abrasive surface of the abrasive article (the side of the substrate opposite to the side in contact with the abrasive material layer). Then, hook and loop fasteners were attached to the sponge. The sponge was then cut using a hydraulic pressure cutting tool to produce a 75φ sheet-shaped abrasive article.

[0105] (Example 6)

[0106] The raw materials and composition of the coating liquid used to make the abrasive material layer are described below. Furthermore, the coating liquid for the top coating layer also uses the same abrasive particles (Fujimi Incorporated GC (Green Silicon Carbide Abrasive Material) #6000) as the raw materials used in the coating liquid for the abrasive material layer. Otherwise, the abrasive articles are made in the same manner as in Example 4.

[0107] [Table 7]

[0108]

[0109] (Example 7)

[0110] The raw materials and composition of the coating liquid used to make the abrasive material layer are described below. Furthermore, the coating liquid for the top coating layer also uses the same abrasive particles (Fujimi Incorporated GC (Green Silicon Carbide Abrasive Material) #8000) as the raw materials used in the coating liquid for the abrasive material layer. Otherwise, the abrasive articles are made in the same manner as in Example 4.

[0111] [Table 8]

[0112]

[0113] (Evaluation of abrasive items 2)

[0114] For the abrasive articles produced in Examples 4 and 5, their performance was evaluated using the same method as in Evaluation 1, except that 3M Japan Limited 28353 was used as a pneumatic blasting machine.

[0115] For reference, the same evaluation was conducted using 75φ foamed abrasive material (Trizact Finishing Disc #3000) manufactured by 3M Japan Limited. (See Example 3)

[0116] The results are summarized in the table below.

[0117] [Table 9]

[0118]

[0119] The evaluation results show that, according to the present invention, wide-area grinding scratches can be eliminated compared with the reference example.

[0120] (Evaluation of abrasive items 3)

[0121] For the abrasive article produced in Example 6, its performance was evaluated using the same method as Evaluation 2, except that abrasive scratches were made using the abrasive article produced in Example 4 (#3000).

[0122] For reference, the same evaluation was conducted using 75φ foamed abrasive material (Trizact Finishing Disc #5000) manufactured by 3M Japan Limited. (See Example 4)

[0123] The results are summarized in the table below.

[0124] [Table 10]

[0125]

[0126] The evaluation results show that, according to the present invention, wide-area grinding scratches can be eliminated compared with the reference example.

[0127] (Evaluation of abrasive items 4)

[0128] For the abrasive article produced in Example 7, its performance was evaluated using the same method as Evaluation 2, except that abrasive scratches were made using the abrasive article produced in Example 5 (#4000).

[0129] For reference, the same evaluation was conducted using 75φ foamed abrasive material (Trizact Finishing Disc #8000) manufactured by 3M Japan Limited. (See Example 5)

[0130] The results are summarized in the table below.

[0131] [Table 11]

[0132]

[0133] The evaluation results show that, according to the present invention, wide-area grinding scratches can be eliminated compared with the reference example.

[0134] Explanation of reference numerals in the attached figures

[0135] 1. Substrate

[0136] 2 Abrasive particles

[0137] 3. Adhesive

[0138] 4. Thermally Expandable Microcapsules

[0139] 5. Abrasive particles (for top coating)

[0140] 6. Metallic soap

[0141] 7. Adhesive for topcoat

[0142] 8. Adhesives (or bonding agents)

[0143] 9. Sponge

[0144] 10. Adhesive (or double-sided tape)

[0145] 11 Hook and loop fasteners

[0146] 12. Release paper.

Claims

1. A grinding article, characterized in that, It is a sheet-shaped abrasive article having a substrate and an abrasive material layer disposed on one side of the substrate. The abrasive material layer contains closed-cell air bubbles, a first abrasive grain, and a first adhesive. The inner diameter of the closed-cell bubble is 30μm~200μm. The average particle size of the first abrasive grain is less than one-third of the inner diameter of the closed-cell bubble. The first adhesive bondes the abrasive material layer to the substrate. Using the overall volume of the abrasive material layer as a benchmark, the closed-cell air bubbles account for 70% to 85% of the volume, the first abrasive grains account for 5% to 13% of the volume, and the first adhesive binder accounts for the remainder.

2. The grinding article according to claim 1, characterized in that, It also includes a top coating layer disposed on the surface of the abrasive material layer opposite to the surface that contacts the substrate. The top coating contains a second abrasive grain, a second adhesive, and a metal soap. The second adhesive bondes the top coating layer to the abrasive material layer.

3. The grinding article according to claim 1, characterized in that, The closed-cell bubble body is derived from thermally expandable microcapsules.

4. The grinding article according to claim 1, characterized in that, The first adhesive is a light-curing resin.

5. The grinding article according to claim 1, characterized in that, It also includes a buffer material layer disposed on the side of the substrate opposite to the side that contacts the abrasive material layer.

6. The grinding article according to claim 5, characterized in that, The cushioning material layer is a sponge.

7. The grinding article according to claim 1 or 2, characterized in that, It also has an adhesive layer on the side of the substrate opposite to the side that contacts the abrasive material layer.

8. The grinding article according to claim 1 or 2, characterized in that, It also has an engaging member layer on the side of the substrate opposite to the side that contacts the abrasive material layer.

9. The grinding article according to claim 5, characterized in that, It also has an adhesive layer or bonding agent layer on the side of the substrate opposite to the side that contacts the abrasive material layer.

10. The grinding article according to claim 5, characterized in that, It also has an engaging member layer on the side of the substrate opposite to the side that contacts the abrasive material layer.

11. The grinding article according to claim 5, characterized in that, It also has an adhesive layer or bonding agent layer on the side of the cushioning material layer opposite to the side that contacts the substrate.

12. The grinding article according to claim 5, characterized in that, It also has an engaging member layer on the side of the buffer material layer opposite to the side that contacts the substrate.

13. The grinding article according to claim 8, characterized in that, The engaging component layer is a hook and loop fastener.

14. The grinding article according to claim 10, characterized in that, The engaging component layer is a hook and loop fastener.

15. The grinding article according to claim 12, characterized in that, The engaging component layer is a hook and loop fastener.

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