Sheet-shaped abrasive article

Abstract

To provide a sheet-like abrasive article with a long service, which facilitates discharging chips of a material to be ground due to that an independent cellular body in an abrasive material layer included in the sheet-like abrasive article is provided with pores for discharging chips, and secures a space between the surface of the abrasive material layer and a material to be ground, and in which the abrasive material layer has self dressing properties due to that the independent cellular body of an abrasive material layer front layer part is collapsed by friction generated in polishing work, and new abrasive particles act on the material to be ground.SOLUTION: A sheet-like abrasive article comprises a substrate, and an abrasive material layer disposed on the one surface of the substrate. The abrasive article is such that: the abrasive material layer includes an independent cellular body, first abrasive particles, and a first adhesive bonding agent; an inner diameter of the independent cellular body is 30 μm-200 μm; an average particle diameter of the first abrasive particles is one-third or less of the inner diameter of the independent cellular body; the first adhesive bonding agent is for adhering the abrasive material layer to the substrate; and the independent cellular body occupies 70 vol.%-85 vol.%, the first abrasive particles occupy 5 vol.%-13 vol.%, and the first adhesive bonding agent occupies the remainder on the basis of the volume of the whole abrasive material layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sheet-like polishing article. In particular, the present invention relates to a sheet-like polishing article that can be suitably used for polishing a coating film to a mirror finish or a roughness just before becoming a mirror finish. The sheet-like polishing article according to the present invention is not limited to industrial grinding and polishing processes, and can also be effectively used in cleaning fields such as the surfaces of metals and IH heaters, the removal of scale from toilet ceramics, and the surfaces of glass.

Background Art

[0002] To finish the surface of an article to a mirror finish or a roughness just before becoming a mirror finish, a lapping film (abrasive), which is usually a precision polishing product, is normally used. However, in the case of polishing a coating film to this state, sufficient polishing power cannot be obtained with a lapping film. For this reason, lapping films are hardly used in the market for mirror finishing coating films. In the market for polishing a coating film to a mirror finish, abrasive materials (trade name: Tri-Zact) manufactured by 3M are widely used. The Tri-Zact abrasive material is said to be an abrasive material that applies a technique called "microreplication". That is, the Tri-Zact abrasive material is characterized by a regular microreplication structure, and it is said that it can achieve a stable finish and a stable polishing rate while preventing distortion due to heat. In addition, since the three-dimensional structure collapses and new abrasive grains come out, a uniform finish lasts for a long time, preventing rework. Furthermore, since polishing debris falls into the gaps of the three-dimensional surface structure, it is difficult to clog, and the polishing performance continues. However, in practice, it is extremely difficult to use up all the molded abrasive materials, which are pyramid structures of the Tri-Zact abrasive material, until they are completely worn out. For this reason, a product with a longer lifespan than Tri-Zact is desired.

[0003] Patent Document 1 discloses an abrasive material containing a cured product of a thermosetting resin powder and a porous body having a plurality of bubbles derived from thermally expandable microspheres, and abrasive grains dispersed in the porous body.

Prior Art Documents

Patent Document

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the present invention, an abrasive layer provided in a sheet-like abrasive article includes a closed-cell foam having a predetermined inner diameter and abrasive grains having an average particle size in a predetermined relationship with the inner diameter of the closed-cell foam. By setting the volume ratio of the closed-cell foam and the abrasive grains in the entire abrasive layer within a predetermined range, the closed-cell foam in the abrasive layer provided in the sheet-like abrasive article not only provides pores for chip discharge in the abrasive layer, but also secures a space between the surface of the abrasive layer (the surface of the top coat when a thin top coat is provided on the abrasive layer) and the work material, thereby facilitating the discharge of chips of the work material. The present invention also provides a long-life sheet-like abrasive article in which the abrasive grains of the abrasive layer containing the closed-cell foam are present on the wall surface of the closed-cell foam, so that the closed-cell foam in the surface layer portion of the abrasive layer collapses due to friction generated during the polishing operation, and new abrasive grains act on the work material, thereby enabling the abrasive layer to have self-dressing properties.

Means for Solving the Problems

[0006] That is, the present invention is a sheet-like abrasive article including a base material and an abrasive layer provided on one surface of the base material, wherein the abrasive layer includes a closed-cell foam, first abrasive grains, and a first adhesive binder. The inner diameter of the closed-cell foam is 30 μm to 200 μm, the average particle size of the first abrasive grains is 1 / 3 or less of the inner diameter of the closed-cell foam, the first adhesive binder adheres the abrasive layer to the base material, and based on the volume of the entire abrasive layer, the closed-cell foam is 70% to 85% by volume, the first abrasive grains are 5% to 13% by volume, and the balance is occupied by the first adhesive binder. The polishing article of the present invention further includes a top coat provided on a surface of the abrasive layer opposite to the surface in contact with the base material, and the top coat includes a second abrasive grain, a second adhesive binder, and a metal soap, and the second adhesive binder can be one that adheres the top coat to the abrasive layer. In the polishing article of the present invention, it is preferable that the closed-cell foam is derived from thermally expandable microcapsules. Also, in the polishing article of the present invention, it is preferable that the first adhesive binder is a photocurable resin.

[0007] The polishing article of the present invention can further include a buffer layer provided on a surface of the base material opposite to the surface in contact with the abrasive layer. In this case, it is preferable that the buffer layer is a sponge. The polishing article of the present invention can also further include an adhesive layer provided on a surface of the base material opposite to the surface in contact with the abrasive layer (the back side of the polishing action surface of the polishing article). Also, an adhesive layer can be further provided on the back side of the polishing action surface of the polishing article provided with the buffer layer. The polishing article of the present invention can further include an engaging member layer provided on a surface of the base material opposite to the surface in contact with the abrasive layer. Also, an engaging member layer can be further provided on the back side of the polishing action surface of the polishing article provided with the buffer layer. In this case, it is preferable that the engaging member layer is a hook-and-loop fastener.

Advantages of the Invention

[0008] According to the present invention, the closed-cell foam in the abrasive layer provides pores in the abrasive layer and secures a space between the surface of the abrasive layer and the work material to be machined, resulting in excellent chip discharge performance. Also, due to the large amount of closed-cell foam present in the abrasive layer, a sheet-shaped polishing article having self-dressing performance can be obtained. The sheet-shaped polishing article according to the present invention has efficient polishing workability and a large polishing area per unit abrasive surface area.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present invention will be described below.

[0011] (Base material) The base material used for the sheet-like polishing article of the present invention can be a polyester film, or latex-impregnated paper, latex barrier base paper, combinations thereof, and those obtained by surface treatment or the like. For example, when using a polyester film base material as the base material, those with improved adhesiveness by being subjected to an easy adhesion treatment can be preferably used. The thickness of the base material may be 25 to 500 μm, preferably 50 to 220 μm.

[0012] (Abrasive layer) The abrasive layer provided in the sheet-like polishing article of the present invention includes a closed-cell foam, a first abrasive grain, and a first adhesive binder. From the viewpoint that the polishing article of the present invention is sheet-like, the thickness of the abrasive layer formed on the base material is desirably 400 μm or less.

[0013] (Closed-cell foam) As the closed-cell structure, hollow balloons can be used, specifically, phenolic hollow balloons, glass hollow balloons, acrylonitrile thermally expandable hollow balloons, etc. Among them, acrylonitrile thermally expandable balloons (thermally expandable microcapsules) are easy to handle because the balloons before expansion have relatively high strength when preparing the coating liquid for the abrasive layer in the process of manufacturing the abrasive layer, and the specific gravity of the balloons before expansion does not differ significantly from that of other raw materials of the abrasive layer. Therefore, the raw materials can be uniformly mixed and stirred to prepare the coating liquid for the abrasive layer, and it is particularly suitable in that it is easy to make the distribution of the closed-cell structure in the abrasive layer uniform.

[0014] The inner diameter of the closed-cell structure (this means the pore size in the abrasive layer. When the closed-cell structure is derived from a thermally expandable balloon, it corresponds to the inner diameter of the expanded thermally expandable balloon) is 30 μm to 200 μm. If the inner diameter of the closed-cell structure is 30 μm or less, it is considered difficult to form a sufficient space for discharging the chips generated during polishing. On the other hand, from the viewpoint of stabilizing the strength of the abrasive layer, it is considered desirable that the inner diameter of the closed-cell structure is not more than half of the thickness of the abrasive layer. As described above, since it is considered desirable that the thickness of the abrasive layer is 400 μm or less, the upper limit of the inner diameter of the closed-cell structure is 200 μm. The inner diameter of the closed-cell structure is preferably 50 μm to 150 μm. The inner diameter of the closed-cell structure can be measured by using a digital microscope (for example, KEYENCE digital microscope VHX-6000).

[0015] The inner diameter of the closed-cell structure is at least three times the average particle diameter of the abrasive grains used (in other words, the average particle diameter of the abrasive grains is not more than one-third of the inner diameter of the closed-cell structure). The reason for setting the average particle diameter of the abrasive grains to not more than one-third of the inner diameter of the closed-cell structure is that when the abrasive layer coating liquid is applied and the thermally expandable balloon is expanded, if the average particle diameter of the abrasive grains exceeds one-third of the inner diameter of the closed-cell structure, the presence of the abrasive grains around the thermally expandable balloon is likely to be biased. The average particle size of the abrasive grains can be measured, for example, by the electric resistance test method (see JIS R 6001-2:2017).

[0016] (Abrasive grains) As described above, the average particle size of the abrasive grains (the first abrasive grains) in the abrasive layer is 1 / 3 or less of the inner diameter of the closed-cell foam. As the abrasive grains in the abrasive layer, those having an average particle size of 0.3 μm to 46 μm can be preferably used. The average particle size of the abrasive grains can be determined, for example, using the electric resistance method as the particle size measurement method. As the abrasive grains in the abrasive layer, those composed of diamond, cubic boron nitride, alumina, silicon carbide, cerium oxide, or silicon dioxide can be used alone or in combination.

[0017] (Adhesive binder) The adhesive binder (the first adhesive binder) of the abrasive layer is not particularly limited as long as it can adhere the abrasive layer to the base material. Examples thereof include photocurable acrylic resins, photocurable epoxy resins, photocurable urethane resins, thermosetting epoxy resins, thermosetting phenolic resins, thermosetting urethane resins, ethylene vinyl acetate resins, polyethylene resins, polyvinyl chloride resins, polypropylene resins, acrylonitrile butadiene styrene copolymer synthetic resins, and ethylene propylene rubber. When, for example, thermally expandable microcapsules (such as acrylonitrile thermally expandable balloons) are used as the closed-cell foam, a suitable type of adhesive binder to be used in combination therewith is a photocurable adhesive. This is because after the expansion of the thermally expandable balloon is completed, it is possible to cure the adhesive binder by photocuring at an arbitrary timing, so that it becomes easy to realize an abrasive layer containing the closed-cell foam, abrasive grains, and adhesive binder in a (volume) ratio as designed in advance. Of course, in this case, when it is necessary to use a thermoplastic resin or a thermosetting resin as the adhesive binder, the thermally expandable balloon and the adhesive binder may be selected while paying attention to the competition between the expansion temperature of the thermally expandable balloon and the resin curing temperature or the resin softening temperature.

[0018] (Top coat) The polishing article of the present invention can be provided with a top coat on the surface of the abrasive layer opposite to the surface in contact with the substrate. The top coat contains a second abrasive grain, a second binder, and a metal soap, and may contain an antifoaming agent, a leveling agent, etc. as necessary. By providing the top coat, effects such as reinforcement of the abrasive layer formed by the first binder, reduction of the occurrence of deep polishing scratches, and improvement of cutting force can be obtained.

[0019] (Abrasive grain) As the abrasive grain (second abrasive grain) of the top coat, the same abrasive grain as the abrasive grain (first abrasive grain) of the abrasive layer may be used, or different types and / or different particle sizes may be used.

[0020] (Binder) The binder (second binder) of the top coat is not particularly limited as long as it can adhere the top coat to the abrasive layer. Further, as the binder (second binder) of the top coat, a photocurable acrylic resin, a photocurable epoxy resin, a photocurable urethane resin, a thermosetting epoxy resin, a thermosetting phenol resin, a thermosetting urethane resin, an ethylene vinyl acetate resin, a polyethylene resin, a polyvinyl chloride resin, a polypropylene resin, an acrylonitrile butadiene styrene copolymer synthetic resin, an ethylene propylene rubber, hydroxypropyl methyl cellulose, hydroxypropyl cellulose, ethyl cellulose, polyvinyl butyral, polyvinyl acetal, etc. can be used. As the binder (second binder) of the top coat, the same binder as the binder (first binder) of the abrasive layer may be used, or different binders may be used.

[0021] (Metal soap) Examples of the metal soap include zinc stearate, magnesium stearate, calcium stearate, lithium stearate, or a mixture thereof. By incorporating metallic soap, the probability of deep scratch marks due to the lubricity of the metallic soap can be reduced. In the case where the use of a polishing article containing metallic soap is prohibited in some polishing processes, a top coat without metallic soap can also be applied.

[0022] A sponge such as a sponge cushion can be attached to the back side of the polishing action surface of the polishing article (the surface of the base material opposite to the surface in contact with the abrasive layer) as a buffer layer. The thickness of the sponge is preferably 2 mm to 20 mm, more preferably 3 mm to 10 mm. An engaging member layer such as an adhesive layer or a hook-and-loop fastener can also be provided on the back side of the polishing action surface of the polishing article.

[0023] The polishing article of the present invention can be manufactured, for example, by the following method. Referring to FIG. 1, first, a coating liquid for an abrasive layer containing abrasive grains 2, an adhesive binder 3, thermally expandable microcapsules (thermally expandable hollow balloons) 4, and a solvent is prepared. The solvent is preferably a substance compatible with the adhesive binder 3 or a volatile solvent capable of dissolving the adhesive binder 3. Examples of the solvent include methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, water, and the like. Next, the coating liquid for the abrasive layer is applied onto a base material (polyester film) 1 with a knife coater, the thermally expandable hollow balloons 4 are expanded by heating, and at the same time, the solvent is removed and dried. When a thermosetting resin is used as the adhesive binder 3, curing polymerization may be performed. When a photo-curable adhesive is used as the binder 3, the adhesive is then polymerized by irradiating ultraviolet rays using a photoinitiator. Examples of photoinitiators include IGM Resin B.V Omnirad651, Omnirad184, Omnirad907, Omnirad1173, Omnirad2959, Omnirad127, Omnirad369, Omnirad369E, Omnirad379EG, OmniradTPO, Omnirad819, OmniradMBF, Omnirad754, OmniradOXE01, OmniradOXE02, OmniradOXE03, OmniradOXE04, etc.

[0024] Furthermore, a top coat containing abrasive grains 5 and metal soap 6 is provided. Defoamers, leveling agents, etc. can be added to the top coat as necessary. A coating solution for the top coat is prepared using a solvent capable of dissolving or dispersing the abrasive grains 5, metal soap 6, and binder 7. The coating solution is applied to the surface of the abrasive layer of the polishing article using a two-roll coater or the like, and then heat drying (when a thermosetting resin is used as the binder 7) or ultraviolet irradiation (when a photo-curable adhesive is used as the binder 7) is performed to produce the top coat.

[0025] An adhesive (or binder) 8 is applied to the back side of the polishing surface of the polishing article, a sponge 9 is attached, and an adhesive (or double-sided tape) 10 applied to a suitable release paper 12 can be further attached. Also, referring to FIG. 2, an adhesive (or binder) 8 is applied to the back side of the polishing surface of the polishing article, a sponge 9 is attached, an adhesive (or binder) 8 is applied to the sponge on the back side of the polishing surface of the polishing article, and a hook-and-loop fastener 11 can be further attached. Finally, a polishing article of a desired size and shape is completed by laser processing or cutting into an arbitrary shape using a hydraulic press tool.

Example

[0026] Examples for better understanding of the present invention and its advantages are illustrated below, but the present invention is not limited to the examples.

[0027] (Example 1) First, as a base material, a polyester film (Crisper K2312 manufactured by Toyobo Co., Ltd.) was prepared. Next, in order to prepare a coating liquid for the abrasive layer to be applied to the base material, raw materials were mixed and stirred with the following composition.

[0028] [Table 1]

[0029] The prepared coating liquid for the abrasive layer was applied onto the base material at a thickness of 250 g / m 2 using a knife coater. The coating liquid was heated at 160°C for 5 minutes to volatilize the solvent and expand the thermally expandable microcapsules. Next, using a Heraeus D valve, ultraviolet rays were irradiated onto the coating liquid under the conditions of an output intensity of 240 W / cm, an output of 100%, and a speed of 10 m / min to photopolymerize the adhesive binder, thereby curing the coating liquid to form an abrasive layer.

[0030] Next, in order to prepare a coating liquid for the top coat to be applied to the abrasive layer, raw materials were mixed and stirred with the following composition.

[0031] [Table 2]

[0032] The prepared coating liquid for the top coat was applied onto the abrasive layer at a thickness of 50 g / m 2 using a two-roll coater. The coating liquid was heated at 100°C for 2 minutes to volatilize the solvent and form a top coat.

[0033] Furthermore, a double-sided tape (No. 5000NS manufactured by Nitto Denko Corporation) was attached as an adhesive layer to the surface of the base material opposite to the surface on which the abrasive layer was formed, and this was laser-processed to produce a sheet-shaped abrasive article with a diameter of 32φ.

[0034] (Example 2) A sheet-shaped abrasive article was produced in the same manner as in Example 1, except that the composition of the raw materials for preparing the coating liquid for the abrasive layer was as follows (the blending amount of the thermally expandable microcapsules was made small).

[0035]

Table 3

[0036] (Comparative Example 1) A sheet-shaped abrasive article was produced in the same manner as in Example 1, except that the composition of the raw materials for preparing the coating liquid for the abrasive layer was as follows (the blending amount of the thermally expandable microcapsules was made much smaller).

[0037]

Table 4

[0038] (Example 3) A sheet-shaped abrasive article was produced in the same manner as in Example 1, except that the composition of the raw materials for preparing the coating liquid for the abrasive layer was as follows.

[0039]

Table 5

[0040] (Evaluation 1 of Abrasive Articles) Regarding the abrasive articles produced in Examples 1, 2, 3 and Comparative Example 1, their performance was evaluated as follows. That is, abrasion marks were made on the surface of the vehicle paint Eco Lock Anti-Scratch Clear TR manufactured by Rock Paint Co., Ltd. using the abrasive film Track Cut K-2000 manufactured by Kobax Co., Ltd. The polished articles prepared in Examples 1, 2, 3 and Comparative Example 1 were respectively attached to the air sander KT-501 manufactured by Kobax Co., Ltd., and under the conditions of an air pressure of 0.5 MPa and an air flow rate adjustment valve of 2.5, they were pressed against the workpiece to be cut at the normal pressure when using a hand-held air tool, and the surface with abrasion marks was treated using grinding water, and the area where the abrasion marks could be eliminated was measured. For reference, the same evaluation was performed using abrasives with a diameter of 32φ manufactured by 3M Japan Co., Ltd. (equivalent to Tri-Zact 466A A5 #3000 and equivalent to Tri-Zact 466LA A3 #4000). (Reference Example 1, Reference Example 2) The results are summarized in the following table.

[0041]

Table 6

[0042] From the evaluation results, it is understood that according to the present invention, abrasion marks over a wider area can be eliminated compared to those of the comparative example or the reference example. (Example 4) Similar to Example 1, the top coat was prepared. Next, adhesive processing was performed on the back side of the polishing working surface of the polished article (the surface of the base material opposite to the surface in contact with the abrasive layer), and a sponge with a thickness of 5 mm (PLS-30 manufactured by Maru Suzuri Co., Ltd.) was attached. Further, a hook-and-loop fastener was attached to the sponge. This was cut out using a hydraulic press blade to produce a 75φ sheet-shaped polished article. (Example 5) Similar to Example 2, the top coat was prepared. Next, adhesive processing was performed on the back side of the polishing working surface of the polished article (the surface of the base material opposite to the surface in contact with the abrasive layer), and a sponge with a thickness of 5 mm (PLS-30 manufactured by Maru Suzuri Co., Ltd.) was attached. Further, a hook-and-loop fastener was attached to the sponge. This was cut out using a hydraulic press blade to produce a 75φ sheet-shaped polished article.

[0043] (Example 6) The raw materials and their compositions for preparing the coating liquid for the abrasive layer were as follows. Furthermore, except that the same abrasive grains (GC (green silicon carbide abrasive) #6000 manufactured by Fujimi Incorporated) as those used in the coating liquid for the abrasive layer were also used in the coating liquid for the top coat, a polished article was produced in the same manner as in Example 4.

[0044] [Table 7]

[0045] (Example 7) The raw materials and their compositions for preparing the coating liquid for the abrasive layer were as follows. Furthermore, except that the same abrasive grains (GC (green silicon carbide abrasive) #8000 manufactured by Fujimi Incorporated) as those used in the coating liquid for the abrasive layer were also used in the coating liquid for the top coat, a polished article was produced in the same manner as in Example 4.

[0046] [Table 8]

[0047] (Evaluation 2 of the Polished Article) For the polished articles produced in Examples 4 and 5, their performance was evaluated in the same manner as in Evaluation 1, except that 28353 manufactured by 3M Japan Co., Ltd. was used as the air sander. For reference, the same evaluation was performed using an abrasive material with a foam (Trizact Finishing Disc #3000) of 75φ manufactured by 3M Japan Co., Ltd. (Reference Example 3) The results are summarized in the following table. [Table 9]

[0048] From the evaluation results, it is understood that according to the present invention, polishing scratches with a wide area can be eliminated as compared with the reference example.

[0049] (Evaluation 3 of the Polished Article) Regarding the polishing article produced in Example 6, its performance was evaluated in the same manner as in Evaluation 2, except that polishing scratches were made on the polishing article produced in Example 4 (#3000). For reference, the same evaluation was performed using a 75φ abrasive with a foam (Trizact Finishing Disc #5000) manufactured by 3M Japan Co., Ltd. (Reference Example 4). The results are summarized in the following table.

Table 10

[0050] From the evaluation results, it is understood that according to the present invention, polishing scratches over a wide area can be eliminated as compared with the reference example.

[0051] (Evaluation 4 of Polishing Article) Regarding the polishing article produced in Example 7, its performance was evaluated in the same manner as in Evaluation 2, except that polishing scratches were made on the polishing article produced in Example 5 (#4000). For reference, the same evaluation was performed using a 75φ abrasive with a foam (Trizact Finishing Disc #8000) manufactured by 3M Japan Co., Ltd. (Reference Example 5). The results are summarized in the following table.

Table 11

[0052] From the evaluation results, it is understood that according to the present invention, polishing scratches over a wide area can be eliminated as compared with the reference example.

Explanation of Reference Signs

[0053] 1 Substrate 2 Abrasive Grains 3 Adhesive Bond 4 Thermally Expandable Microcapsules 5 Abrasive Grains (for Top Coat) 6 Metal Soap 7 Adhesive Bond (for Top Coat) 8 Adhesive (or bonding agent) 9 Sponge 10 Adhesive (or double-sided tape) 11 Hook-and-loop fastener 12 Release paper

Claims

1. A sheet-like polishing article comprising a base material and an abrasive layer provided on one surface of the base material, wherein the abrasive layer contains closed-cell foams, first abrasive grains, and a first adhesive binder, the average inner diameter of the closed-cell foams is included in the range of 30 μm to 200 μm, the average particle diameter of the first abrasive grains is 1 / 3 or less of the average inner diameter of the closed-cell foams, the first adhesive binder adheres the abrasive layer to the base material, based on the volume of the entire abrasive layer, the closed-cell foams account for 70% to 85% by volume, the first abrasive grains account for 5% to 13% by volume, and the remainder is occupied by the first adhesive binder, A polishing article, characterized by the above.

2. Further comprising a top coat provided on the surface of the abrasive layer opposite to the surface in contact with the base material, wherein the top coat contains second abrasive grains, a second adhesive binder, and metal soap, the second adhesive binder adheres the top coat to the abrasive layer, The polishing article according to claim 1, characterized by the above.

3. The closed-cell foams are derived from thermally expandable microcapsules, The polishing article according to claim 1 or 2, characterized by the above.

4. The first adhesive binder is a photocurable resin, The polishing article according to claim 1 or 2, characterized by the above.

5. Further comprising a buffer layer provided on the surface of the base material opposite to the surface in contact with the abrasive layer, The polishing article according to claim 1 or 2, characterized by the above.

6. The buffer layer is a sponge, The polishing article according to claim 5, characterized by the above.

7. The polishing article further comprises an adhesive layer on the surface of the base material opposite to the surface in contact with the abrasive layer. The polishing article according to claim 1 or 2.

8. The polishing article further comprises an engaging member layer on the surface of the base material opposite to the surface in contact with the abrasive layer. The polishing article according to claim 1 or 2.

9. The engaging member layer is a hook-and-loop fastener, The polishing article according to claim 8, characterized by the above.

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