Abrasive material and method for manufacturing the same

Abstract

To provide abrasive material which has a small influence on workability by abrasive grains and can be expected to have a sufficient anchor effect without limiting the abrasive grains, and also to provide a method for manufacturing a grindstone including a method for manufacturing the abrasive material.SOLUTION: Abrasive material of the present invention includes abrasive grains and adhesive material adhered to a surface of the abrasive grains. The adhesive material forms mesh-like protrusions on the surface of the abrasive grains.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an abrasive material and a method for making the abrasive material. [Background technology]

[0002] In tools such as grinding wheels that contain abrasive grains and a bond that holds the abrasive grains, one of the factors that influences the processing performance is the strength with which the bond holds the abrasive grains, i.e., the abrasive grain retention force. In particular, when the abrasive grains are made of diamond, the abrasive grain retention force is low due to poor wetting between the bond and the abrasive grains.

[0003] To improve the abrasive grain retention, roughness is imparted to the surface of the abrasive grains. For example, Non-Patent Document 1 discloses a commercially available abrasive consisting of abrasive grains and a metal layer coated on the surface of the abrasive grains. Patent Document 1 also discloses an abrasive consisting of abrasive grains and a layer of oxide microparticles attached to the surface of the abrasive grains. In these abrasives, the metal layer and the oxide microparticle layer ensure roughness, which can increase the anchoring effect for the bond.

[0004] Also, as in Patent Document 2, it has been proposed to subject the surfaces of abrasive grains to a coupling treatment to form an abrasive material, and to use a coupling agent to prevent the abrasive grains from falling off the bond. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5458459 [Patent Document 2] Patent Publication No. 2021-84975 [Non-patent literature]

[0006] [Non-Patent Document 1] https: / / www.global-diamond.co.jp / product / diamond.html#a03 Summary of the Invention [Problem to be solved by the invention]

[0007] However, abrasives with metal layers or oxide microparticle layers have concerns that the anchoring effect is not necessarily sufficient because the metal layers or oxide microparticle layers that create the unevenness are rounded. Furthermore, these abrasives have concerns that the metal layers or oxide microparticle layers cover almost the entire surface of the abrasive grains, which significantly affects the workability of the abrasive grains. On the other hand, abrasives whose abrasive grain surfaces have been subjected to a coupling treatment cannot be expected to have an anchoring effect, raising concerns about the abrasive grain retention, and limiting the abrasive grains that can be reacted with the coupling agent.

[0008] The present invention has been made in consideration of the above-mentioned conventional practical applications, and aims to solve the problem of providing an abrasive material that has little effect on processability due to abrasive grains, is not limited to abrasive grains, and can be expected to have a sufficient anchoring effect. [Means for solving the problem]

[0009] The abrasive material of the present invention comprises abrasive grains and an adhesive material attached to the surfaces of the abrasive grains, The adhesive material is characterized in that it has a mesh-like projection formed on the surface thereof.

[0010] The abrasive material of the present invention has an adhesive material attached to the surface of the abrasive grains, and the adhesive material forms mesh-like convex portions on the surface of the abrasive grains, which can be expected to have a higher anchoring effect. In particular, because the convex portions of this abrasive material are mesh-like, three-dimensional convex portions are formed on the surface of the abrasive grains, and the anchoring effect improves the abrasive grain retention against loads from various directions. Furthermore, because the convex portions of this abrasive material only partially cover the abrasive grains with the mesh, the abrasive grains have almost no effect on the processability. This abrasive material can be used to produce grinding wheels such as vitrified-bond grinding wheels, resin-bond grinding wheels, and metal-bond grinding wheels. Because these grinding wheels have high abrasive grain retention, they can exhibit high processing performance. Tools using these grinding wheels can also be produced.

[0011] The method for producing an abrasive material of the present invention includes a first step of preparing abrasive grains and a sol in which elongated raw fiber fibers are dispersed in a liquid dispersion medium; a second step of mixing the abrasive grains and the sol to obtain a mixture; The method is characterized by comprising a third step of removing the liquid dispersion medium from the mixture to obtain an abrasive material comprising the abrasive grains and mesh-like protrusions formed by solidifying the raw fiber and adhering to the surfaces of the abrasive grains.

[0012] The abrasive manufacturing method of the present invention can manufacture the abrasive of the present invention. In particular, since the mixture is made by mixing abrasive grains and a sol in a liquid dispersion medium, the raw fiber easily becomes entangled with the abrasive grains. When the liquid dispersion medium is removed from this mixture, the raw fiber becomes a mesh-like convex portion, solidifies on the surface of the abrasive grains, and easily adheres to them. A grinding wheel can be manufactured using this abrasive manufacturing method. [Effects of the Invention]

[0013] The abrasive of the present invention has little effect on processability due to abrasive grains, and a sufficient anchoring effect can be expected without any restrictions on abrasive grains.Furthermore, the abrasive of the present invention can be produced by the method for producing the abrasive of the present invention. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a field emission scanning electron microscope photograph of the abrasive material of Test Example 8 at 5000 magnifications. [Figure 2] 1 is a field emission scanning electron microscope photograph of the abrasive material of Test Example 8 at 150,000 magnifications. [Figure 3] 10 is a graph showing the relationship between the amount of wear of the abrasive and the amount of processing of the wafer for the abrasive of Test Example 4 and the abrasive of the Comparative Example. DETAILED DESCRIPTION OF THE INVENTION

[0015] The material of the abrasive grains that make up the abrasive is not particularly limited, but examples include diamond, CBN, silicon carbide, alumina, zirconia, ceria, chromium oxide, iron oxide, silica, titania, etc., as well as mixtures thereof. In particular, superabrasive grains (diamond, CBN) are preferably used for processing difficult-to-process materials such as semiconductor wafers, which require stronger abrasive grain retention. In particular, when diamond, which has poor wettability with the bond, is used, the effect of the fiber is easily demonstrated.

[0016] The material of the adhesive constituting the abrasive is not particularly limited, but oxide ceramics, hydroxides, glass, cellulose, etc., and mixtures thereof are preferred. Because the adhesive forms a mesh-like convex portion on the surface of the abrasive grain, the adhesive is preferably composed of long fibers. The convex portions may be formed by crossing the fibers. The fibers may be oxide ceramics, hydroxides, glass, cellulose, etc., and mixtures thereof. The fibers before being used to form the abrasive are raw fiber. When a process of heat-treating the abrasive at 300°C or higher is required to obtain a vitrified-bonded grinding wheel, highly heat-resistant oxide ceramics or glass are preferably used as raw fiber. Furthermore, raw fiber made of oxide ceramics, hydroxides, and glass has good wettability with the vitrified bond, which is an oxide, and is therefore suitable for use. Raw fiber made of cellulose has low heat resistance, but is suitable for use when high-temperature treatment is not required to obtain a resin-bonded or metal-bonded grinding wheel.

[0017] The type of oxide ceramic is not particularly limited, but examples thereof include alumina, silica, titania, zirconia, yttria, niobium oxide, hydrates thereof, and composite oxides and mixtures containing metal (semi-metal) elements contained therein. Examples of hydroxides include boehmite.

[0018] The glass is not particularly limited, but examples include systems containing silica, alumina, titania, zirconia, and boron oxide as main components. The total content of these components is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0019] It is preferable that the fibers are bonded at at least some of the intersections of the fibers in the abrasive material. In this case, the mesh-like protrusions on the surface of the abrasive grains are firmly held in place. The bonding can be by sintering if the fibers are made of oxide ceramics or hydroxide, by welding if the fibers are made of glass, or by adhesive bonding if the fibers are made of cellulose.

[0020] The diameter of the convex portions of the abrasive, which is the width in the direction perpendicular to the longitudinal direction, is preferably 1 / 10 or less of the particle diameter of the abrasive grains, more preferably 1 / 100 or less, even more preferably 1 / 200 or less, even more preferably 1 / 500 or less, and particularly preferably 1 / 1000 or less. At this time, a mesh-like convex portion is suitably formed on the surface of the abrasive grains. The diameter of the convex portions is the average value of the width in the direction perpendicular to the longitudinal direction of the fibers forming the convex portions measured at 200 random points in a microscope image of the abrasive. The particle diameter of the abrasive grains is the average value of the major and minor diameters obtained from an observation image of the abrasive grains.

[0021] The diameter of the convex portions of the abrasive is preferably 1 nm or more, more preferably 2 nm or more, and particularly preferably 3 nm or more. A thicker diameter fiber provides a stronger anchoring effect. The diameter of the convex portions is preferably 5 μm or less, more preferably 1 μm or less, even more preferably 0.1 μm or less, even more preferably 0.05 μm or less, preferably 0.02 μm or less, even more preferably 0.01 μm or less, and particularly preferably 0.005 μm or less. Since the fibers forming the convex portions are flexible, they fit and adhere to the shape of the abrasive grains. Furthermore, the fibers are entangled on the surface of the abrasive grains, forming the convex portions in an optimal manner. The diameter of the convex portions is the average value of the width of the fibers forming the convex portions in a direction perpendicular to the longitudinal direction of the fibers in a microscope image of the abrasive, measured at 200 random points.

[0022] The length of the convex portions of the abrasive material in the longitudinal direction is preferably 50 nm or more, more preferably 100 nm or more, even more preferably 200 nm or more, even more preferably 500 nm or more, and particularly preferably 1000 nm or more. Long fibers tend to entangle easily, effectively forming convex portions on the surface of the abrasive grain. The length of the fibers forming the convex portions is preferably 300 μm or less, more preferably 100 μm or less, even more preferably 10 μm or less, even more preferably 5 μm or less, and particularly preferably 3 μm or less. If the fibers are too long, they tend to fall off from the surface of the abrasive grain and are difficult to adhere to the abrasive grain as convex portions. The length of the convex portions is the average length of the fibers forming the convex portions in the longitudinal direction measured for 200 fibers in a microscopic image of the abrasive material. Note that because the fibers cross to form the mesh-like convex portions, both ends or one end of each fiber may be unclear, but even in this case, the lower limit of the convex portion length is clear.

[0023] The length / diameter aspect ratio of the convex portions of the abrasive is preferably 20 or more, more preferably 50 or more, even more preferably 100 or more, even more preferably 200 or more, and particularly preferably 300 or more. Fibers with a large aspect ratio tend to intertwine easily and favorably form convex portions on the surface of the abrasive grain. Note that because the fibers intersect to form a mesh-like convex portion, both ends or one end of each fiber may be unclear in a microscopic image of the abrasive. Even in this case, the lower limit of the length of the convex portions and the lower limit of the aspect ratio of the convex portions are clearly defined.

[0024] The convex part of the abrasive has an adhesion amount of 0.001 g / m per unit BET surface area of ​​abrasive grains. 2 More than 0.002 g / m is preferable. 2 More preferably, 0.005 g / m or more 2 More preferably, 0.01 g / m or more 2 The above is particularly preferable. In these cases, convex portions are suitably formed on the surface of the abrasive grain. On the other hand, the fiber forming the convex portions has an adhesion amount per unit BET surface area of ​​the abrasive grain of 0.4 g / m 2 Less than 0.2 g / m is preferred 2 Less than 0.1 g / m is more preferable. 2 More preferably, 0.06 g / m or less 2 The following are particularly preferable. In these cases, a decrease in abrasive grain retention force due to excessive fiber adhesion is suppressed. In addition, since the surface of the abrasive grains can be exposed to some extent, the influence of the protrusions on the workability of the abrasive grains can be suppressed.

[0025] When the abrasive grains are superabrasive grains, the fibers are preferably oxides or hydroxides of at least one of metals and semi-metals (e.g., Si), or mixtures thereof. The inventors have confirmed the effectiveness of the present invention using this abrasive material. In particular, test results show that the fibers are preferably at least one of alumina and boehmite.

[0026] The abrasive is not particularly limited in its application, but is preferably used for processing semiconductor wafers. Examples of semiconductor wafers include SiC, Si, GaN, Ga2O3, and diamond. Among these, it is preferably used for processing SiC and Si, especially SiC.

[0027] In the method for manufacturing an abrasive material, the third step preferably includes a sintering step in which the raw fiber fibers intersect on the surface of the abrasive grain. The top temperature of the firing temperature in the sintering step is not particularly limited, as it is adjusted appropriately depending on the material and size of the raw fiber. However, it is preferably 200°C or higher, more preferably 300°C or higher, even more preferably 400°C or higher, and particularly preferably 500°C or higher. In these cases, the raw fiber fibers are suitably sintered, and a strong mesh-like projection is formed on the surface of the abrasive grain. Furthermore, the top temperature is preferably 1200°C or lower, more preferably 1000°C or lower, even more preferably 800°C or lower, and particularly preferably 600°C or lower. In these cases, reduction of the mesh-like projection due to excessive sintering of the raw fiber can be suppressed.

[0028] The diameter and length of the raw fiber used in the manufacturing process and the protrusions on the abrasive will differ depending on the manufacturing method of the abrasive. This is because when heating is performed in the third step of the manufacturing process, the raw fiber will shrink depending on the material. The rate of shrinkage will vary depending on the material, temperature, etc.

[0029] The length of the raw fiber used in the manufacturing method is preferably less than the median diameter of the abrasive grains, more preferably 0.8 times or less, even more preferably 0.5 times or less, and particularly preferably 0.3 times or less. The length of the raw fiber is the average value of the longitudinal length of each fiber measured for 200 fibers in a microscopic image of the raw fiber. In these cases, the raw fiber adheres favorably to the surface of the abrasive grains, and the fibers also adhere favorably to the surface of the abrasive grains. Here, the median diameter of the abrasive grains is the median diameter based on the number of particles measured by laser diffraction.

[0030] The diameter of the raw fiber is 1 nm or more, more preferably 2 nm or more, or 3 nm or more. At this time, mesh-like convex portions of appropriate size are formed on the surface of the abrasive grain. Furthermore, the diameter of the raw fiber is 5 μm or less, more preferably 1 μm or less, 0.1 μm or less, 0.05 μm or less, 0.02 μm or less, or 0.01 μm or less. At this time, the raw fiber is flexible, so it fits and adheres to the shape of the abrasive grain. Furthermore, the raw fiber is entangled on the surface of the abrasive grain, forming a mesh-like convex portion in an appropriate manner. The diameter of the raw fiber is the average value of the width of each fiber in the direction perpendicular to the longitudinal direction at the center of the longitudinal direction in a microscopic image of the raw fiber, measured for 200 fibers.

[0031] Furthermore, the length of the raw fiber is preferably 50 nm or more, 100 nm or more, 200 nm or more, 500 nm or more, or 1000 nm or more. In this case, the raw fiber becomes entangled, thereby favorably forming a mesh-like convex portion on the surface of the abrasive grain. In addition, the length of the raw fiber is preferably 300 μm or less, 100 μm or less, 10 μm or less, 5 μm or less, or 3 μm or less. In this case, the raw fiber easily adheres to the surface of the abrasive grain. The length of the raw fiber is the average value of the longitudinal length of each fiber measured for 200 fibers in a microscopic image of the raw fiber.

[0032] The aspect ratio (length / diameter) of the raw material fibers is 20 or more, more preferably 50 or more, 100 or more, 200 or more, or 300 or more. In this case, the raw material fibers are entangled, which favorably forms a mesh-like convex portion on the surface of the abrasive grains, improving the abrasive grain retention force.

[0033] The amount of raw fiber attached per unit BET surface area of ​​the abrasive grain is adjusted by the content of raw fiber relative to the total weight of the abrasive grain and raw fiber. The content of raw fiber relative to the total weight of the abrasive grain and raw fiber is preferably 0.02% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more. In these cases, a mesh-like convex portion is formed on the surface of the abrasive grain at an appropriate ratio. On the other hand, the content of raw fiber is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass or less. In these cases, it is possible to prevent excessive raw fiber from adhering to the abrasive grain and reducing its abrasive grain retention. Furthermore, since the surface of the abrasive grain can be exposed to some extent, the influence of the fiber on the workability of the abrasive grain can be reduced. When alumina or boehmite is used as the raw fiber for alumina or boehmite fibers, the preferred dimensions and attachment amount of the fiber in the abrasive are the preferred dimensions and content of the raw fiber.

[0034] The abrasive material of the present invention may be produced by a method other than the method of the present invention. For example, a method may be used in which fibers are produced in a reaction system containing abrasive grains, and then materials other than the abrasive grains and fibers are removed. When using fibers made of oxide ceramics or glass fibers, a sol-gel method may be used as a method for producing the fibers. [Example]

[0035] In the first step, diamond A ("FRM40-60" manufactured by Global Diamond Co., Ltd.) and diamond B ("FRM4-6" manufactured by Global Diamond Co., Ltd.) were prepared as abrasive grains. The specific surface area of ​​diamond A was 0.17 (m 2 / g), the median diameter based on the number measured by laser diffraction is 52 μm, and the specific surface area of ​​Diamond B is 1.1 (m 2 / g), and the median diameter based on the number measured by laser diffraction is 5 μm. The specific surface area was calculated from the N2 adsorption isotherm (-196°C).

[0036] Furthermore, two sols were prepared: Alumina sol C (boehmite "F-1000" manufactured by Kawaken Fine Chemicals Co., Ltd.) and Alumina sol D (boehmite "F-3000" manufactured by Kawaken Fine Chemicals Co., Ltd.). Alumina sol C uses water as the liquid dispersion medium and contains 4.5 to 5.1 mass% of fibrous boehmite (AlO2H) with a minor axis of 4 nm and a major axis of 1400 nm. Alumina sol D uses water as the liquid dispersion medium and contains 4.5 to 5.5 mass% of fibrous boehmite with a minor axis of 4 nm and a major axis of 3000 nm. The boehmite in Alumina sol C and Alumina sol D is the raw fiber.

[0037] The aspect ratio of length / diameter of the boehmite in alumina sol C is 350. The aspect ratio of length / diameter of the boehmite in alumina sol D is 750.

[0038] These were mixed using a magnetic stirrer to obtain a first mixture (second step) so as to achieve the content (mass %) shown in Table 1. The content was determined by using the total mass of the abrasive grains and raw fiber as the denominator and the mass of the raw fiber as the numerator.

[0039] [Table 1]

[0040] Each first mixture was dropped onto a release film on a hot plate at 80°C, and after evaporating the water, it was further dried in a vacuum oven at 120°C to obtain a second mixture. The second mixture was then heated to 500°C at a rate of 10°C / min in the atmosphere and held there for 1 hour. In this way, the abrasives of Test Examples 1 to 8 and the Comparative Example were obtained (third step, sintering step).

[0041] FIG. 1 shows a field-emission scanning electron microscope photograph of the abrasive of Test Example 8 at 5,000x magnification, and FIG. 2 shows a field-emission scanning electron microscope photograph of the same abrasive at 150,000x magnification. Although the abrasive of Test Example 8 cannot be seen in FIG. 1, FIG. 2 shows that it comprises diamond abrasive grains and an adhesive material attached to the surfaces of the abrasive grains, with the adhesive material forming a mesh-like convex portion on the surface of the abrasive grains. It is clear that the adhesive material consists of long fibers. The fibers intersect on the surface of the abrasive grains to form multiple intersections, and it is clear that at least some of the intersections are sintered and bonded. The fibers are boehmite. The same is true for the abrasives of Test Examples 1 to 7.

[0042] On the other hand, the abrasive material of the comparative example does not use alumina sol C or alumina sol D and is therefore made up of only diamond abrasive grains.

[0043] In each of the abrasives of Test Examples 1 to 8 and the Comparative Example, the amount of fiber attached per unit BET surface area of ​​the abrasive grain (g / m 2 The results are also shown in Table 1.

[0044] Glass powder (TOMATEC Corporation "TMX-501F") was prepared, and a paste of the glass powder was printed on three alumina substrates. The abrasives of Test Examples 1 to 8 and the Comparative Example were each scattered on the paste to obtain unfired test pieces.

[0045] After drying the paste for each unsintered test piece, it was fired in air at 570°C for 2 hours to soften the glass powder, and then each unsintered test piece was cooled to room temperature. In this way, the abrasives of Test Examples 1 to 8 and the Comparative Example were fixed to the substrate using glass made from the glass powder, and each fired test piece was obtained. Excess abrasive was removed from each fired test piece, and multiple test pieces were obtained, each with one abrasive fixed to the substrate. In each test piece, the protruding height of the abrasive was 18 to 30 μm. Each test piece corresponds to a grinding wheel.

[0046] Using four test pieces for each test, the SiC wafer was ground two to four times under the following conditions, and the height of the abrasive before and after grinding and the grinding depth of the SiC were measured using a laser microscope to determine the amount of abrasive reduction (μm). The grinding depth was calculated as the average depth of both ends of each grinding mark.

[0047] Depth of cut: 2 μm Machining speed: 6mm / sec Processing distance: 5mm / pass x 20

[0048] The abrasive grain reduction rate was calculated as a relative value based on the abrasive grains of the comparative example using the following formula: Abrasive grain reduction rate = Abrasive grain reduction amount in each of Test Examples 1 to 8 / Abrasive grain reduction amount in Comparative Example

[0049] The abrasive grain reduction rate was evaluated according to the following criteria. The results are shown in Table 2. If the grain reduction rate is 0.9 or more, it is × If the grain reduction rate is 0.7 or more and less than 0.9, it is OK. If the grain reduction rate is less than 0.7, it is good.

[0050] [Table 2]

[0051] The relationship between the abrasive wear (μm) and the wafer processing amount (μm) for the abrasive of Test Example 4 and the abrasive of the Comparative Example is shown in Figure 3. In this case, the reduction amount required to process 1 μm of SiC was determined by linear interpolation of the points where the average values ​​were plotted.

[0052] Table 2 and Figure 3 show that the abrasive grain reduction rate is lower for abrasives in which boehmite fibers are attached to diamond abrasive grains. This is presumably because each fiber is not rounded like a metal layer or oxide microparticle layer, providing a stronger anchoring effect. Furthermore, because the long fibers only partially cover the abrasive grains, the abrasive grains have almost no effect on workability. Furthermore, this abrasive does not require a coupling agent to react with the abrasive grains; the abrasive grains can be used without any restrictions, as long as the fibers are attached to the surface of the abrasive grains.

[0053] However, the amount of each fiber attached to the abrasive grain is 0.65 g / m 2 The amount of each fiber attached to the abrasive grain is preferably less than 0.65 g / m 2 This is because the grain reduction rate in Test Example 6 was higher than in the Comparative Example, and the fibers had an effect on processability. In Test Example 6, it is thought that fiber agglomerations formed, creating gaps between the abrasive grains and the glass, which reduced the holding power.

[0054] In addition, as in Test Examples 2 to 5 and 7, the content of raw fiber was 0.02 to 5 mass % and the amount of attached fiber was 0.0012 to 0.31 g / m 2 In particular, as in Test Examples 3, 4, and 7, when the content of raw fiber is 0.2 to 1 mass % and the fiber adhesion amount is 0.012 to 0.29 g / m, the abrasive grain reduction rate is low and the abrasive grain reduction rate is excellent. 2 If the amount of fibers is this large, the abrasive grain reduction rate is particularly low and excellent, because the fibers cross and are particularly bonded on the surface of the abrasive grain. [Industrial Applicability]

[0055] The present invention can be used in a method for manufacturing a grinding wheel or the like.

Claims

1. abrasive grains and an adhesive material attached to the surface of the abrasive grains; The abrasive material is characterized in that the adhesive material has a mesh-like convex portion formed on the surface thereof.

2. 2. The abrasive according to claim 1, wherein said adhesive material is made of long fibers, and said convex portions are formed by crossing said fibers.

3. 3. The abrasive according to claim 2, wherein the fibers are bonded together at least at some of the intersections at which the fibers intersect.

4. 4. The abrasive material according to claim 2, wherein the diameter of the convex portion is 1 / 10 or less of the grain diameter of the abrasive grains.

5. 5. The abrasive according to claim 4, wherein the convex portions have a diameter of 1 nm to 5 μm.

6. 5. The abrasive according to claim 4, wherein the protrusions have a length of 50 nm or more.

7. 5. The abrasive material according to claim 4, wherein the protrusions have an aspect ratio of length to diameter of 20 or more.

8. The convex portions have a deposition amount of the abrasive grains per unit BET surface area of ​​0.001 to 0.4 g / m 2 3. The abrasive material according to claim 1 or 2, wherein

9. the abrasive grains are superabrasive grains, 4. The abrasive according to claim 2, wherein the fibers are made of an oxide or hydroxide of at least one of a metal and a semi-metal, or a mixture thereof.

10. 10. The abrasive according to claim 9, wherein the fibers are made of at least one of alumina and boehmite.

11. 3. The abrasive material according to claim 1, which is used for processing semiconductor wafers.

12. A first step of preparing abrasive grains and a sol in which elongated raw material fibers are dispersed in a liquid dispersion medium; a second step of mixing the abrasive grains and the sol to obtain a mixture; and a third step of removing the liquid dispersion medium from the mixture to obtain an abrasive comprising the abrasive grains and mesh-like protrusions formed by solidifying the raw fiber and adhering to the surfaces of the abrasive grains.

13. The method for producing an abrasive material according to claim 12, wherein the third step includes a sintering step of sintering the raw material fibers that intersect on the surface of the abrasive grain.

14. The method for producing an abrasive material according to claim 12 or 13, wherein the raw fiber has a diameter of 1 nm to 5 μm.

15. The method for producing an abrasive material according to claim 14, wherein the raw fiber has a length of 50 nm or more.

16. The method for producing an abrasive material according to claim 14, wherein the raw fiber has an aspect ratio of length to diameter of 20 or more.

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