JP3990936B2 - Abrasive grain and manufacturing method thereof, polishing tool and manufacturing method thereof, polishing grindstone and manufacturing method thereof, and polishing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polishing tool for finishing hard and brittle materials such as silicon and glass, and a metal material such as steel and aluminum, a manufacturing method thereof, abrasive grains for obtaining such a polishing tool, and a polishing tool. In particular, the present invention relates to a long-life polishing tool and a method for manufacturing the same for improving processing quality and efficiency.
[0002]
[Prior art]
Polishing using an abrasive slurry has been used for final finishing of parts made of various hard and brittle materials and metal materials such as silicon wafers and glass disks. Since this processing method is easy to use fine abrasive grains, an excellent finished surface can be easily obtained, and stable processing characteristics can be maintained by using a large amount of abrasive slurry. Widely used.
[0003]
However, a polishing process using such an abrasive slurry requires a large amount of slurry, and at the same time, discharges a large amount of slurry waste liquid, so that the load on the environment is extremely high and there is a limit to improving the processing efficiency. For these reasons, development of a fixed abrasive machining tool capable of obtaining an excellent finished surface equal to or better than the polishing finish using an abrasive slurry has been actively conducted in various fields.
[0004]
Here, in order to obtain a good machined surface roughness in the abrasive processing, it is advantageous to use fine abrasive grains, and fine abrasive grains are similarly used in fixed abrasive processing tools. However, in order to obtain an excellent machined surface such as a mirror surface, if a fixed abrasive machining tool having an abrasive grain size of several μm or less is used, the bonding material for bonding the abrasive grain and the substrate and the workpiece Contact occurs, and chips accumulate between the abrasive grains, resulting in clogging. As a result, the machining resistance increases rapidly, and in the worst case, machining becomes impossible.
[0005]
Here, even when measures are taken to suppress contact between the abrasive grain binder and the workpiece, there is a problem that the machining efficiency is lowered because the abrasive grain size is small.
[0006]
On the other hand, in order to improve the machining efficiency, it is necessary to select abrasive grains having a large particle diameter. In this case, although the machining efficiency is improved, the quality of the machined surface is lowered and it is difficult to obtain a mirror surface.
[0007]
In order to solve these problems, fixed abrasive processing tools that use fine powder grains and agglomerated powder as abrasive grains are disclosed in JP-A-7-164324, JP-A-8-155840, Japanese Laid-Open Patent Publication No. 9-504235, Japanese Patent Application Laid-Open No. 2000-198073, Japanese Patent Application Laid-Open No. 2000-237962, Japanese Patent Application Laid-Open No. 2000-176842, Japanese Patent Application Laid-Open No. 2001-129964, and the like. In these fixed abrasive processing tools, excellent surface roughness is obtained by the action of the fine abrasive grains, and at the same time, improvement of processing efficiency due to aggregated abrasive grains is realized.
[0008]
However, when trying to further improve the processing efficiency, these technologies do not pay attention to the bonding force between the fine particles that make up the abrasive grains. It has been found that problems such as inadequate tool life occur.
[0009]
[Problems to be solved by the invention]
The present invention improves the above-mentioned conventional problems, that is, abrasive grains capable of maintaining polishing processing with extremely high processing efficiency for a long time without sacrificing the roughness of the processed surface, and such abrasive grains An object of the present invention is to provide a long-life polishing tool and polishing apparatus using the above.
[0010]
[Means for Solving the Problems]
Regarding the fixed abrasive processing tool using the above-mentioned prior art, which is agglomerated fine abrasive grains and using the agglomerated powder as abrasive grains, as a result of further earnest research by the inventors, However, it has been found that the bonding force between the fine particles constituting the abrasive grains is basically a very important factor. That is, in these prior arts, no attention or consideration has been given to the bonding force between the fine particles constituting the agglomerated abrasive grains.
[0011]
Here, the abrasive grains gradually wear and become flattened as a result of use in the polishing / grinding process, but the flat or substantially flat surface generated by this flattening is the processed surface. is there.
[0012]
In the case of abrasive grains made of sintered ceramic, high polishing efficiency can be obtained, but since there is no void and it is too hard, processing creates a new large scratch on the work surface. Deteriorates surface roughness.
[0013]
On the other hand, in the case of abrasive grains composed of secondary particles formed by agglomerating fine primary particles, a kind of cutting edge is formed by the primary particles and the space, so that high polishing quality is obtained. .
[0014]
However, in such abrasive grains composed of secondary particles formed by agglomeration of such fine primary particles, the primary particles are too fine or the bonding between the primary particles is not controlled, so that high polishing efficiency is obtained. Moreover, durability and life sufficient for practical use cannot be obtained.
[0015]
Here, in the abrasive grains formed by collecting fine particles, the inventors can gradually advance the wear of the abrasive grains by processing by appropriately adjusting the bonding force between the fine particles. As a result, new cutting edges are always generated, and it is possible to maintain excellent machining characteristics for a long time with high machining efficiency for the work piece and high machining surface quality of nanometer order. At the time, it was found that the wear of the abrasive grains itself is suppressed, so that the tool life can be prolonged as a result.
[0016]
  That is, the abrasive grains of the present invention, as described in claim 1, in order to solve the above problems, secondary particles formed by aggregation of a large number of primary particles,A porous abrasive formed by heating at a temperature at which a neck is formed at the bonding point between the primary particles to grow primary particles inside the secondary particles,
(B) Cutting edge forming particles formed by the growth of the primary particles are loosely coupled to each other by the neck, (b) voids are formed between the cutting edge forming particles, and (c) the neck is a single leaf hyperboloid. And (d) the pore specific surface area of the porous abrasive grains is 18000 cm. ² / Cm ³ More than 700000cm ² / Cm ³ Has been belowIt is the abrasive grain characterized by this.
[0017]
  According to such a configuration, the abrasive grains are used during actual use.,At least a part of the processed surface that is in contact with the gap of the cutting edge forming particle functions as a cutting edge, and the cutting edge forming particle is worn out and lost as the cutting edge is lost. Has a function of sequentially projecting to the work surface, and during polishing and grinding, the abrasive grains always have a self-generated blade, good chip removal, excellent quality while maintaining excellent quality, and Processing can be carried out stably over a long period of time.
  Furthermore, the abrasive grain of claim 1 has a pore specific surface area of 18000 cm. ² / Cm ³ More than 700000cm ² / Cm ³ In order to have the configuration described below, the wear of the abrasive grains themselves and the degree of dropout that occurs as the cutting edge forming particles wear and lose the part that becomes the cutting edge are optimized, and a good machined surface quality is achieved. It is possible to process with higher efficiency while maintaining it, and at the same time, it is possible to suppress abrasive wear, so that it is possible to make an abrasive with a good balance between processing efficiency, processing quality and long life, and it has such an abrasive The life of the polishing tool can be further increased.
  Here, the pore specific surface area of the abrasive grains is 18000 cm. ² / Cm ³ If it is less than this, scratches are likely to occur on the machined surface, which may deteriorate the quality of the machined surface. Conversely, the pore specific surface area is 700,000 cm. ² / Cm ³ Larger than that, the binding force between the cutting edge forming particles is too weak, so that sufficient polishing and grinding cannot be performed, and conversely, the abrasive grains themselves are heavily worn, and the processing efficiency is extremely reduced. There is a possibility that the pre-processed surface of the workpiece cannot be completely removed. Further, when applied to a grindstone, grinding burn tends to occur.
[0018]
Invention of Claim 3 has the structure whose compressive fracture strength is 1 Mpa or more and 500 Mpa or less in the abrasive grain of Claim 1 or Claim 2. According to the invention of claim 3, as the abrasive grains, the wear of the abrasive grains themselves and the degree of dropout that occurs as the cutting edge forming particles wear and lose the portion that becomes the cutting edge are optimized and good It is possible to process with higher efficiency while maintaining a good machined surface quality, and at the same time, it is possible to suppress wear of abrasive grains, so that it is possible to make abrasive grains with a good balance between machining efficiency, machining quality and long life, like this The life of a polishing tool having a proper abrasive grain can be further extended.
[0019]
Here, if the compressive fracture strength of the abrasive grains exceeds 500 MPa, scratches are likely to occur on the processed surface, which may deteriorate the quality of the processed surface. On the other hand, when the compressive fracture strength is less than 1 MPa, the binding force of the cutting edge forming particles is too weak, so that sufficient polishing and grinding cannot be performed, and conversely, the abrasive grains themselves are severely worn, There is a possibility that the processing efficiency is extremely lowered and the pre-processed surface of the workpiece cannot be completely removed. Further, when applied to a grindstone, grinding burn tends to occur.
[0020]
Grinding burn is a phenomenon that occurs when contact between the binder that fixes the abrasive grains and the workpiece does not occur in the grinding wheel, and normal grinding can be performed at this time. This means that the temperature of the ground surface rises and discoloration occurs on the ground surface.
[0021]
Invention of Claim 4 has the structure whose compressive fracture strength is 20 Mpa or more and 300 Mpa or less in the abrasive grain of Claim 3. According to the invention described in claim 4, it is possible to perform processing with higher efficiency while maintaining high processing surface quality, and at the same time, it is possible to suppress wear of abrasive grains more effectively and to have such abrasive grains. The life of the polishing tool can be further increased.
[0024]
  Claim5The invention of claim 1Or any one of claims 3In the abrasive described in the above, the pore specific surface area is 100,000 cm.²/ Cm³More than 300,000cm²/ Cm³It has the following configuration. Such claims5According to the described invention, it is possible to process with higher efficiency while maintaining high processing surface quality, and at the same time, it is possible to more effectively suppress the wear of abrasive grains, and to further improve the life of a polishing tool having such abrasive grains. Can be long.
[0025]
  Claim6The invention of claim 1 to claim 15Either1 itemThe abrasive grains described in 1 above have a configuration in which the average particle diameter of the cutting edge forming particles is 5 μm or less.
  Such claims6According to the described invention, excellent processing quality can be obtained with certainty. Here, if the average particle size of the cutting edge forming particles exceeds 5 μm, scratches may occur on the processed surface, which may reduce the processing quality, which is not preferable. Here, in order to prevent the average particle diameter of the cutting edge forming particles from exceeding 5 μm, it can be achieved by adjusting the heat treatment conditions.
[0026]
  And claims7The invention described in claim 1 to claim6Either1 itemThe abrasive described in 1 above has a configuration that does not include a binder for bonding the cutting edge forming particles to each other.
[0027]
With such a configuration, the cutting edge forming particles are worn away and lost as the cutting edge is lost, and when new cutting edge forming particles are sequentially projected onto the work surface, the binder of the cutting edge forming particles is used. The amount of protrusion from the surface does not become insufficient, and the occurrence of scratches due to clogging, clogging, residual binder or chip adhesion to the binder can be avoided. it can.
[0028]
  In order to obtain an excellent abrasive grain as described above, the method for producing an abrasive grain of the present invention claims8As described inA step of aggregating a large number of primary particles to obtain secondary particles, and heat-treating the secondary particles at a temperature at which a neck is formed at a bonding point between the primary particles to grow the primary particles ( (B) Cutting edge forming particles formed by the growth of the primary particles are loosely coupled to each other by the neck, (b) voids are formed between the cutting edge forming particles, and (c) the neck has a single leaf hyperboloid shape. And (d) the pore specific surface area of the porous abrasive is 18000 cm. ² / Cm ³ More than 700000cm ² / Cm ³ Obtaining porous abrasive grains as described below;Have
[0029]
According to such an abrasive grain manufacturing method of the present invention, the abrasive grains obtained by such two steps are used on the processed surface as described in claim 2 when used as actual abrasive grains. At least a portion of the cutting edge forming particle that contacts the gap functions as a cutting edge, and the cutting edge forming particle wears out and loses as the cutting edge is lost. It has a function to protrude sequentially, and during polishing and grinding, the abrasive grains are always formed spontaneously, chip removal is good, excellent quality is maintained with excellent quality, and for a long time. Processing can be carried out stably over the entire time.
[0030]
  Claim at this time9It is desirable to perform the heat treatment under the condition that the average particle diameter of the cutting edge forming particles formed as described in the above is 5 μm or less. That is, if the average particle size of the cutting edge forming particles exceeds 5 μm, scratches may occur on the processed surface and the processing quality may deteriorate, which is not preferable.
[0031]
  Claims10Such claims as in the polishing tool as described.6Either1 itemThe polishing tool having the abrasive grains described in 1 above on the polishing surface can be processed efficiently and stably for a long time while maintaining excellent quality by the excellent abrasive grains according to the present invention. be able to.
[0032]
  Claims11The polishing tool according to claim 1,10In the polishing tool described in item 1, the abrasive grains are exposed on the polishing surface of the polishing tool. With such a configuration, it is possible to prevent deterioration of processing quality due to the binder that fixes the abrasive grains or the abrasive grains and the base material that supports the abrasive grains. Here, as the binder, any one or more of resin, ceramic, and metal can be used. For example, a ceramic precursor may be used and then ceramic may be formed by heat treatment.
[0033]
  Claims12The polishing tool according to claim 1,10Or claims11The polishing tool according to item 1, wherein the polishing tool is any one of a polishing film, a polishing cloth, and a polishing grindstone. Since the polishing tool is any one of the polishing film, the polishing cloth, and the polishing grindstone as described above, the polishing tool according to any one of claims 1 to 7 has high processing efficiency and high quality. The effect of enabling processing can be exhibited particularly effectively.
[0034]
When used as an abrasive film, the effect of the abrasive grains can be sufficiently obtained, and the abrasive film itself is an inexpensive abrasive tool, so that it can be used at a relatively low cost even under so-called disposable or nearly disposable conditions. It is possible to perform the polishing process.
[0035]
In the case of an abrasive cloth, it is possible to sufficiently obtain the effect of the abrasive grains, and can be used as a tool in place of the surface plate in a conventional polishing machine or lapping machine, In contrast, since new abrasive grains appear on the surface of the polishing tool with wear, it can be used for a long time. Therefore, the workpiece can be efficiently and finished with excellent surface quality, and the tool life is long, so that the tool cost is reduced and the burden on the operator such as tool replacement can be reduced at the same time.
[0036]
Further, by applying to a grinding wheel and adding it to the grinding wheel, the workpiece can be finished stably and efficiently with excellent work surface quality without causing grinding burn during polishing and grinding.
[0037]
  Claims13The polishing tool according to claim 1,12In the polishing tool according to item 1, the polishing tool is a polishing film, and the thickness of the binder layer for fixing the abrasive grains to the base film is smaller than the maximum diameter of the abrasive grains. With such a configuration, it is possible to prevent the polishing quality from being deteriorated due to the binder coming into contact with the surface to be polished, and to guarantee the protrusion amount of the abrasive grains.
[0038]
  Claims14The polishing tool according to claim 1,10Or claims13Either1 itemThe abrasive | polishing tool as described in 5 is characterized by the content rate of the said abrasive grain in the part which has an abrasive grain being 5 volume% or more and 90 volume% or less. With such a configuration, it is possible to obtain excellent processed surface quality with high efficiency. If the content of the abrasive grains is less than 5% by volume, the effect of addition may not be sufficiently obtained. On the other hand, if the content exceeds 90% by volume, the amount of the binder in the polishing tool is too small, and the abrasive grains. The holding strength is significantly lowered and cannot be used as a polishing tool.
[0039]
  Claims15The method of manufacturing an abrasive tool includes a step of aggregating a number of primary particles to obtain secondary particles;SaidHeat treatment of the secondary particles at a temperature at which a neck is formed at the bonding point between the primary particles,SaidBy growing primary particles,(B) Cutting edge forming particles formed by the growth of the primary particles are loosely coupled to each other by the neck, (b) voids are formed between the cutting edge forming particles, and (c) the neck is a single leaf hyperboloid. And (d) the pore specific surface area of the porous abrasive grains is 18000 cm. ² / Cm ³ More than 700000cm ² / Cm ³ Obtaining porous abrasive grains as described below, fixing the abrasive grains to a substrate,Have With such a configuration, it is possible to easily obtain a long-life polishing tool that can be polished extremely efficiently while maintaining excellent quality.
[0040]
  Claims15In the manufacturing method of the polishing tool,16As described in,In the step of fixing the abrasive grains to the substrate, a polishing tool satisfying required heat resistance, strength, etc. can be obtained by using one or more binders selected from resin, ceramic and metal. It is also possible to improve the adhesion with the binder by modifying the surface of the abrasive grains used at this time.
[0041]
As a fixing method, for example, a mixture of a binder and abrasive grains can be applied to a substrate using, for example, a wire bar coater, a gravure coater, a reverse roll coater, a knife coater, or the like.
[0042]
  And this claim16In the manufacturing method of the polishing tool,17As described above, in the step of fixing the abrasive grains to the base material, a polishing tool having a long life can be obtained by fixing the abrasive grains together with the reinforcing material to the base material. Here, the reinforcing material is claimed.18As described in (1), inorganic fibers such as metal powder, carbon fiber, and glass fiber, organic fibers such as polyacrylonitrile fiber, and metal fibers can be used. When using a fiber, it can be used as appropriate length, such as a chopped fiber and a milled fiber, if necessary. Further, the surface of these fibers can be modified to improve the adhesion to the binder. In addition to the above, various whiskers can be used as the reinforcing material.
[0043]
  Claims19The manufacturing method of the polishing tool according to claim15Or claims18In the method for producing an abrasive tool according to any one of the above, the abrasive tool is an abrasive film or an abrasive cloth.
[0044]
  Claims20The manufacturing method of the grinding wheel for polishing described inA step of aggregating a large number of primary particles to obtain secondary particles, and heat-treating the secondary particles at a temperature at which a neck is formed at a bonding point between the primary particles, thereby growing the primary particles ( (B) Cutting edge forming particles formed by the growth of the primary particles are loosely coupled to each other by the neck, (b) voids are formed between the cutting edge forming particles, and (c) the neck has a single leaf hyperboloid shape. And (d) the pore specific surface area of the porous abrasive is 18000 cm. ² / Cm ³ More than 700000cm ² / Cm ³ A step of obtaining porous abrasive grains as described below, a step of mixing or kneading the binder for bonding the abrasive grains and the abrasive grains to obtain an abrasive grain mixture material, and molding the abrasive grain mixture material And a process of making a grinding wheelThis is a method for manufacturing a grinding wheel. By such a manufacturing method, it is possible to easily obtain a grinding wheel that can be processed very efficiently while maintaining excellent quality. Here, as the binder, any one or more of resin, ceramic, and metal can be used, and for example, a ceramic precursor may be used and then the ceramic may be formed by heat treatment.
[0045]
  Further claims21In the method for producing a grinding stone according to claim 2,20In the step of mixing or kneading the abrasive grains and a binding material for bonding the abrasive grains to obtain an abrasive grain mixed material as described in 1., improving the rigidity and wear resistance by adding a reinforcing material In addition, a grinding wheel having a longer life can be obtained. At this time, the claim22As described above, examples of the reinforcing material include organic fibers, inorganic fibers, and metal fibers, and these fibers can be used as appropriate lengths such as chopped fibers and milled fibers, if necessary. Further, the surface of these fibers can be modified to improve the adhesion to the binder. Moreover, various whiskers etc. can also be used as a reinforcing material.
  Furthermore, it is possible to improve the adhesion with the binder by modifying the surface of these reinforcing materials.
[0046]
  Claims23The polishing apparatus according to claim 1, wherein10Or claim 14Either1 itemThe polishing tool described in 1. is provided. Such a polishing apparatus has high polishing efficiency and polishing quality, and the life of the polishing tool is long.
  Such a polishing tool can be processed with high processing efficiency and high quality, and has a long life.
[0047]
DETAILED DESCRIPTION OF THE INVENTION
The abrasive grains of the present invention are obtained by heat-treating secondary particles formed by aggregation of a large number of primary particles at a temperature at which a neck is formed at the bonding point between the primary particles. A granular porous body in which particles are partially and loosely bonded to each other, and this cutting edge forming particle is an abrasive formed by growing primary particles during the heat treatment. It is a grain.
[0048]
In this way, unlike abrasive grains made of secondary particles formed by simply agglomerating conventional fine primary particles, a large number of fine cutting edge forming particles partially form voids, While maintaining the structure of a granular porous body that is loosely bonded to each other, compared to the bonding of primary particles in the conventional abrasive grains, the cutting edge forming particles formed by growing primary particles by heat treatment Since the neck is formed in the joint portion, the joint is strong, so that it can be used for a long time while having polishing efficiency and polishing quality.
[0049]
The cutting edge forming particles in the present invention are particles in which primary particles in secondary particles formed by aggregation of a large number of primary particles are grown by heat treatment, and at least a part of the particles is used for polishing and grinding. A particle that sometimes acts on a workpiece as a cutting edge on the workpiece.
[0050]
Furthermore, according to the heat treatment in which the primary particles grow as described above, not only the primary particles grow due to the mass transfer of the substances constituting the particles, but also the bonding points between the particles are the mass transfer of the substances forming the particles. Becomes a gentle curved surface with no discontinuities, and a so-called “neck” shape constricted in a one-leaf hyperboloid shape (a drum shape). Regarding the growth of primary particles and the formation of “neck” by mass transfer during the heat treatment, “2. Ceramic material technology collection” issued by the Industrial Technology Center Co., Ltd. (first edition issued on April 10, 1979) “2. 3 “Mass transfer mechanism and sintering model”.
[0051]
In the present invention, since the cutting edge forming particles are bonded to each other from the substance constituting the cutting edge forming particles as described above, no binder is included as abrasive grains. As the blade part is lost, it falls off and new cutting edge forming particles are sequentially projected onto the machined surface, so that the cutting edge forming particles protrude from the binder when the abrasive grains are formed using the binder. It is possible to avoid problems such as generation of scratches due to generation of scratches due to insufficient amount, clogging, clogging, residual binder, and chip adhesion to the binder.
[0052]
However, when forming a secondary particle by aggregating a large number of primary particles with each other, a binder made of, for example, an organic substance that completely disappears due to oxidation, decomposition, evaporation, etc. by heat treatment can be used. In that case, since the binder does not remain at the time of use as abrasive grains, the above inconvenience is avoided.
[0053]
By combining the particles with each other in a neck shape, the bonding strength between the cutting edge forming particles is strengthened. As a result, coupled with the growth of the particles themselves, the processing efficiency is high and the quality is high. It is possible to obtain abrasive grains that can be processed for a long time while being able to be processed smoothly.
[0054]
In the present invention, the raw material constituting the primary particles is a hard inorganic material having physical properties that can be accepted when it is used as abrasive grains. Any material may be used, and examples thereof include silica, ceria, cubic boron nitride (cBN), alumina, silicon carbide, zirconium oxide, and the like. It is desirable to use a primary particle having an average particle size of 5 μm or less. .
[0055]
The secondary particles in the present invention are aggregates composed of a large number of fine primary particles.
As a method of aggregating a large number of fine primary particles with each other to obtain such secondary particles, a spray dryer (generally, a size of 1 μm to 300 μm is obtained. When the particle size distribution is not sharp, a classification process is added. ), A sol-gel method, a freeze drying method using a solvent together, a solvent drying method, and the like. Further, evaporation-aggregation, gas phase decomposition, other gas phase reactions, and the like can be used as a method utilizing thermal decomposition and solid phase reaction of a solid or a method of forming from gas.
[0056]
The secondary particles obtained as described above are subjected to heat treatment to grow primary particles in the secondary particles. The heat treatment in the present invention needs to be performed under conditions (temperature, time) in which primary particles in secondary particles formed by aggregation of a large number of primary particles grow as described above.
[0057]
The conditions for the heat treatment are appropriately selected depending on the material constituting the primary particles, but usually a temperature at which the heat treatment is completed within 10 minutes to several hours is selected. If the heat treatment time is too long, it becomes difficult to control, and it will sinter like normal ceramic abrasive grains. If the result is the same as that obtained, the effect of the present invention cannot be obtained.
[0058]
Here, a heat treatment test is performed at several different temperatures and times in advance, and the structure inside the treated particles is observed with an electron microscope or the like. It is in the range of the so-called “neck” -shaped condition (indicating that the primary particles have grown), which are narrow and curved in a single-leaf hyperboloid shape, and a large number of fine cutting edge forming particles are partially In addition, a condition in a range in which a granular porous body structure formed by forming voids and loosely bonding to each other is maintained is searched for.
[0059]
Although these temperatures and times vary greatly depending on the material, the materials exemplified above are generally 500 to 1600 ° C. and several minutes to 24 hours. At this time, it is also possible to pressurize as necessary.
[0060]
However, if the cutting edge forming particles constituting the abrasive grains grow and become too large, the balance may be lost, and the effects of the present invention may not be obtained. It is desirable that the average particle size is 5 μm or less.
[0061]
In the above heat treatment, the abrasive grains obtained have a compressive fracture strength of 1 MPa to 500 MPa, or a pore specific surface area of 18000 cm.²/ Cm^ThreeMore than 700000cm²/ Cm^ThreeIt is preferable to carry out under the following conditions. At this time, it is possible to polish the high processing surface quality with higher efficiency, and at the same time, it is possible to suppress the abrasion of the abrasive grains, and it is possible to use the abrasive tool having the abrasive grains for a longer period of time, and the trouble of replacing the abrasive tool It is possible to reduce the cost required for exchanging the polishing tool.
[0062]
【Example】
Hereinafter, the abrasive grains of the present invention will be described with specific examples. However, the present invention is not limited to these examples, and various modifications can be made without departing from the scope of the present invention.
[0063]
In the present invention, the average particle size is measured by dry using a laser diffraction / scattering particle size distribution analyzer LA-920 manufactured by HORIBA, Ltd., and the average particle size (with 50% frequency integration) ( Usually called median diameter).
[0064]
In addition, the compressive fracture strength test was performed using a micro compression tester MCTM500PC manufactured by Shimadzu Corporation based on a report by Hiramatsu, Oka and Kiyama (Journal of the Japan Mining Association, 81, 1024 (1965)).
[0065]
As test conditions, the test load is 10 to 1000 mN, the load speed is 0.446 mN / sec, the measured granule is compressed using a flat indenter, and the strength when the granule is broken by the compression is measured. . The relationship between the compression displacement and the load at this time is schematically shown in FIG.
The compressive fracture strength was calculated by reading the load value at the curved refracted portion within the broken line circle in FIG.
[0066]
On the other hand, the surface roughness of the processed surface was evaluated using Foam Talysurf S4C manufactured by Taylor Hopson.
The pore specific surface area in the present invention was a value obtained by multiplying the BET specific surface area measured by the nitrogen gas adsorption / desorption BET one-point method at a relative pressure of 0.3 by the density of the material constituting the abrasive grains.
[0067]
[Example 1]
Ultrafine zirconium oxide (ZrO) having a particle size of 50-60 nm₂) The powder was added with water (an aqueous binder such as a polyvinyl alcohol-water mixture may be used) to form a slurry, which was sprayed with a spray dryer to obtain secondary particles α having an average particle size of 50 μm. The compressive fracture strength of the secondary particles α was 0.47 MPa. 2 and 3 show a scanning electron microscope (SEM) photograph of the entire secondary particle α and a partially enlarged scanning electron microscope (SEM) photograph.
[0068]
The secondary particles α were heated in an electric furnace. By this heat treatment, the polyvinyl alcohol used as the binder when forming the secondary particles as described above is completely removed.
[0069]
The heat treatment temperature and the heat treatment time were adjusted so that the internal particles inside the porous granule functioning as cutting edge forming particles when used as abrasive grains were 5 μm or less in accordance with the conditions examined in advance.
FIG. 4 shows a partially enlarged SEM photograph (same magnification as FIG. 3) of an example of the porous particles (abrasive grains β) made of zirconium oxide, which was heat-treated under appropriate conditions.
[0070]
According to FIG. 4, the porous particles functioning as cutting edge forming particles when used as abrasive grains are clearly grown larger than the primary particles shown in FIG. It can be confirmed that it is constricted, so-called “neck”, and that a large number of fine cutting edge forming particles are partially and loosely bonded to each other to form voids. In the heat treatment, if the time is too long or the temperature is too high, the primary particles are completely bonded to each other and a nearly complete sintered body is obtained.
[0071]
The abrasive grains β according to the present invention having an average particle diameter of 50 μm and a compression fracture strength of 92.6 MPa thus obtained were mixed with a liquid urethane resin so that the volume ratio of the particles was 35% by volume, Methyl ethyl ketone was added as a solvent to adjust the solution viscosity, and then mixed and stirred for about 10 minutes using a stirrer to prepare a mixture. Stirring was performed at 50 rpm at room temperature and with a rotational speed that did not destroy the abrasive grains.
[0072]
This mixture was coated on a substrate (applied to a PET film having a thickness of about 75 μm using a wire bar coater, and then dried in a thermostatic bath maintained at 60 ° C. for 1 hour to obtain a polishing film A as a polishing tool. .
[0073]
The maximum thickness of the obtained coating layer (part having the abrasive grains) is approximately equal to the maximum diameter of the abrasive grains according to the present invention having a particle size distribution (the binder layer by using a solvent as described above) It is easy to reduce the thickness of the). The result of processing the optical glass disk (borosilicate crown glass (BK7 equivalent)) having a diameter of 30 mm, adjusted so that the maximum height roughness Ry is 2 μm, by mounting the polishing film A thus prepared on a lapping platen. (Processing conditions: platen rotational speed 60 rpm, processing pressure 46 kPa) A mirror surface having no scratch and a maximum height roughness Ry of 30 nm or less could be obtained in 2 minutes.
[0074]
Further, even when 20 similar glass disks were subsequently processed under the same conditions, there was almost no decrease in processing efficiency or processed surface roughness. Here, the surface enlarged photograph before processing of the glass disk is shown in FIG. 5, the surface roughness measurement result (chart) at that time is shown in FIG. 6, and the surface enlarged photograph after processing (the same magnification as FIG. 5). The surface roughness measurement results are shown in FIGS. 7 and 8, respectively.
From these, it can be seen that the irregularities that existed before the processing are almost eliminated after the processing, and have a mirror surface.
[0075]
Further, the abrasive wear state on the polishing film A after processing 10 glass disks was examined. The state of the surface is shown in FIG.
From FIG. 9, it can be seen that since the binding force between the cutting edge forming particles is appropriate, the wear gradually progresses as the processing progresses, and there is no major breakage in the abrasive grains or dropping off from the base material.
[0076]
[Comparative Examples 1-2]
Similar to the preparation of the abrasive grains β using the secondary particles α in Example 1, except that the heat treatment conditions were changed, the compression fracture strength was 0.6 MPa, and the pore specific surface area was 1000000 cm.²/ Cm^ThreeAbrasive grains γ and compressive fracture strength of 613 MPa and pore specific surface area of 3000 cm²/ Cm^ThreeAn abrasive grain δ was obtained. Both of these average particle diameters were 50 μm.
[0077]
When these abrasive grains γ and δ were observed with a scanning electron microscope, the abrasive grains δ having a compressive fracture strength of 0.6 MPa showed no “neck” formation, and the primary particles grew with insufficient heat treatment. I found that it was not. On the other hand, in the abrasive grain δ having a compressive fracture strength of 613 MPa, there are no structures in which a large number of fine cutting edge forming particles are partially and loosely bonded to each other, and are almost completely sintered. It was.
[0078]
Each of these two types of abrasive grains γ or δ was used in the same manner as the abrasive film A, and the abrasive film B (compressive fracture strength of the abrasive grains γ: 0.6 MPa, Comparative Example 1) and abrasive film C (abrasive) Compressive fracture strength of grain δ: 613 MPa, Comparative Example 2) was produced. These polishing films B and C were respectively attached to the lapping machine in the same manner, and processing was performed on the BK7 optical glass disk adjusted to have a maximum height roughness Ry of 2 μm under the same processing conditions.
In the case of the polishing film B, processing was performed for 20 minutes, but the maximum height roughness Ry could only reach 1.275 μm.
[0079]
Further, when a processing test was similarly performed using an abrasive film prepared using secondary particles α (compression fracture strength 0.47 MPa) that had not been subjected to heat treatment, the processing efficiency was further improved as compared with the results with the abrasive film B. However, the pre-processed surface could not be improved.
[0080]
FIG. 10 shows an enlarged photograph of the surface of the glass disk before processing, FIG. 11 shows the surface roughness measurement result, and an enlarged photograph of the surface after processing for 20 minutes (the magnification is the same as FIG. 10). ) And the surface roughness measurement results are shown in FIGS. 12 and 13, respectively.
Moreover, the state of the abrasive grains on the polishing film B after processing use is shown in FIG.
[0081]
From these results, although the surface roughness of the glass disk was somewhat improved by polishing for 20 minutes using the polishing film B, the abrasive grains themselves were severely worn (see FIG. 14), and the pre-processed surface of the glass disk was completely It can be seen that it has not been removed.
[0082]
On the other hand, when the polishing film C is used, since the abrasive grains are formed into a completely sintered body in which primary particles are completely bonded to each other, a large scratch is newly generated by processing on the surface of the glass disk. The maximum height roughness Ry was rather deteriorated to 2.7228 μm (FIG. 15 shows an enlarged surface photograph (scratches are visible), and FIG. 16 shows the surface roughness measurement result (the presence of scratches is confirmed). In addition, the abrasive grains themselves were not so worn, and the tip portion was not flattened even by microscopic observation.
[0083]
Similarly, polishing films having abrasive grains having various compressive fracture strengths were prepared, and the relationship between the compressive fracture strength, the processed surface roughness (symbol: □), and the processing efficiency (symbol: ◇) was examined. The results are shown in FIG. The machining efficiency on the vertical axis in FIG. 17 indicates the amount of grinding per unit time relatively, and the machining efficiency increases as it goes up in the graph.
[0084]
From FIG. 17, when the compressive fracture strength is too small (compressive fracture strength: less than 1 MPa), that is, when the binding force of the cutting edge forming particles is too weak, the processing efficiency is low, and the fracture of the abrasive grains themselves by the processing pressure proceeds. Therefore, since the pre-processed surface cannot be completely removed, the processed surface roughness is hardly improved. On the other hand, when the compressive fracture strength is too high, for example, in the case of a nearly perfect sintered body (compression fracture strength: 613 MPa), the processing efficiency is remarkably increased, but on the other hand, the quality of the processed surface is greatly deteriorated. As described above, only the abrasive grains according to the present invention having an appropriate binding force of the cutting edge forming particles can achieve high machining surface quality (mirror surface) with high efficiency. At that time, it was found that the wear of the abrasive grains itself was suppressed and the life of the polishing tool was extended.
[0085]
FIG. 18 shows the relationship between the pore specific surface area, which is a parameter representing the internal structure of the abrasive grains, and the processing efficiency of the abrasive grains having various compressive fracture strengths in FIG. Here, the pore specific surface area is a normal specific surface area (unit: “cm²/ G "or" m "²Unlike “/ g” and the like, the influence of the difference in the specific gravity of the material is excluded, and thus the parameter indicates the difference in the internal structure more prominently. Further, the processing efficiency on the vertical axis in FIG. 18 indicates the amount of grinding per unit time relatively, and the processing efficiency is higher as it is higher in the graph.
[0086]
From FIG. 18, when the heat treatment effect is not sufficiently exhibited and the pore specific surface area is too large (pore specific surface area: 700,000 cm).²/ Cm^ThreeSuper), that is, if the bonding force of the cutting edge forming particles is too weak, the machining efficiency is low, and the destruction of the abrasive grains themselves due to the machining pressure progresses, so the pre-machined surface cannot be completely removed. Roughness is hardly improved. On the other hand, a structure in which the pore specific surface area is too small and a large number of fine cutting edge forming particles are partially and loosely bonded to each other is lost. Sintered body (pore specific surface area: 5000 cm²/ Cm^ThreeIn the case of the following), the machining efficiency is remarkably increased, but the machined surface quality is greatly deteriorated. Thus, only the abrasive grains according to the present invention having an appropriate binding force of cutting edge forming particles and a specific structure can achieve high machining surface quality (mirror surface) with high efficiency. At that time, it was found that the wear of the abrasive grains itself was suppressed and the life of the polishing tool was extended.
[0087]
[Example 2]
Silica abrasive grains having a primary particle diameter (average particle diameter of 50 nm) made of colloidal silica are aggregated so as to have an average particle diameter of 30 μm by a sol-gel method, and the resulting silica powder is dried to obtain moisture contained in the pores. Then, the organic solvent was removed to obtain secondary particles ε.
[0088]
The secondary particles ε thus obtained were subjected to heat treatment under various conditions, followed by observation with a scanning electron microscope. Among these, a large number of fine cutting edge forming particles were partially and In the present invention, the present invention is a granular porous body in which voids are formed and loosely bonded to each other, and the cutting edge forming particles are granular porous formed by growing primary particles during the heat treatment. Such abrasive grains ζ were obtained.
The compression fracture strength of the abrasive grains ζ was 124.2 MPa, and the size of the cutting edge forming particles was 1.2 μm.
[0089]
The obtained abrasive grains ζ are mixed with a polyurethane resin so that the volume ratio is 35% by volume, and the copper powder (reinforcing material) having an average particle diameter of 3 μm is 15% by volume, and stirred. The mixture was mixed and stirred at 60 rpm for 15 minutes by a machine to obtain a mixture (in this case, a foaming agent for forming closed cells may be added as necessary).
[0090]
This mixture was poured into a circular mold (450 mmΦ), and then cured by heat treatment at 120 ° C. for 10 hours to obtain an abrasive cloth. The obtained polishing cloth was cut into a predetermined size and pasted on a surface plate, and a silicon wafer having a diameter of 30 mm, which had been ground in advance with a grindstone equivalent to # 2000, was polished.
[0091]
As a result, a mirror surface having a processed surface maximum height roughness Ry of 20 nm or less without scratches was obtained after processing for 10 minutes. Further, even when 20 silicon wafers were subsequently polished, no reduction in processing efficiency or surface roughness was observed.
[0092]
FIG. 19 schematically shows an example in which the polishing cloth according to the present invention used in Example 2 is attached to a polishing apparatus for silicon processing which is a polishing apparatus.
In the figure, reference numeral 1 denotes a silicon wafer which is a workpiece. The silicon wafer 1 is attached to a rotating unit 10 and is rotated by the rotation of the rotating unit 10. The polishing cloth according to the present invention (which may be fixed in place of the polishing cloth) fixed on the surface plate 20 according to the movement of the direction is contacted, and the lower surface thereof is polished. Since the surface plate 20 also rotates, the entire lower surface of the silicon wafer 1 is uniformly polished.
[0093]
[Example 3]
Polishing of silica abrasive grains having a compressive fracture strength of 18.5 MPa and a cutting edge forming particle size of 0.2 μm obtained by subjecting the secondary particles ε to heat treatment under conditions different from those in Example 2. Considered as a cloth.
[0094]
Using this silica abrasive grain, a polishing cloth was produced in the same manner as in Example 2, and further, a processing test of a silicon wafer was performed using the polishing cloth in the same manner. As a result, a mirror surface with a processed surface maximum height roughness Ry of 20 nm or less could be obtained in a processing time of 15 minutes. However, when the processing was continued, the processing efficiency gradually decreased, and the number of processed sheets was five. However, compared with the beginning, the machining surface roughness was the same, but the machining efficiency was reduced by about 30%, and machining after the 15th sheet became impossible.
[0095]
[Example 4]
The abrasive particles according to the present invention having the same average particle size of 30 μm and compressive fracture strength of 124.2 MPa as used in Example 2 above are finally 45% by volume, and the average particle size is 3 μm. Nickel powder (reinforcing material) was mixed with a phenol resin so that the final volume ratio was 15% by volume, and mixed and stirred with a stirrer at 60 rpm for 15 minutes to obtain a mixture. This mixture was put into a mold and subjected to a curing treatment at about 150 ° C. for about 5 hours while applying pressure to obtain a polishing grindstone.
[0096]
As a result of mounting the polishing grindstone thus obtained on an infeed grinding machine with a vertical axis and grinding a lapping finished silicon wafer, the maximum height Ry of the processed surface is 30 nm or less in a processing time of 1 minute. A mirror surface could be obtained. Further, grinding and grinding of 20 silicon wafers did not cause grinding burn, and no reduction in processing efficiency or surface roughness was observed.
[0097]
[Example 5]
A polishing grindstone was produced in the same manner as in Example 4 except that the abrasive grains according to the present invention having the same compressive fracture strength as 18.5 MPa used in Example 3 were used, and a silicon wafer grinding test was conducted. went. As a result, a mirror surface having a processed surface maximum height roughness Ry of 30 nm or less could be obtained in a processing time of 1 minute. However, when the processing was continued, grinding burn was caused on the wafer surface with 10 processed sheets. Occurred.
[0098]
【The invention's effect】
As described above, the abrasive grains of the present invention are obtained by heat-treating secondary particles formed by aggregation of a large number of primary particles at a temperature at which a neck is formed at the bonding point between the primary particles. The fine cutting edge forming particles are granular porous bodies that are partially and loosely bonded to each other, and the cutting edge forming particles grow into primary particles during the heat treatment. Therefore, at the time of use as abrasive grains, at least a portion of the processed surface that is in contact with the gap of the cutting edge forming particles functions as a cutting edge, and the cutting edge forming particles are worn. As the cutting edge is lost, it falls off, new cutting edge forming particles are sequentially projected onto the machined surface, and the bonding force between the cutting edge forming particles is optimized to maintain excellent quality. Extremely efficient and in a long time It is possible to perform stable processing I.
[0099]
In addition, the polishing tool of the present invention is a polishing tool that has high processing efficiency, enables high-quality processing, and has a long life.
In addition, the polishing apparatus of the present invention is a polishing apparatus that has high polishing efficiency and high polishing quality, and has a long tool life.
[0100]
In addition, according to the method for producing an abrasive grain of the present invention, a self-generated blade is always formed on the abrasive grain during polishing and grinding, the removal of chips is good, and excellent quality is maintained while maintaining excellent quality. It is possible to stably and reliably obtain abrasive grains capable of performing the above.
[0101]
Moreover, according to the polishing tool manufacturing method of the present invention, it is possible to obtain a long-life polishing tool capable of performing excellent efficiency while maintaining excellent quality.
Further, according to the method for producing a polishing grindstone of the present invention, it is possible to obtain a polishing grindstone that can be processed extremely efficiently while maintaining excellent quality.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of the relationship between a load and a compression displacement in a compressive fracture strength test of abrasive grains.
FIG. 2 is a scanning electron microscope (SEM) photograph of secondary particles (a diagram showing the whole).
FIG. 3 is a scanning electron microscope (SEM) photograph of secondary particles (partially enlarged (before heat treatment)).
FIG. 4 is a scanning electron microscope (SEM) photograph of the abrasive grains according to the present invention (partially enlarged (after heat treatment)).
5 is an enlarged photograph of the glass disk surface before polishing in Example 1. FIG.
6 is a chart showing the measurement results of the surface roughness of the glass disk surface before polishing in Example 1. FIG.
7 is an enlarged photograph of the glass disk surface after polishing in Example 1. FIG.
8 is a chart showing the measurement results of the surface roughness of the glass disk surface after polishing in Example 1. FIG.
9 is an enlarged photograph showing the state of abrasive grains on the polishing film surface after polishing use in Example 1. FIG.
10 is an enlarged photograph of the surface of a glass disk before polishing in Comparative Example 1. FIG.
11 is a chart showing the results of measuring the surface roughness of the glass disk surface before polishing in Comparative Example 1. FIG.
12 is an enlarged photograph of a polished glass disk surface in Comparative Example 1. FIG.
13 is a chart showing the results of measuring the surface roughness of the polished glass disk in Comparative Example 1. FIG.
14 is an enlarged photograph showing the state of abrasive grains on the polishing film surface after polishing use in Comparative Example 1. FIG.
15 is an enlarged photograph of the surface of a glass disk after polishing in Comparative Example 2. FIG.
16 is a chart showing the measurement results of the surface roughness of the polished glass disk in Comparative Example 2. FIG.
FIG. 17 is a diagram in which the relationship between the abrasive fracture compressive strength, the processed surface roughness, and the machining efficiency in a polishing film having abrasive grains having various compressive fracture strengths is examined.
FIG. 18 is a diagram in which the relationship between the specific pore surface area of abrasive grains, the roughness of the machined surface, and the machining efficiency in a polishing film having abrasive grains having various compressive fracture strengths is examined.
FIG. 19 is a diagram showing an example of a polishing apparatus for silicon processing provided with a polishing grindstone having abrasive grains according to the present invention.
[Explanation of symbols]
1 Silicon wafer
2 Polishing cloth (or polishing film)
10 Rotating part
20 Surface plate

Claims (23)

A porous material obtained by heat-treating secondary particles formed by aggregation of a large number of primary particles at a temperature at which a neck is formed at a bonding point between the primary particles, thereby growing the primary particles inside the secondary particles. Of abrasive grains,
(A) Cutting edge forming particles formed by the growth of the primary particles are loosely coupled to each other by the neck,
(B) A void is formed between the cutting edge forming particles,
(C) the neck is formed into a one-leaf hyperboloid, and
(D) the abrasive grains pore specific surface area of the porous abrasive grain is characterized <br/> that it is 18000cm ² / cm ³ or more 700000cm ² / cm ³ below. When used as abrasive grains, said cutting edge forming particles of the processed surface, at least in contact with the gap portion is configured to work as a cutting edge, a portion of cutting edge forming particles is cutting edge worn is intended to fall off according to lose, also new cutting edges formed particles the abrasive in the grains, the abrasive grains according to claim 1, characterized in that the sequentially projected on the processed surface.   The abrasive grain according to claim 1 or 2, wherein the compressive fracture strength is 1 MPa or more and 500 MPa or less.   The abrasive according to claim 3, wherein the compressive fracture strength is 20 MPa or more and 300 MPa or less. The pore specific surface area is 100,000 cm ² / Cm ³ More than 300,000cm ² / Cm ³ The abrasive grain according to any one of claims 1 to 4, wherein: The abrasive according to any one of claims 1 to 5, wherein an average particle diameter of the cutting edge forming particles is 5 µm or less. The abrasive grain according to any one of claims 1 to 6, wherein the abrasive grain does not contain a binder for bonding the cutting edge forming particles to each other. A process of aggregating a number of primary particles to obtain secondary particles;
By subjecting the secondary particles to heat treatment at a temperature at which a neck is formed at the bonding point between the primary particles, and growing the primary particles, (i) cutting edge forming particles formed by the growth of the primary particles (B) a void is formed between the cutting edge forming particles, (c) the neck is formed into a single leaf hyperboloid, and (d) the porous abrasive grains are formed. Pore specific surface area of 18000cm ² / Cm ³ More than 700000cm ² / Cm ³ A step of obtaining porous abrasive grains,
A method for producing abrasive grains, comprising: The method for producing abrasive grains according to claim 8, wherein the cutting blade-forming particles formed as described above have an average particle size of 5 μm or less. A polishing tool comprising the abrasive grain according to any one of claims 1 to 6 on a polishing surface. The polishing tool according to claim 10, wherein abrasive grains are exposed on a polishing surface of the polishing tool. The polishing tool according to claim 10 or 11, wherein the polishing tool is any one of a polishing film, a polishing cloth, and a polishing grindstone. The polishing tool according to claim 12, wherein the polishing tool is a polishing film, and a thickness of a binder layer for fixing the abrasive grains to the base film is smaller than a maximum diameter of the abrasive grains. . 14. The polishing tool according to claim 10, wherein a content ratio of the abrasive grains in a portion of the polishing tool having the abrasive grains is 5% by volume or more and 90% by volume or less. A process of aggregating a number of primary particles to obtain secondary particles;
Subjected to heat treatment at a temperature at which the neck is formed the secondary particles to the point of attachment between the primary particles, by growing the primary particles, the cutting edge formed particles formed by growth of (i) the primary particle (B) a void is formed between the cutting edge forming particles, (c) the neck is formed into a single leaf hyperboloid, and (d) the porous abrasive grains are formed. Obtaining a porous abrasive having a pore specific surface area of 18000 cm ² / cm ³ or more and 700000 cm ² / cm ³ or less;
Fixing the abrasive grains to a substrate;
A method for producing a polishing tool, comprising: 16. The method for manufacturing an abrasive tool according to claim 15, wherein in the step of fixing the abrasive grains to the base material, one or more binders selected from resin, ceramic and metal are used. The method for manufacturing an abrasive tool according to claim 15 or 16, wherein in the step of fixing the abrasive grains to the base material, the abrasive grains are fixed to the base material together with the reinforcing material. The method for producing a polishing tool according to claim 17, wherein the reinforcing material is at least one selected from metal powder, organic fiber, inorganic fiber, and metal fiber. The method for manufacturing an abrasive tool according to any one of claims 15 to 18, wherein the abrasive tool is an abrasive film or an abrasive cloth. A process of aggregating a number of primary particles to obtain secondary particles;
  By subjecting the secondary particles to heat treatment at a temperature at which a neck is formed at the bonding point between the primary particles, and growing the primary particles, (a) cutting edge forming particles formed by the growth of the primary particles (B) a void is formed between the cutting edge forming particles, (c) the neck is formed into a single leaf hyperboloid, and (d) the porous abrasive grains are formed. Pore specific surface area of 18000cm ² / Cm ³ More than 700000cm ² / Cm ³ Obtaining porous abrasive grains as described below;
  Mixing or kneading the binder for bonding the abrasive grains and the abrasive grains to obtain an abrasive mixed material;
  Forming the abrasive mixture material into a grinding wheel;
A method for producing a grinding wheel for polishing, comprising: 21. The method for producing a polishing grindstone according to claim 20, wherein a reinforcing material is added in the step of mixing or kneading the abrasive grains and a binding material for bonding the abrasive grains to obtain an abrasive grain mixed material. . The method for producing a polishing stone according to claim 21, wherein the reinforcing material is at least one selected from metal powder, organic fiber, inorganic fiber, and metal fiber. A polishing apparatus comprising the polishing tool according to any one of claims 10 to 14.

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