JP2003011062A - Polishing tool and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing tool capable of machining and forming a mirror finished surface stably and efficiently. SOLUTION: Secondary particles 12 formed by coagulating primary fine grains 11 such as colloidal silica and ultrafine zirconia and having an average grain size of above 30 μm, 300 μm or less, and preferably 40 to 100 μm are fixed on a basic material 16 by a bond 18 as abrasive to form the polishing tool 10 so that a condition in which the secondary grains protrude from a surface of the bond at all times is maintained and chips can be satisfactorily removed to machine and form the mirror finished surface stably and efficiently when performing polishing and machining.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing tool and a method for manufacturing a polishing tool, and more particularly, it is suitable for finishing hard and brittle materials such as silicon and glass, and metal materials such as steel and aluminum. The present invention relates to a polishing tool and a method for manufacturing the same.

[0002]

2. Description of the Related Art Polishing (mirror finishing) using a polishing machine is used for the final finishing of the surface of parts made of various hard and brittle materials such as silicon wafers and glass disks, and metallic materials such as steel and aluminum. Has been done. That is, for example, a so-called abrasive slurry, in which fine free abrasive grains such as diamond paste are dispersed in a solvent as an abrasive to form a paste or slurry,
Polishing the processed surface by rotating the rotary table while supplying it to the gap between the polishing cloth attached to the rotary table of the polishing machine and the processed surface of the workpiece (hereinafter referred to as "processed surface" as appropriate). Was. In this processing method, it is easy to use fine free abrasive grains as an abrasive, so it is possible to easily obtain a mirror-finished machined surface with excellent machined surface quality and to use a large amount of abrasive slurry. There is an advantage that stable processing characteristics (processing efficiency, processing surface roughness, etc.) can be maintained. Therefore, polishing work using the abrasive slurry has been performed at many work sites.

However, in the polishing process using the abrasive slurry, since a large amount of the abrasive slurry is used, there are disadvantages that the surrounding environment is contaminated and the load on the environment due to waste liquid treatment increases. To improve the machining efficiency, the polishing speed (rotational speed of the rotary table) may be increased. However, when the polishing speed exceeds a certain level, the centrifugal force reduces the amount of abrasive supplied to the processed surface, Then, the phenomenon that the processing efficiency is lowered occurs. That is, in the polishing process using the abrasive slurry, there is a limit to the improvement of processing efficiency, which is one obstacle to the improvement of productivity.

Therefore, there is a demand for a machining tool which can obtain an excellent machined surface roughness equivalent to the machined surface roughness by polishing (mirror processed surface roughness) without using an abrasive slurry. It's getting higher. In particular, so-called fixed-abrasive machining tools, in which the abrasive grains are fixed to the base material of the tool, have come to the attention.

In the polishing process using abrasive grains, in order to obtain a machined surface having a small surface roughness, it is usually advantageous to use fine abrasive grains in order to reduce the cutting depth of the abrasive grains. However, in the fixed-abrasive machining tool, if abrasive grains having a grain size of several μm or less are used in order to obtain a machined surface roughness in a mirror surface state, when the abrasive grains are used, the base material (or bonding material) of the fixed-abrasive machining tool and The frequency of contact with the surface to be machined increases, and as a result, the machining resistance rapidly increases, the abrasive grains fall off, and in the worst case, the machine becomes incapable of machining. Further, even if measures are taken to suppress the contact between the base material (or the binder) and the processed surface, the particle size of the abrasive grains is small, so that the processing efficiency decreases with time. That is, it was difficult to satisfy both the improvement of the machining efficiency and the improvement of the quality of the machined surface at the same time.

Therefore, in order to solve these problems,
A fixed-abrasive machining tool has been developed that uses an aggregate of fine abrasive grains. The purpose of this is to obtain a machined surface having a small surface roughness by the action of fine abrasive grains and to improve the machining efficiency by the aggregate of the abrasive grains (aggregated abrasive grains).

The applicant of the present application has previously proposed an invention relating to a so-called polishing film having a polishing layer on a film-shaped substrate (see Japanese Patent Laid-Open No. 2000-237962).
The present invention provides a polishing tool in which granulated particles having an average particle size in the range of 1 to 30 μm formed by aggregating primary particles of 0.5 μm or less are fixed as a polishing agent on a substrate with a binder resin ( Polishing film).

[0008]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
According to the polishing tool disclosed in Japanese Patent No. 37962, 0.5
The average particle size of granulated particles obtained by agglomerating primary particles of μm or less is 1
Since it is within the range of -30 μm, it is possible to stably obtain a good machined surface. However, further research after that revealed that the working efficiency decreased when the working was performed continuously.

The present invention has been made under the above circumstances, and a first object thereof is to provide a polishing tool capable of efficiently performing stable mirror surface processing.

A second object of the present invention is to provide a method of manufacturing a polishing tool which can efficiently perform stable mirror surface processing.

[0011]

The invention according to claim 1 has an average particle size of 3 formed by aggregating fine primary particles.
The polishing tool is characterized in that secondary particles within a range of more than 0 μm and 300 μm or less are fixed as a polishing agent on a base material with a binder.

According to this, since the average particle diameter of the secondary particles (abrasive material) exceeds 30 μm, during the polishing process, the secondary particles are always kept protruding beyond the surface of the binder, and the chips are Is also well removed, and stable mirror surface processing can be efficiently performed. In addition, when the abrasive is a single particle, the abrasive is rapidly crushed during processing, and the abrasion of the abrasive rapidly progresses, but the abrasive is an aggregate (secondary particle).
In this case, the abrasion of the polishing material gradually progresses, so that the abrasion of the polishing tool can be suppressed.

However, if the average particle size of the secondary particles exceeds 300 μm, scratches are likely to occur on the machined surface, and the quality of the machined surface is deteriorated more frequently.

In this case, as in the polishing tool according to claim 2, the secondary particles have an average particle size of 40 to 100 μm.
Can be within the range of.

In each of the polishing tools described in claims 1 and 2, as in the polishing tool described in claim 3, the average particle diameter of the primary particles can be 5 μm or less.

In each of the polishing tools described in claims 1 to 3, the content of the secondary particles with respect to the total volume of the binder and the secondary particles is the same as that of the polishing tool described in claim 4. , 5 to 90% by volume.

In each of the polishing tools described in claims 1 to 4, as in the polishing tool described in claim 5, the secondary particles are
It may be that the binder is not included therein.

In each of the polishing tools described in claims 1 to 5, as in the polishing tool described in claim 6, at least one of a metal, an inorganic material and an organic material is further fixed as an additive on the base material. Can be.

In this case, as in the polishing tool according to claim 7, the additive can contain at least one of powder and fiber.

In this case, as in the polishing tool according to the eighth aspect, the additive may contain a powder, and the average particle size of the powder may be in the range of 0.3 to 300 μm.

In the polishing tool according to claim 7, as in the polishing tool according to claim 9, the additive contains a fiber, and the fiber has a minor axis of 0.1 to 15 μm and a major axis of 0.3. ~
It may be within the range of 300 μm.

In each of the polishing tools according to claims 6 to 9, as in the polishing tool according to claim 10, the additive with respect to the total volume of the binder, the secondary particles and the additive is added. The content may be in the range of 5 to 80% by volume.

In each of the polishing tools according to any one of claims 1 to 10, as in the polishing tool according to claim 11, the binder may be at least one of resin, ceramics and metal. .

A twelfth aspect of the present invention is a method for manufacturing a polishing tool in which an abrasive is fixed on a substrate, wherein the average particle size formed by aggregating fine primary particles exceeds 30 μm. And a kneading step of kneading the abrasive material composed of secondary particles within a range of 300 μm or less and a binder to obtain a kneaded material; a coating step of applying the kneaded material onto a base material; And a solidifying step of solidifying the applied kneaded product.

According to this, first, the average particle size formed by aggregating fine primary particles exceeds 30 μm, and 30
The secondary particles in the range of 0 μm or less and the binder are kneaded to obtain a kneaded product in which the secondary particles are uniformly dispersed in the binder (kneading step). Then, the kneaded material is applied onto the base material (application step), and the kneaded material applied onto the base material is solidified (solidification step) to obtain a secondary material having a predetermined average particle size on the base material. It is possible to manufacture a polishing tool in which particles are uniformly dispersed as an abrasive.

In this case, as in the method for manufacturing a polishing tool according to a thirteenth aspect, at least one of metal, inorganic material and organic material can be further kneaded in the kneading step.

In the method for manufacturing each of the polishing tools according to claims 12 and 13, as in the method for manufacturing the polishing tool according to claim 14, fine primary particles are aggregated and averaged prior to the kneading step. Particle size exceeds 30 μm and 300 μm
A granulation step of forming secondary particles within the following range can be further included.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments and examples of the present invention will be described below.

FIG. 1A shows a sectional view of a polishing tool 10 according to an embodiment of the present invention. The polishing tool 10 includes secondary particles 12 which are aggregates of fine primary particles.
And an additive 14, a base material 16 and a binder 18. That is, the polishing layer 20 including the secondary particles 12, the additive 14, and the binder 18 is formed on the base material 16.

The secondary particles 12 are generally hard inorganic substances, although depending on the object to be processed, and as shown in the enlarged view of FIG. 1 (B), the secondary particles 12 are fine particles having an average particle size of 5 μm or less. Primary particles 11 are aggregated, exceeding 30 μm, and 300
Agglomerates with an average particle size of less than or equal to μm, preferably in the range of 40 to 100 μm are suitable. Normal secondary particles 12
As a material to be used for silica, silica (silicon oxide), ceria (cerium oxide), diamond, cBN (cubic boron nitride), alumina (aluminum oxide), silicon carbide and the like can be used, but the materials are not limited to these. is not. Although not normally used as an abrasive, it is also possible to use an aggregate (aggregated powder) used for applications such as filters and spacers. The polishing layer 20
The content of the secondary particles 12 therein is preferably in the range of 5 to 90% by volume. In addition, it is desirable that the secondary particles 12 do not include inclusions such as a binder. Therefore, for example, when using a commercially available agglomerated powder,
It is better to perform heat treatment in advance.

The secondary particles 12 are formed by, for example, a general sol-gel method in which a sol containing primary particles is hydrolyzed and the primary particles 11 are aggregated into a predetermined size. As a result, the secondary particles 12 containing no inclusions such as a binder inside
Is obtained. The shape of the secondary particles 12 may be spherical, granular or amorphous.

Further, as a method of forming the secondary particles 12,
It is not limited to the formation method utilizing precipitation by an aqueous solution reaction such as the sol-gel method, but depending on the material, the formation method utilizing precipitation from an aqueous solution (for example, spray dryer method, freeze drying method, solvent drying method). , A solid formation method (for example, thermal decomposition of solid matter, solid-phase reaction), a formation method from gas (for example, evaporation-condensation, vapor-phase decomposition method, vapor-phase reaction) and the like can be used. Moreover, you may use the impact method which makes primary particles collide with each other using a high-speed air stream. As a result, it suffices that secondary particles 12 having a predetermined average particle diameter be obtained without including inclusions such as a binder inside.

In particular, colloidal silica, fumed silica and colloidal ceria are ultrafine particles, have a chemical activity, and exhibit a mechanochemical action on the surface to be processed. Therefore, the primary particles constituting the secondary particles 12 are formed. It is a very preferable material as 11.

As the additive 14, powders or fibers of metals, inorganic substances and organic substances can be used. Suitable powders have an average particle size in the range of 0.3 to 300 μm, and fibers have an average minor axis of 0.1 to 15 μm.
m, and an average major axis within the range of 0.3 to 300 μm is suitable. As the metal powder, for example, a powder of copper or aluminum can be used, and as the powder of the inorganic substance, for example, a solid lubricant such as molybdenum disulfide or a powder of diamond, cBN, silica, alumina, silicon carbide, iron oxide or the like. As the organic substance powder, for example, a powder of acrylic resin, urethane resin, or the like can be used. Further, as the metal fiber, for example, a fiber such as copper, chromium, or nickel can be used,
Fibers such as alumina, silicon carbide, and carbon can be used as the inorganic fibers, and fibers such as acrylic resin can be used as the organic fibers. The additive 14 is not limited to one kind, and a plurality of materials may be used.

The content of the additive 14 in the polishing layer 20 is preferably in the range of 5 to 80% by volume, and the type and shape of the additive 14, the content of the secondary particles 12 and the polishing tool. The optimum content rate is determined by the mechanical properties required for No. 10. Although the polishing tool 10 of the present embodiment contains the additive 14, it may not necessarily be contained as long as the characteristics required for the polishing tool are satisfied.

Further, the secondary particles 12 and the additives 14 may be subjected to surface modification (surface treatment) such as coupling treatment (for example, silane coupling treatment or titanate coupling treatment) as an example. . As a result, the bond with the binder 18 becomes stronger and the effect as a filler can be expected. Here, depending on the types of the secondary particles 12 and the additives 14, the material of the binder 18, and the intended modification contents (for example, improvement of rigidity, improvement of impact strength, etc.), the optimum treatment type and treatment The method of is decided.

As the base material 16, a polymer film such as polyethylene terephthalate (commonly called PET) or polyimide can be usually used, but besides, a non-woven fabric, a metal foil, a strong and rigid metal, a ceramic or the like can be used.

As the binder 18, resin, ceramics and metal can be used. In the case of resin, not only thermosetting resin and thermoplastic resin but also photo-curing resin can be used.

Next, the method for manufacturing the polishing tool of the present invention will be briefly described.

First, fine primary particles are aggregated by a sol-gel method or the like to form secondary particles having an average particle diameter in the range of more than 30 μm and 300 μm or less (granulating step). Then, the secondary particles, the additive, and the binder are kneaded using a homogenizer or the like to obtain a kneaded product in which the secondary particles and the additive are uniformly dispersed in the binder (kneading step).
Next, this kneaded material is applied onto a base material using a wire bar coater, and the binder is solidified by heating the kneaded material at a predetermined temperature for a predetermined time using a thermostatic bath or the like, and secondary particles and additives are added. Fix on the substrate (solidification step). This makes it possible to manufacture a polishing tool in which secondary particles and additives are uniformly dispersed and fixed on a base material.

Further, in the above embodiment, it is desirable that the average particle size of the primary particles is 5 μm or less in the granulating step. The granulation step can be omitted when a commercially available agglomerated powder is used.

In the above embodiment, the additives are kneaded in the kneading step, but they are not always necessary.

Further, in the above-mentioned embodiment, the kneaded material is applied onto the substrate by using the wire bar coater, but the present invention is not limited to this, and a gravure coater, a reverse roll coater, a knife coater or the like may be used. Is also good. This is because it suffices that the kneaded product can be applied on the substrate with a uniform thickness.

Further, in the above embodiment, the surface modification treatment described above may be applied to the surfaces of the secondary particles and the additives prior to the kneading step.

Next, examples of the present invention will be described.

Example 1 In this example 1, ultrafine colloidal silica particles having an average particle size of 50 nm were used as primary particles, and urethane resin N2301 (manufactured by Nippon Polyurethane Industry Co., Ltd.) was used as a binder. 75μ thickness as base material
m polyethylene terephthalate film was used.
In addition, in this Example 1, the additive is not included.

The ultrafine colloidal silica particles were aggregated by the sol-gel method to obtain secondary particles of silica having an average particle size of 50 μm and containing no inclusions such as binder. That is, in Example 1, first, ultrafine colloidal silica particles and a solution containing water and alcohol were mixed at a predetermined ratio and hydrolyzed to form a gel, and the silica particles were aggregated. Then, when the aggregate of silica particles reached a desired size, the aggregate was placed in a constant temperature bath at 50 ° C. to 65 ° C. to evaporate water, organic solvent, etc. contained in the aggregate. Furthermore, the particle size distribution of the aggregate was measured using a laser diffraction / scattering type particle size distribution measuring device, and the frequency integrated value was 50%.
It was confirmed that the particle size (median size) was 50 μm. The aggregate thus formed was used as a secondary particle.

Then, the secondary particles and the urethane resin were weighed to form a mixture. Here, each amount was determined so that the secondary particles occupy 35% by volume in this mixture.

Next, the above mixture was kneaded with a stirrer so that the secondary particles were uniformly dispersed in the urethane resin to obtain a kneaded product. Here, the mixture was kneaded at room temperature at a rotation speed (for example, 50 rpm) at which secondary particles were not destroyed while stirring for about 10 minutes.

Then, using a wire bar coater, the above kneaded product is applied to a film of polyethylene terephthalate in a uniform thickness, and then, in order to accelerate the polymerization of the urethane resin, it is heated at 80 ° C. for 3 hours in a constant temperature bath. After heating for an hour, a polishing tool was obtained. The thickness of the polishing layer in this polishing tool was almost the same as the maximum particle size of the secondary particles.

The polishing tool thus prepared was attached to the surface plate of a lapping machine, and a silicon wafer having a lapping finish was processed. As a result, a mirror surface having a processed surface roughness of 10 nmRy or less was obtained in a processing time of 15 minutes. I was able to. Further, even when 50 silicon wafers were subsequently processed, the secondary particles were projected from the surface of the binder, and the reduction of the processing efficiency and the processed surface roughness was hardly recognized. In addition, the processed surface roughness is Futamari Surf S4 made by Thera Hopson
It was measured using C.

Example 2 In this example 2, ultrafine zirconia particles having an average particle size of 50 nm were used as primary particles, and urethane resin N2301 (manufactured by Nippon Polyurethane Industry Co., Ltd.) was used as a binder. A 75 μm-thick polyethylene terephthalate film was used as a substrate. In addition, in the present Example 2, the additive is not included.

Ultrafine zirconia particles were aggregated by a spray dryer method to obtain secondary particles of zirconia having an average particle diameter of 50 μm and containing no inclusions such as a binder.
That is, in Example 2, ultrafine zirconia particles were slurred with an aqueous binder (PVA, etc.) and sprayed with a spray dryer to form an aggregate having a desired size. Then, the aggregate is heated to 400 ° C. using an electric furnace.
The mixture was heated for 1 hour to evaporate the aqueous binder. Generally, in the spray dryer method, the particle size is 1 μm to 300 μm.
When aggregates up to m are obtained and the particle size distribution of the aggregates is not sharp, a classification process using a sieve may be added. Furthermore, the particle size distribution of the aggregate was measured using a laser diffraction / scattering type particle size distribution measuring device, and it was confirmed that the particle size (median size) at a frequency integrated value of 50% was 50 μm. The aggregate thus formed was used as a secondary particle. FIG. 2A is an enlarged view of the secondary particles with a scanning electron microscope, and pores formed by evaporation of the water-based binder can be seen inside. Also, FIG.
(B) is a microscope image of the appearance of secondary particles, showing a sharp particle size distribution.

Then, the secondary particles and the urethane resin were weighed to form a mixture. Here, each amount was determined so that the secondary particles occupy 35% by volume in this mixture.

Next, using a stirrer, the above mixture was kneaded so that the secondary particles were uniformly dispersed in the urethane resin to obtain a kneaded product. Here, the mixture was kneaded at room temperature at a rotation speed (for example, 50 rpm) at which secondary particles were not destroyed while stirring for about 10 minutes.

Then, using a wire bar coater, the above kneaded material was applied to a film of polyethylene terephthalate in a uniform thickness, and then, in order to accelerate the polymerization of the urethane resin, it was heated at 80 ° C. for 3 hours in a constant temperature bath. After heating for an hour, a polishing tool was obtained. The thickness of the polishing layer in this polishing tool was almost the same as the maximum particle size of the secondary particles.

The polishing tool thus prepared was attached to the surface plate of the lapping machine, and as shown in FIG.
As a result of processing a glass disk (BK7 optical glass disk) having a surface roughness of 2 μmRy, a processing surface roughness of 30 nmRy was obtained in a processing time of 3 minutes as shown in FIG.
The following mirror surface was obtained. Further, even if 30 glass discs were subsequently processed, there was almost no reduction in processing efficiency or surface roughness.

Comparative Example 1 In Comparative Example 1, ultrafine colloidal silica particles having an average particle diameter of 50 nm were used as primary particles, and urethane resin N2301 (manufactured by Nippon Polyurethane Industry Co., Ltd.) was used as a binder. 75μ thickness as base material
m polyethylene terephthalate film was used.
This is the same as in the first embodiment described above.

Ultrafine colloidal silica particles were aggregated by a sol-gel method to obtain secondary particles of silica having an average particle diameter of 20 μm and containing no inclusions such as a binder inside. The average particle size is smaller than that in Example 1 described above.

Then, the secondary particles and the urethane resin were weighed into a mixture. Here, each amount was determined so that the secondary particles occupy 35% by volume in this mixture.

Next, using a stirrer, the above mixture was kneaded with stirring so that the secondary particles were uniformly dispersed in the urethane resin to obtain a kneaded product.

Then, using a wire bar coater, the above kneaded product was applied to a film of polyethylene terephthalate in a uniform thickness, and then, in order to accelerate the polymerization of the urethane resin, it was heated at 80 ° C. for 3 hours in a constant temperature bath. After heating for an hour, a polishing tool was obtained. The thickness of the polishing layer in this polishing tool was almost the same as the maximum particle size of the secondary particles. That is, the only difference from Example 1 described above is the average particle size of the secondary particles.

The polishing tool thus prepared was attached to the surface plate of the lapping machine, and a silicon wafer having a lapping finish was processed. As a result, a mirror surface having a processed surface roughness of 10 nmRy or less was obtained in a processing time of 15 minutes. I was able to
When processing was continued, the processing efficiency gradually decreased, and when the number of processed sheets was 20, the processing surface roughness was equivalent to that at the start of processing, but the processing efficiency decreased by 30%.

Comparative Example 2 In Comparative Example 2, ultrafine zirconia particles having an average particle diameter of 50 nm were used as primary particles, and urethane resin N2301 (manufactured by Nippon Polyurethane Industry Co., Ltd.) was used as a binder. A 75 μm-thick polyethylene terephthalate film was used as a substrate. This is the same as the second embodiment described above.

Ultrafine zirconia particles were agglomerated by a spray dryer method to obtain secondary particles of zirconia having an average particle diameter of 15 μm and containing no inclusions such as a binder.
The average particle size is smaller than that in Example 2 described above.

Then, the secondary particles and the urethane resin were weighed into a mixture. Here, each amount was determined so that the secondary particles occupy 35% by volume in this mixture.

Next, using a stirrer, the above mixture was kneaded with stirring so that the secondary particles were uniformly dispersed in the urethane resin to obtain a kneaded product.

Then, using a wire bar coater, the above kneaded material is applied to a substrate, that is, a film of polyethylene terephthalate in a uniform thickness, and then a thermostatic bath is used to accelerate the polymerization of the urethane resin. It was heated at 0 ° C. for 3 hours to obtain a polishing tool. The thickness of the polishing layer in this polishing tool was almost the same as the maximum particle size of the secondary particles. That is,
The difference from Example 2 described above is only the average particle size of the secondary particles.

The polishing tool thus prepared was attached to the surface plate of a lapping machine, and a glass disk having a surface roughness of 2 μmRy (BK7 optical glass disk) was processed.
With a processing time of 10 minutes, it was possible to obtain a mirror surface with a surface roughness of 30 nmRy or less.
The polishing layer was almost worn, and it became impossible to continue the processing.

As described above, according to the polishing tool of Example 1, the average particle size produced by aggregating ultrafine silica particles having an average particle size of 50 nm as primary particles is 50 μm.
Since the secondary particles of m are dispersed and fixed on a polyethylene terephthalate film as a base material as an abrasive, it is intended to improve the processing efficiency by the secondary particles and the processed surface quality by the primary particles. You can That is,
It is possible to satisfy both the improvement of the machining efficiency and the improvement of the quality of the machined surface at the same time. If the abrasive is a single particle,
Abrasive wear rapidly progresses due to the large crushing of the abrasive during processing, but if the abrasive is aggregates (secondary particles), the abrasive wear gradually progresses, so Wear can be suppressed.

Further, according to the polishing tool of Example 1, as shown in FIG. 4 (A), the average particle size of the secondary particles was 50.
Since the average particle diameter of the secondary particles is 20 μm, the amount of secondary particles removed is large and efficient polishing can be performed as compared with the polishing tool of Comparative Example 1 in which the secondary particles have an average particle diameter of 20 μm. Furthermore, since the polishing tool of Example 1 and the polishing tool of Comparative Example 1 have the same secondary particle content, the interval between the secondary particles exposed on the surface of the base material is the above. The polishing tool of Example 1 is wider than the polishing tool of Comparative Example 1 described above. This indicates that the chips are discharged more smoothly by the polishing tool of the first embodiment. Therefore, according to the polishing tool of the first embodiment, it becomes possible to perform polishing processing having excellent processing efficiency.

In addition, according to the polishing tool of Example 2, the secondary particles having an average particle size of 50 μm, which are prepared by aggregating ultrafine zirconia particles having an average particle size of 50 nm as primary particles, are used as the polishing material. Since it is dispersed and fixed on the polyethylene terephthalate film as described above, it is possible to improve the processing efficiency by the secondary particles and the processed surface quality by the primary particles. That is, it is possible to satisfy both the improvement of the machining efficiency and the improvement of the quality of the machined surface at the same time.

For example, instead of the secondary particles, the average particle size is 5
With a polishing tool made using 0 μm zirconia single particles,
When the glass disk was polished for 3 minutes, a large number of scratches were generated as shown in FIG. 5, and the surface roughness was severely deteriorated from 2 μmRy before processing.
It became 3 μm Ry.

Further, according to the polishing tool of Example 2,
As shown in FIG. 4B, the average particle size of the secondary particles is 5
Since the average particle diameter of the secondary particles is 0 μm, the state in which the secondary particles always protrude from the surface of the binder is maintained during polishing as compared with the polishing tool of Comparative Example 2 in which the average particle diameter of the secondary particles is 15 μm. Further, the interval between the secondary particles exposed on the surface of the binder is wider in the polishing tool of Example 2 than in the polishing tool of Comparative Example 2 described above, and chips are discharged more favorably. Therefore, according to the polishing tool of the second embodiment, it is possible to perform polishing processing with excellent processing efficiency.

In each of the above examples, urethane resin N2301 (Nippon Polyurethane Industry Co., Ltd.) was used as the binder.
However, even with urethane resin N2304 (manufactured by Nippon Polyurethane Industry Co., Ltd.), almost similar results could be obtained.

Further, according to each of the above embodiments, since the secondary particles do not include inclusions such as a binder inside,
It is possible to prevent chips from adhering due to inclusions.
It becomes possible to maintain the processing ability of secondary particles. As a result, the stability of polishing can be improved.

In each of the above examples, if the average particle size of the primary particles is 5 μm or less, similarly excellent processed surface can be efficiently obtained. However, when the average particle diameter of the primary particles exceeds 5 μm, scratches are generated on the processed surface, and the quality of the processed surface deteriorates frequently.

In each of the above examples, the secondary particles also have an average particle size of more than 30 μm and 300 μm.
If it is the following, similarly excellent processed surface quality can be obtained with high processing efficiency. However, the average particle size of the secondary particles is 30
If the thickness is less than μm, the tool slides on the machined surface during machining, or the machining resistance increases sharply due to the direct contact between the bonding material and the machined surface. Tends to grow. On the other hand, when the average particle size of the secondary particles exceeds 300 μm, the frequency of scratches on the processed surface increases, and as shown in FIG. 6, the processed surface roughness tends to increase. Therefore, as shown in FIG. 6, when the average particle size of the secondary particles is in the range of 40 to 100 μm, it is possible to more reliably obtain excellent processed surface quality with high processing efficiency.

In each of the above examples, if the content of the secondary particles is within the range of 5 to 90% by volume of the polishing layer,
Similarly, it is possible to efficiently obtain excellent processed surface quality.
However, if the content of the secondary particles is less than 5% by volume of the polishing layer, the processing efficiency is remarkably lowered because the secondary particles (abrasive) are small, while if it exceeds 90% by volume, the binder Since the amount of the polishing tool is small, the rigidity of the polishing tool is reduced, and the deformation and breakage of the polishing tool are increased,
The strength for fixing the secondary particles is significantly reduced.

In each of the above examples, no additive is contained, but by adding the additive, even if the base material of the polishing tool is made of only one kind of material,
The mechanical properties of the polishing tool can be adjusted to a predetermined value,
It can have abrasion resistance and the like required as a polishing tool. Moreover, heat resistance can be improved. Also,
By including the additive, the dispersed state of the secondary particles can be further homogenized, the interval between the secondary particles exposed on the surface of the binder can be appropriately maintained, and so-called protrusion of the secondary particles can be secured.

When the shape of the additive is powder, the same effect as described above can be obtained as long as the average particle size is within the range of 0.3 to 300 μm. However, if the average particle size of the powder is less than 0.3 μm, the effect of the above-described addition is small, and if the average particle size exceeds 300 μm, the frequency of scratches on the processed surface increases.

When the shape of the additive is fiber, the average minor axis is 0.1 to 15 μm and the average major axis is 0.3 to 300 μm.
Within the range, the same effect as described above can be obtained. However, if the average minor axis of the fibers is less than 0.1 μm, the effect of the above-mentioned addition is small, and the average minor axis is 15
If it exceeds μm, the frequency of scratches on the machined surface increases. Similarly, if the average major axis is less than 0.3 μm, the effect of the above-mentioned addition is small, and if the average major axis exceeds 300 μm, scratches occur more frequently on the machined surface. In the case of fibers, even if the amount added is the same, it is possible to impart a hardness higher than that of powder to the polishing tool.

Further, the content of the additive is 5 to 8 in the polishing layer.
Within the range of 0% by volume, the same effect as described above can be obtained. However, if the content of the additive is less than 5% by volume of the polishing layer, the effect of the above-mentioned addition is small, and if it exceeds 80% by volume, the amount of the binder is small,
The rigidity of the polishing tool decreases, the frequency of deformation and breakage of the polishing tool increases, and the strength for fixing the secondary particles significantly decreases.

[0084]

As described above, according to the polishing tool of the present invention, the average particle size formed by aggregating fine primary particles exceeds 30 μm and is 300 μm or less, preferably 40 to 100 μm. Since the secondary particles within the range are dispersed and contained on the substrate as an abrasive, there is an effect that stable mirror surface processing can be efficiently performed.

Further, according to the method for manufacturing a polishing tool of the present invention, there is an effect that it is possible to manufacture a polishing tool capable of efficiently performing stable mirror finishing.

[Brief description of drawings]

FIG. 1 (A) is a cross-sectional configuration diagram of a polishing tool as one embodiment of the present invention, and FIG. 1 (B) is FIG. 1 (A).
3 is an enlarged view of secondary particles 12 in FIG.

FIG. 2 (A) is a view (drawing-substituting photo) showing a photograph obtained by observing secondary particles of zirconia formed by a spray dryer method with a scanning electron microscope, and FIG. 2 (B) is
It is a figure (drawing substitute photograph) which shows the photograph which observed the external appearance of the zirconia secondary particle formed by the spray dryer method with the optical microscope.

FIG. 3 (A) is a diagram (photograph as a substitute for a drawing) showing a microscopic observation of the surface state of a glass disk before polishing, and FIG. 3 (B) is a polishing tool of Example 2. It is a figure (drawing substitute photograph) which shows the photograph which observed the surface state of the glass disk after grind processing by a microscope.

FIG. 4 (A) is a diagram for explaining a difference between Example 1 and Comparative Example 1, and FIG. 4 (B) is a diagram for explaining a difference between Example 2 and Comparative Example 2. FIG.

FIG. 5 is a diagram (photograph as a substitute for a drawing) showing a microscopic observation of the surface state of a glass disk processed by using a polishing tool having a zirconia single particle having an average particle size of 50 μm as an abrasive.

FIG. 6 is a diagram for explaining the relationship between the average particle size of secondary particles and the processed surface roughness.

[Explanation of symbols]

10 ... Abrasive tool, 11 ... Primary particles, 12 ... Secondary particles, 14
... Additive, 16 ... Base material, 18 ... Binder.

Claims (14)

[Claims] 1. Secondary particles having an average particle size of more than 30 μm and not more than 300 μm formed by aggregating fine primary particles are fixed on a base material with a binder as an abrasive. Polishing tool characterized by. 2. The average particle diameter of the secondary particles is 40 to 100.
The polishing tool according to claim 1, wherein the polishing tool is in the range of μm. 3. The polishing tool according to claim 1, wherein the average particle diameter of the primary particles is 5 μm or less. 4. The content of the secondary particles with respect to the total volume of the binder and the secondary particles is in the range of 5 to 90% by volume. The polishing tool according to 1 above. 5. The polishing tool according to claim 1, wherein the secondary particles do not contain a binder inside. 6. The polishing tool according to claim 1, wherein at least one of a metal, an inorganic material, and an organic material is fixed as an additive on the base material. 7. The polishing tool according to claim 6, wherein the additive contains at least one of powder and fiber. 8. The polishing tool according to claim 7, wherein the additive contains a powder, and the average particle size of the powder is in the range of 0.3 to 300 μm. 9. The polishing according to claim 7, wherein the additive contains a fiber, and the minor axis of the fiber is within a range of 0.1 to 15 μm and the major axis thereof is within a range of 0.3 to 300 μm. Ingredient 10. The content of the additive with respect to the total volume of the binder, the secondary particles, and the additive is 5 to 5.
It is in the range of 80% by volume, and it is characterized in that
The polishing tool according to any one of 9 above. 11. The polishing tool according to claim 1, wherein the binder is at least one of resin, ceramics and metal. 12. A method of manufacturing an abrasive tool, wherein an abrasive is fixed on a base material, wherein an average particle diameter formed by aggregating fine primary particles is 30 μm.
a kneading step of kneading the abrasive material composed of secondary particles having a particle size of more than 300 m and not more than 300 μm and a binder to obtain a kneaded material; a coating step of applying the kneaded material onto a substrate; And a solidifying step of solidifying the kneaded product applied on a material. 13. The method of manufacturing a polishing tool according to claim 12, wherein in the kneading step, at least one of a metal, an inorganic material and an organic material is further kneaded. 14. Prior to the kneading step, fine primary particles are aggregated to have an average particle size of more than 30 μm and 300
14. The method for manufacturing a polishing tool according to claim 12, further comprising a granulation step of forming secondary particles within a range of μm or less.