JP2019115966A - Method for production of polishing agent, and the polishing agent - Google Patents

Abstract

To provide a production method for a polishing agent whose homogeneity in a thickness direction is maintained even in a thick polishing layer and whose service life is improved while maintaining excellent polishing rate and flatness accuracy.SOLUTION: There is provided a production method for a polishing agent comprising a base material, and a polishing layer laminated at the surface side of the base material and including abrasive grains, a filler and a binder. The method includes: a preparation step of preparing a composition for the polishing layer including the abrasive grain, filler and binder; a coating step of coating the above composition on the base material surface; and a heating step of heating the composition after the coating step. In the preparation step, the total content of the abrasive grain and filler in the solid content of the composition is made to be 60 vol% or more but 85 vol% or less. Besides, the heating step includes:a predrying step of drying the composition under the condition of 30 min. or more at room temperature; a heat-dehydration step of heat-dehydrating the moisture in the composition after the predrying step; and a heat-hardening step of heat-hardening the composition.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method of manufacturing an abrasive and an abrasive.

  In recent years, refinement of electronic devices such as hard disks has progressed. Glass, sapphire, or the like is used as a substrate material of such an electronic device in consideration of rigidity, impact resistance, and heat resistance that can correspond to downsizing and thinning. Generally, fixed abrasives are used for processing such substrates.

  This polishing material is required to have a polishing rate as well as a planarization accuracy with few scratches. As an abrasive which is excellent in polishing rate and planarization accuracy, for example, an abrasive having an abrasive layer in which abrasive grains and a filler are dispersed is proposed (International Publication No. 2016/203914). This conventional abrasive achieves both the excellent polishing rate and the planarization accuracy by adjusting the hardness and the amount of wear of the polishing layer with the abrasive grains and the filler.

  In addition, a long life is desired for the abrasive. In the above-mentioned conventional abrasives, the life is mainly determined by the thickness of the polishing layer because the polishing layer is worn. Therefore, in order to extend the life of the abrasive, it is conceivable to thicken the abrasive layer. In the above-mentioned conventional abrasives, the abrasive layer is produced, for example, by a printing method. By using a thick mask made of SUS in the manufacturing process, the polishing layer can be made thicker.

  However, in the polishing layer thus thickened, the homogeneity in the thickness direction is reduced, and a portion that is easily worn away in the thickness direction of the polishing layer is formed, making it difficult to obtain a desired life. Further, due to the non-uniformity in the thickness direction, for example, in-plane non-uniformity such as different wear rates at the central portion and the end portion of the polishing layer is easily generated. For this reason, a recessed part arises in the part which is easy to wear in the surface of a grinding layer, and the planarization precision of to-be-cut objects, such as a glass substrate, deteriorates. In order to suppress the deterioration of the planarization accuracy, it is necessary to frequently perform a dressing operation. When the thickness of the polishing layer is increased as described above, the planarization accuracy and the polishing efficiency are easily reduced, and it is difficult to set the thickness of the polishing layer to 1000 μm or more.

International Publication No. 2016/203914

  The present invention has been made in view of such problems. Even if the polishing layer is thickened, the uniformity in the thickness direction can be maintained, and the life can be improved while maintaining an excellent polishing rate and planarization accuracy. An object of the present invention is to provide a method of producing an abrasive and an abrasive.

  As a result of intensive studies on the nonuniformity of the polishing layer that occurs when the present inventors thickened the polishing layer, this nonuniformity is a composition for the polishing layer by heat drying when producing the polishing layer by a printing method. It was found that the abrasive grains and fillers contained in the substance are generated due to uneven distribution in the thickness direction. The present inventors have found that the uneven distribution of the abrasive grains and the filler in the thickness direction can be suppressed by prolonging the drying time of the polishing layer composition at normal temperature, and completed the present invention.

  That is, the invention made in order to solve the above-mentioned subject is a manufacturing method of an abrasives provided with a substrate and an abrasive layer laminated on the surface side of this substrate and containing an abrasive, a filler, and a binder, Preparation step for preparing a polishing layer composition comprising abrasive grains, a filler and a binder, a coating step for coating the polishing layer composition on the surface of the substrate, and polishing after the coating step And a heating step of heating the layer composition, and in the preparation step, the total content of the abrasive grains and the filler in the solid content of the polishing layer composition is 60 volume% or more and 85 volume% or less, The step is a preliminary drying step of drying the polishing layer composition under conditions of normal temperature for 30 minutes or more, a heating dehydration step of heating and dehydrating the moisture of the polishing layer composition after the preliminary drying step, and the heating dehydration step And a heating and curing step of heating and curing the polishing layer composition. That.

  The manufacturing method of the said abrasive | polishing material is a preliminary | backup which performs preliminary | backup drying more than the said minimum time at the normal temperature first in the heating process in the composition for polishing layers whose total content of the abrasive grain and filler in solid content is less than the said upper limit. It has a drying process. This preliminary drying step can prevent uneven distribution of the abrasive grains and the filler in the thickness direction of the polishing layer. In addition, by setting the total content of the abrasive grains and the filler in the solid content to the above-described lower limit or more, the polishing layer is appropriately worn. Since the abrasive grains which are clogged due to the wear are removed by eyedropping and new abrasive grains are exposed from the inside of the abrasive layer to the surface of the abrasive layer, an excellent polishing rate can be maintained. Therefore, even if the thickness of the polishing layer is increased, the uniformity in the thickness direction can be maintained by using the method for producing the polishing material, and the polishing material with improved life can be obtained while maintaining excellent polishing rate and planarization accuracy. It can be manufactured.

  In the coating step, the coating amount of the composition for a polishing layer may be adjusted so that the average thickness of the polishing layer is 1000 μm or more. The life of the abrasive can be further improved by adjusting the coating amount so that the average thickness of the abrasive layer is the lower limit or more. Further, in the method of manufacturing the abrasive, the uniformity in the thickness direction can be maintained even if the thickness of the polishing layer is increased, so that excellent polishing rate and planarization accuracy can be maintained.

  In the above preparation process, the wear amount by the Taber wear test of the polishing layer is 0.03 g or more and 0.15 g or less, and the wear amount between the maximum value and the minimum value by the Taber wear test measured every 500 μm in the thickness direction of the polishing layer It is good to adjust content of an abrasive grain and a filler so that a difference may be 0.080 g or less. By setting the wear amount of the polishing layer in the above range, the polishing rate and the planarization accuracy can be improved. In addition, by setting the difference between the maximum value and the minimum value of the wear amount measured every 500 μm in the thickness direction of the polishing layer to the upper limit or less, the uniformity in the thickness direction is further improved, so the dressing operation is frequently performed. Even if it does not do, stable polishing can be performed.

  The abrasive grains may be diamond abrasive grains. Diamond abrasives are harder than other abrasives. For this reason, by making the said abrasive grain into a diamond abrasive grain, polishing power can be improved and the polishing rate can be further improved.

  Another invention made in order to solve the above-mentioned subject is an abrasives provided with a substrate and an abrasive layer laminated on the surface side of this substrate and containing an abrasive, a filler and a binder, The total content of the abrasive grains and the filler in the layer is 85% by volume or less, the average thickness of the polishing layer is 1000 μm or more, and the wear amount in the Taber abrasion test of the polishing layer is 0.03 g to 0.15 g. The difference between the maximum value and the minimum value of the wear amount in the Taber abrasion test measured every 500 μm in the thickness direction of the polishing layer is 0.080 g or less.

  Since the said abrasives make the total content of the abrasive grain and filler in the said grinding | polishing layer more than the said lower limit and make the abrasion loss of a grinding | polishing layer into the said range, it is excellent in a grinding | polishing rate and planarization precision. Moreover, the said abrasives makes the total content of the abrasive grain and filler in the said polishing layer below the said upper limit, and the difference of the maximum value and minimum value of the abrasion loss measured every 500 micrometers of thickness directions of a polishing layer is said Since it is below the upper limit, the homogeneity of the polishing layer is high, and furthermore, since the average thickness of the polishing layer is above the lower limit, the life is long.

  Here, "normal temperature" refers to a temperature that is not particularly cooled or heated, and refers to a temperature of 5 ° C to 35 ° C, preferably a temperature of 15 ° C to 30 ° C. For “Abrasion amount in Taber abrasion test”, prepare a test piece, and rotate the above-mentioned test piece for 320 turns under the condition of wear wheel H-18 and load 4.9 N (500 gf) using a Taber abrasion tester. It is the value which carried out area conversion of the value which measured the mass difference of the specimen before and behind rotation to the mass difference of the specimen of diameter 104 mm. In addition, "the amount of wear by the Taber abrasion test measured every 500 μm in the thickness direction of the polishing layer" means that the polishing layer is shaved 500 μm, 1000 μm, 1500 μm,. It indicates the amount of wear measured by performing the above-mentioned Taber abrasion test.

  As described above, the abrasives produced by the method of producing an abrasive according to the present invention and the abrasives according to the present invention have excellent uniformity in the thickness direction of the polishing layer, and hence excellent polishing rate and flattening. The life can be improved while maintaining the accuracy.

It is a typical fragmentary plan view showing the abrasives concerning the embodiment of the present invention. It is a typical fragmentary sectional view in the AA line of FIG. It is a flowchart which shows the manufacturing method of the abrasives which concern on embodiment of this invention. It is a flowchart which shows the heating process of FIG. FIG. 3 is a schematic partial cross-sectional view showing an abrasive according to an embodiment different from FIG. 2;

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[Abrasive]
The abrasive 1 shown in FIGS. 1 and 2 includes a base 10, an abrasive layer 20 laminated on the front side of the base 10, and an adhesive layer 30 laminated on the back side of the base 10. . The abrasive 1 is used, for example, as a fixed abrasive for substrate processing.

<Base material>
The substrate 10 is a plate-like or sheet-like member for supporting the polishing layer 20.

  The main component of the substrate 10 is not particularly limited, but polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polyimide (PI), polyethylene naphthalate (PEN), aramid, aluminum, copper and the like can be mentioned. Be Among them, PET and aluminum having good adhesion to the polishing layer 20 are preferable. In addition, the surface of the substrate 10 may be subjected to a treatment such as a chemical treatment, a corona treatment, a primer treatment, or the like to improve adhesion. In addition, a "main component" means the component with most content, Preferably the component is 50 mass% or more, More preferably, the component of 90 mass% or more is said.

  Also, the substrate 10 may have flexibility or ductility. As described above, when the base material 10 has flexibility or ductility, the abrasive material 1 follows the surface shape of the workpiece, and the contact area between the polishing surface and the workpiece becomes large, so that the polishing rate is reduced. It will increase further. As a material of the base material 10 which has such flexibility, PET, PI, etc. can be mentioned, for example. Moreover, as a material of the base material 10 which has ductility, aluminum, copper, etc. can be mentioned.

  The shape and size of the substrate 10 are not particularly limited, but may be, for example, a square shape with one side of 140 mm or more and 160 mm or less or an annular shape with an outer diameter of 200 mm or more and 2022 mm or less and an inner diameter of 100 mm or more and 658 mm or less. In addition, the plurality of substrates 10 juxtaposed on a plane may be supported by a single support.

  The average thickness of the substrate 10 is not particularly limited, but can be, for example, 75 μm or more and 3 mm or less. If the average thickness of the substrate 10 is less than the lower limit, the strength and flatness of the abrasive material 1 may be insufficient. Conversely, when the average thickness of the base material 10 exceeds the upper limit, the abrasive 1 may be unnecessarily thick and handling may be difficult.

<Abrasive layer>
The polishing layer 20 includes abrasive grains 21, a filler 22 and a binder 23. The polishing layer 20 is composed of a single layer. That is, since the polishing layer 20 is not a layer in which a plurality of layers are stacked in the thickness direction, the boundaries of the layers do not exist, and the polishing layer 20 does not become discontinuous at the layer boundaries. Accordingly, the uniformity of the polishing layer 20 is enhanced.

(Abrasive)
Examples of the abrasive grains 21 include diamond abrasive grains, alumina abrasive grains, silica abrasive grains, ceria abrasive grains, silicon carbide abrasive grains and the like. Among them, diamond abrasives which are harder than other abrasives are preferable. By making the said abrasive grain 21 into a diamond abrasive grain, polishing power can be improved and a polishing rate can further be improved.

  In addition, as a diamond of a diamond abrasive grain, a single crystal or a polycrystal may be sufficient, and the diamond by which Ni coating etc. were processed may be sufficient. Among them, single crystal diamond and polycrystalline diamond are preferable. Single crystal diamond is harder and more abrasive than other diamonds. In addition, polycrystalline diamond is apt to be easily cleaved in a microcrystalline unit constituting a polycrystalline, and it is difficult for the eye to crush to progress, so that the reduction in polishing rate is small even if polishing is performed for a long time.

  The average particle size of the abrasive grains 21 is appropriately selected from the viewpoint of the polishing rate and the surface roughness of the object after polishing. The lower limit of the average particle size of the abrasive grains 21 is preferably 2 μm, more preferably 10 μm, and still more preferably 15 μm. On the other hand, the upper limit of the average particle size of the abrasive grains 21 is preferably 50 μm, more preferably 45 μm, and still more preferably 30 μm. If the average particle diameter of the abrasive grains 21 is less than the above lower limit, the polishing force of the polishing material 1 may be insufficient, and the polishing rate may be reduced. Conversely, if the average particle size of the abrasive grains 21 exceeds the above upper limit, the polishing accuracy may be reduced. Here, the "average particle size" refers to the 50% value (50% particle size, D50) of the volume-based cumulative particle size distribution curve measured by a laser diffraction method or the like.

  The lower limit of the content of the abrasive grains 21 in the polishing layer 20 is preferably 3% by volume, more preferably 4% by volume, and still more preferably 8% by volume. On the other hand, the upper limit of the content of the abrasive grains 21 is preferably 55% by volume, more preferably 45% by volume, and still more preferably 35% by volume. If the content of the abrasive grains 21 is less than the lower limit, the polishing power of the polishing layer 20 may be insufficient. Conversely, when the content of the abrasive grains 21 exceeds the upper limit, the abrasive layer 20 may not be able to hold the abrasive grains 21.

(filler)
Since the filler 22 improves the elastic modulus of the binder 23, the wear of the polishing layer 20 can be easily controlled. By controlling the wear of the polishing layer 20, it is possible to generate clogging of the abrasive grains 21 and spilling of the abrasive grains 21 at relatively close timing. As a result, the abrasive grains 21 in which the clogging has occurred are removed by eyedropping, and new abrasive grains 21 are exposed from the inside of the polishing layer 20 to the surface of the polishing layer 20, whereby the reduction in the polishing rate can be suppressed.

  Examples of the filler 22 include oxides such as alumina, silica, cerium oxide, magnesium oxide, zirconia, and titanium oxide, and composite oxides such as silica-alumina, silica-zirconia, and silica-magnesia. You may use these individually or in combination of 2 or more types as needed. Among them, alumina is preferable because high polishing power can be obtained.

  The average particle size of the filler 22 depends on the average particle size of the abrasive grains 21, but the lower limit of the average particle size of the filler 22 is preferably 0.01 μm, more preferably 2 μm. On the other hand, as an upper limit of the average particle diameter of filler 22, 20 micrometers is preferred and 15 micrometers is more preferred. If the average particle diameter of the filler 22 is less than the above lower limit, the effect of improving the modulus of elasticity of the binder 23 by the filler 22 may be insufficient. On the other hand, when the average particle diameter of the filler 22 exceeds the above upper limit, the filler 22 may inhibit the polishing force of the abrasive grains 21.

  Although the content of the filler 22 in the polishing layer 20 also depends on the content of the abrasive grains 21, the lower limit of the content of the filler 22 is preferably 15% by volume, and more preferably 30% by volume. On the other hand, the upper limit of the content of the filler 22 is preferably 75% by volume, and more preferably 60% by volume. If the content of the filler 22 is less than the above lower limit, the effect of improving the elastic modulus of the binder 23 by the filler 22 may be insufficient. Conversely, if the content of the filler 22 exceeds the above upper limit, the filler 22 may inhibit the polishing force of the abrasive grains 21.

  The lower limit of the total content of the abrasive grains 21 and the filler 22 in the polishing layer 20 is 60% by volume, more preferably 70% by volume, and still more preferably 77% by volume. On the other hand, the upper limit of the total content is 85% by volume, and 80% by volume is more preferable. The abrasive grain 21 and the filler 22 are firmly fixed by the binder as the said total content is less than the said minimum, and the abrasive layer 20 hardly wears away. For this reason, there is a possibility that the abrasive grains 21 in which the clogging has occurred can not be removed by the eye spill and the polishing rate is likely to be reduced. In contrast, when the total content exceeds the upper limit, it is difficult to suppress uneven distribution of the abrasive grains 21 and the filler 22 in the thickness direction of the polishing layer 20, and the polishing layer 20 may become uneven. .

(binder)
Although it does not specifically limit as a main component of the binder 23 of the grinding | polishing layer 20, A resin or an inorganic substance is mentioned.

  Examples of the resin include resins such as polyurethane, polyphenol, epoxy, polyester, cellulose, ethylene copolymer, polyvinyl acetal, polyacrylic, acrylic ester, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, and polyamide. Among them, polyacrylics, epoxys, polyesters and polyurethanes, which can easily ensure good adhesion to the substrate, are preferred. The resin may be at least partially crosslinked.

  Moreover, a silicate, a phosphate, a polyhydric-metal alkoxide etc. can be mentioned as said inorganic substance. Among them, silicates having high abrasive retention are preferred. Examples of such silicates include sodium silicate and potassium silicate.

  The main component of the binder 23 is preferably an inorganic substance. Thus, by making the main component of the binder 23 an inorganic substance, the retention of the abrasive grains 21 can be enhanced, and the abrasive grains 21 can be prevented from being disintegrated before being spilled out. For this reason, grinding power is further enhanced.

  The binder 23 may appropriately contain various assistants and additives such as a dispersant, a coupling agent, a surfactant, a lubricant, an antifoaming agent, and a colorant according to the purpose.

  The polishing layer 20 also has a plurality of convex portions 25 divided by the grooves 24 on the surface thereof. The grooves 24 are disposed on the surface of the polishing layer 20 in the form of a lattice at equal intervals. That is, the shape of the plurality of convex portions 25 is a block pattern which is regularly arranged. Further, the bottom surface of the groove 24 that divides the convex portion 25 is formed on the surface of the base material 10.

  The lower limit of the average width of the grooves 24 is preferably 0.3 mm, more preferably 0.5 mm. On the other hand, the upper limit of the average width of the grooves 24 is preferably 10 mm, more preferably 8 mm. If the average width of the grooves 24 is less than the above lower limit, abrasive powder generated by polishing may be clogged in the grooves 24. On the other hand, if the average width of the grooves 24 exceeds the above upper limit, the workpiece tends to fall into the grooves 24 at the time of polishing, so that the workpiece may be damaged.

As a lower limit of the average area of convex part 25, 1 mm ² is preferable and 2 mm ² is more preferable. On the other hand, as a maximum of the average area of convex part 25, 150 mm ² is preferred and 130 mm ² is more preferred. There is a possibility that convex part 25 exfoliates from substrate 10 as the average area of convex part 25 is less than the above-mentioned minimum. On the other hand, when the average area of the convex portions 25 exceeds the above upper limit, the contact area of the polishing layer 20 to the workpiece at the time of polishing becomes large, and the polishing rate may be reduced due to frictional resistance.

  The lower limit of the area occupancy of the plurality of convex portions 25 with respect to the entire polishing layer 20 is preferably 5%, and more preferably 10%. On the other hand, as an upper limit of the area occupancy of the said convex-shaped part 25, 60% is preferable and 55% is more preferable. When the area occupancy rate of the convex portion 25 is less than the lower limit, the pressure applied at the time of polishing is concentrated on the narrow convex portion 25 too much, and the convex portion 25 may be peeled off from the base material 10. On the other hand, if the area occupancy rate of the convex portion 25 exceeds the upper limit, the contact area of the polishing layer 20 to the workpiece at the time of polishing becomes large, and the polishing rate may be reduced due to frictional resistance. In addition, "the area of the whole grinding | polishing layer" is a concept also including the area of the groove | channel, when a grinding | polishing layer has a groove | channel.

  The lower limit of the average thickness of the polishing layer 20 (average thickness of only the convex portions 25) is 1000 μm, more preferably 1500 μm, and still more preferably 2000 μm. On the other hand, the upper limit of the average thickness of the polishing layer 20 is preferably 4000 μm, more preferably 3500 μm, and still more preferably 3200 μm. If the average thickness of the polishing layer 20 is less than the above lower limit, the durability of the polishing layer 20 may be insufficient, and the life of the polishing material 1 may be shortened. Conversely, when the average thickness of the polishing layer 20 exceeds the above upper limit, the load applied to the interface between the polishing layer 20 and the substrate 10 due to the moment generated at the time of polishing may cause the polishing layer 20 to fall easily, The manufacturing cost of 1 may increase.

  The lower limit of the wear amount of the polishing layer 20 by the Taber abrasion test is 0.03 g, and more preferably 0.06 g. On the other hand, the upper limit of the amount of wear is 0.15 g, and more preferably 0.12 g. If the amount of wear is less than the above-mentioned lower limit, the abrasive grains 21 in which the clogging has occurred can not be removed by the eye spill, and there is a possibility that the polishing rate tends to be reduced. Conversely, if the amount of wear exceeds the upper limit, the wear of the polishing layer 20 may be too fast, and the life of the polishing material 1 may be shortened.

  The upper limit of the difference between the maximum value and the minimum value of the wear amount in the Taber wear test measured every 500 μm in the thickness direction of the polishing layer 20 is 0.080 g, and 0.060 g is more preferable. When the wear amount difference exceeds the above upper limit, it means that there is a nonuniform portion in the polishing layer 20, and a recess is formed in a portion which is easily worn in the surface of the polishing layer 20 of the polishing material 1 at the time of polishing, There is a possibility that the planarization accuracy of the workpiece may deteriorate. On the other hand, the lower limit of the wear amount difference is not particularly limited, and may be 0 g. However, the wear amount difference is usually 0.001 g or more.

<Adhesive layer>
The adhesive layer 30 is a layer for supporting the abrasive 1 and fixing the abrasive 1 to a support for mounting the abrasive 1 on a polishing apparatus.

  The adhesive used for the adhesive layer 30 is not particularly limited, and examples thereof include reactive adhesives, instant adhesives, hot melt adhesives, and adhesives that can be replaced.

  As an adhesive used for this adhesive layer 30, an adhesive is preferable. By using a pressure-sensitive adhesive as the adhesive used for the adhesive layer 30, the abrasive 1 can be peeled off and replaced from the support, and reuse of the abrasive 1 and the support becomes easy. Such an adhesive is not particularly limited. For example, acrylic adhesive, acrylic-rubber adhesive, natural rubber adhesive, synthetic rubber adhesive such as butyl rubber, silicone adhesive, polyurethane adhesive Agents and the like.

  As a lower limit of the average thickness of adhesion layer 30, 0.05 mm is preferred and 0.1 mm is more preferred. On the other hand, as an upper limit of the average thickness of adhesion layer 30, 0.3 mm is preferred and 0.2 mm is more preferred. If the average thickness of the adhesive layer 30 is less than the above lower limit, the adhesive strength may be insufficient, and the abrasive 1 may be peeled off from the support. Conversely, if the average thickness of the adhesive layer 30 exceeds the above upper limit, there is a possibility that the workability may be deteriorated, for example, when the abrasive material 1 is cut into a desired shape due to the thickness of the adhesive layer 30 .

<Advantage>
In the polishing material 1, the total content of the abrasive grains 21 and the filler 22 in the polishing layer 20 is 60 volume% or more, and the wear amount of the polishing layer 20 is 0.03 g or more and 0.15 g or less. Excellent in planarization accuracy. Moreover, the said abrasives 1 make the total content of the abrasive grain 21 and the filler 22 in the polishing layer 20 85 volume% or less, and the maximum value and minimum value of the abrasion loss measured every 500 micrometers of thickness directions of the polishing layer 20 Therefore, the uniformity of the polishing layer 20 is high and the average thickness of the polishing layer 20 is 1000 μm or more, so the life is long.

[Method of producing abrasives]
The method for producing an abrasive shown in FIG. 3 mainly includes a preparation step S1, a coating step S2, a heating step S3, and an adhesive layer sticking step S4. By using the manufacturing method of the said abrasives, it is laminated on the surface side of this base material 10 shown, for example in Drawing 1 and Drawing 2, and this base material 10, and polish layer 20 which contains abrasive grain 21, filler 22, and binder 23. Abrasive material 1 can be manufactured.

<Adjustment process>
In adjustment process S1, the composition for abrasive layers containing the abrasive grain 21, the filler 22, and the binder 23 is prepared. Specifically, a composition for an abrasive layer containing materials for forming the abrasive grains 21, the filler 22, and the binder 23 is prepared as a coating liquid. In addition, in the adjustment step S1, the total content of the abrasive grains 21 and the filler 22 in the solid content of the composition for a polishing layer is set to 60% by volume or more and 85% by volume or less. The content of the abrasive grains 21 and the filler 22 in the solid content is the content of the abrasive grains 21 and the filler 22 of the polishing layer 20 after production.

  Moreover, in the manufacturing method of the said abrasives, it is preferable not to add a diluent to a coating liquid. By thus not adding the diluent to the coating liquid, a constant viscosity can be ensured, and therefore, it is possible to prevent the abrasive particles 21 and the filler 22 having a large mass from being easily accumulated at the bottom when the polishing layer 20 is applied. . Therefore, the uniformity of the polishing layer 20 is improved.

  In addition, the difference between the wear amount of the polishing layer 20 by the Taber wear test and the difference between the maximum value and the minimum value of the wear amount by the Taber wear test measured every 500 μm in the thickness direction of the polishing layer 20 Control can be performed by adjusting the content of the particles 21 and the filler 22. Therefore, in the preparation step S1, the contents of the abrasive grains 21 and the filler 22 may be adjusted so that the wear amount and the wear amount difference fall within the desired adjustment range.

  As a lower limit of the adjustment range of the said abrasion loss in preparation process S1, 0.03 g is preferable and 0.06 g is more preferable. On the other hand, as an upper limit of the adjustment range of the said abrasion loss, 0.15 g is preferable and 0.12 g is more preferable. By setting the wear amount of the polishing layer 20 within the above range, the polishing rate and the planarization accuracy can be improved.

  As an upper limit of the adjustment range of the said abrasion loss difference in preparation process S1, 0.080g is preferable and 0.060g is more preferable. By setting the difference between the maximum value and the minimum value of the wear amount measured every 500 μm in the thickness direction of the polishing layer 20 below the above upper limit, the uniformity in the thickness direction is further improved, so the dressing operation is performed frequently. Even if it does not, stable polishing can be performed. On the other hand, the lower limit of the adjustment range of the wear amount difference is not particularly limited, and may be 0 g, but the wear amount difference is usually 0.001 g or more.

<Coating process>
In the coating step S2, the composition for a polishing layer is coated on the surface of the substrate 10. Specifically, using the coating liquid prepared in the preparation step S1, the polishing layer 20 constituted of a plurality of convex portions 25 divided by the grooves 24 by the printing method is formed on the surface of the base material 10. In order to form the groove 24, a mask having a shape corresponding to the shape of the groove 24 is prepared, and the coating liquid is printed through the mask. As this printing method, for example, screen printing, metal mask printing, etc. can be used.

  As the mask for printing, a mask made of SUS is preferable. Since the mask made of SUS can be thickened, the polishing layer 20 having a large average thickness can be easily manufactured.

  The thickness of the polishing layer 20 can be mainly adjusted by the coating amount. Therefore, in the coating step S2, the coating amount of the composition for a polishing layer may be adjusted so that the average thickness of the polishing layer 20 is 1000 μm or more, more preferably 1500 μm or more, and still more preferably 2000 μm or more. By adjusting the coating amount so that the average thickness of the polishing layer 20 is equal to or more than the above lower limit, the life of the polishing material 1 can be further improved. Further, in the method of manufacturing the abrasive, even if the polishing layer 20 is thickened, the uniformity in the thickness direction is maintained, so that excellent polishing rate and planarization accuracy can be maintained. On the other hand, the upper limit of the average thickness of the polishing layer 20 adjusted in the coating step S2 is not particularly limited, but from the viewpoint of production cost, 4000 μm is preferable, 3500 μm is more preferable, and 3200 μm is more preferable.

<Heating process>
Heating process S3 heats the composition for abrasive layers after coating process S2. As shown in FIG. 4, the heating step S3 has a preliminary drying step S31, a heating and dewatering step S32, and a heating and curing step S33.

(Pre-drying step)
In the preliminary drying step S31, the composition for the polishing layer is dried at normal temperature, that is, at a temperature that does not particularly cool or heat. By performing predrying for an appropriate time in the predrying step S31, the present inventors ensure uniform dispersion of the abrasive grains 21 and the filler 22 in the polishing layer composition, and then heating is performed. However, it is known that the uniformity of the polishing layer 20 can be ensured.

  The drying temperature of the preliminary drying step S31 is not particularly limited as long as it is normal temperature, but the lower limit of the drying temperature of the preliminary drying step S31 is 5 ° C., and 15 ° C. is more preferable. On the other hand, the upper limit of the tube pushing temperature in the preliminary drying step S31 is 35 ° C., and 30 ° C. is more preferable. If the drying temperature in the preliminary drying step S31 is less than the above lower limit, the composition for polishing layer may not be sufficiently dried, and the uniformity of the polishing layer 20 may be degraded. Conversely, if the drying temperature in the preliminary drying step S31 exceeds the above upper limit, the abrasive grains 21 and the filler 22 are likely to be unevenly distributed in the polishing layer composition due to heat convection, etc. It may decrease.

  The lower limit of the drying time of the preliminary drying step S31 is 30 minutes, more preferably 60 minutes, and still more preferably 90 minutes. On the other hand, the upper limit of the drying time in the preliminary drying step S31 is not particularly limited, but 200 minutes is preferable, and 150 minutes is more preferable. If the drying time in the preliminary drying step S31 is less than the above lower limit, the composition for polishing layer may not be sufficiently dried, and the uniformity of the polishing layer 20 may be degraded. Conversely, if the drying time of the preliminary drying step S31 exceeds the above-mentioned upper limit, the production efficiency may be reduced.

(Heating dehydration process)
The heating and dewatering step S32 heats and dehydrates the moisture of the polishing layer composition after the preliminary drying step S31. By removing the moisture from the composition for polishing layer in the heat dehydration step S32, the polishing layer 20 can be cured while maintaining the homogeneity of the polishing layer 20 in the subsequent heating and curing step S33.

  As a minimum of heating temperature of heat dehydration process S32, 70 ° C is preferred and 75 ° C is more preferred. On the other hand, as a maximum of heating temperature of heat dehydration process S32, 90 ° C is preferred and 85 ° C is more preferred. If the heating temperature in the heating and dewatering step S32 is less than the above lower limit, dehydration from the polishing layer composition may be insufficient, and the uniformity of the polishing layer 20 may be degraded. On the contrary, when the heating temperature of the heating and dewatering step S32 exceeds the above upper limit, the abrasive grains 21 and the filler 22 are easily unevenly distributed in the composition for polishing layer due to heat convection etc. It may decrease.

  As a minimum of heating time of heat dehydration process S32, 30 minutes are preferred and 60 minutes are more preferred. If the heating time of the heating and dewatering step S32 is less than the above lower limit, dehydration from the polishing layer composition may be insufficient, and the uniformity of the polishing layer 20 may be degraded. On the other hand, the upper limit of the heating time of the heating and dewatering step S32 is not particularly limited, but from the viewpoint of production efficiency, the heating time of the heating and dewatering step S32 is usually 2 hours or less.

(Heating and curing process)
The heating and curing step S33 heats and cures the polishing layer composition after the heating and dewatering step S32. By this heat curing, the polishing layer 20 is formed.

  As a minimum of heating temperature of heat hardening process S33, 120 ° C is preferred and 140 ° C is more preferred. On the other hand, as an upper limit of heating temperature of heat hardening process S33, 300 ° C is preferred and 200 ° C is more preferred. If the heating temperature in the heating and curing step S33 is less than the above lower limit, the composition for polishing layer may not be sufficiently cured, the amount of wear may be increased, and the life of the abrasive 1 may be shortened. Conversely, if the heating temperature of the heat curing step S33 exceeds the above upper limit, the polishing layer 20 may be degraded by heat.

  As a minimum of heating time of heat hardening process S33, 2 hours are preferred and 2.5 hours are more preferred. On the other hand, as a maximum of heating time of heat hardening process S33, 4 hours are preferred and 3.5 hours are more preferred. If the heating time of the heating and curing step S33 is less than the above lower limit, the composition for polishing layer may not be sufficiently cured, the amount of wear may be increased, and the life of the abrasive 1 may be shortened. Conversely, if the heating time of the heating and curing step S33 exceeds the above-mentioned upper limit, the production efficiency may be reduced.

<Adhesive layer sticking process>
In adhesion layer sticking process S4, adhesion layer 30 is laminated on the back side of substrate 10. Specifically, for example, a tape-shaped adhesive layer 30 formed in advance is attached to the back surface of the substrate 10.

<Advantage>
The method for producing the abrasive material is a polishing layer composition having a total content of 85% by volume or less of the abrasive grains 21 and the filler 22 in the solid content, in the heating step S3 first under conditions of normal temperature for 30 minutes or more. It has preliminary drying step S31 which performs preliminary drying. This preliminary drying step S31 can prevent uneven distribution of the abrasive grains 21 and the filler 22 in the thickness direction of the polishing layer 20. Further, by setting the total content of the abrasive grains 21 and the filler 22 in the solid content to 65% by volume or more, the polishing layer 20 is appropriately worn. The abrasive grains 21 which are clogged due to the wear are removed by eyedropping, and new abrasive grains 21 are exposed from the inside of the polishing layer 20 to the surface of the polishing layer 20, so that an excellent polishing rate can be maintained. Therefore, even if the thickness of the polishing layer 20 is increased, the uniformity of the thickness direction is maintained by using the method for producing the abrasive, and the abrasive having the improved life while maintaining the excellent polishing rate and the planarization accuracy. Can be manufactured.

Other Embodiments
The present invention is not limited to the above embodiment, and can be implemented in various modifications and improvements in addition to the above embodiment.

  In the above embodiment, the grooves are formed in the form of a lattice at equal intervals, but the spacing and planar shape of the lattice are not limited to the above embodiment. In the above embodiment, although the bottom of the groove is the surface of the base, the depth of the groove may be smaller than the average thickness of the polishing layer, and the groove may not reach the surface of the base.

  The planar shape of the groove is not limited to a lattice, and may be, for example, a shape in which a polygon other than a quadrilateral is repeated, a circular shape, a shape having a plurality of parallel lines, or the like. Further, the planar shape of the groove may be a stripe shape provided in only one direction.

  Further, the polishing layer may have a structure without grooves.

  Although the case where the abrasives shown in FIG.1 and FIG.2 were manufactured using the manufacturing method of the said abrasives was demonstrated in the said embodiment, the abrasives which can be manufactured using the manufacturing method of the said abrasives are FIG. And it is not limited to the abrasives shown in FIG. 2, For example, the abrasives etc. whose average thickness of an abrasive layer is less than 1000 micrometers can also be manufactured.

  Although the above-mentioned embodiment explained the case where an abrasives has an adhesion layer, an adhesion layer is not an essential component and can be omitted. When the abrasive does not have the adhesive layer, the adhesive layer attaching step of the method of manufacturing the abrasive is omitted.

  Alternatively, as shown in FIG. 5, the abrasive 2 may be provided with a support 40 laminated via the adhesive layer 30 on the back surface side and a second adhesive layer 31 laminated on the back surface side of the support 40. . When the abrasive 2 includes the support 40, the abrasive 2 can be easily handled.

  Examples of the main component of the support 40 include thermoplastic resins such as polypropylene, polyethylene, polytetrafluoroethylene and polyvinyl chloride, and engineering plastics such as polycarbonate, polyamide and polyethylene terephthalate. By using such a material as the main component of the support 40, the support 40 has flexibility, and the abrasive 2 follows the surface shape of the object to be cut, and the abrading surface and the object to be cut The polishing rate is further improved because the

  The average thickness of the support 40 can be, for example, 0.5 mm or more and 3 mm or less. If the average thickness of the support 40 is less than the lower limit, the strength of the abrasive 2 may be insufficient. On the other hand, when the average thickness of the support 40 exceeds the upper limit, the support 40 may not be easily attached to the polishing apparatus, and the flexibility of the support 40 may be insufficient.

  The same adhesive as the adhesive layer 30 can be used for the second adhesive layer 31. Further, the second adhesive layer 31 can have the same average thickness as the adhesive layer 30.

  Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
Diamond abrasive grains ("LS605FN" from Lands Co., Ltd.) were prepared, and the average particle size was measured using "Microtrac MT3300 EXII" from Nikkiso Co., Ltd. The average particle size of this diamond abrasive was 7.5 μm. In addition, the kind of diamond of this abrasive grain is a 55 mass% nickel-coated treated diamond.

The above diamond abrasive grains, alumina as a filler (Al ₂ O ₃ , “LA 1200” from Pacific Random Co., Ltd., average particle diameter 12 μm), and sodium silicate as a binder (“No. 3 sodium silicate of Fuji Chemical Co., Ltd.” The mixture was adjusted so that the content of the diamond abrasive in the solid content was 5% by volume and the content of the filler was 72.7% by volume, to obtain a coating liquid.

  An aluminum plate having an average thickness of 300 μm was prepared as a substrate, and the coating solution was used to coat the surface of the substrate by printing. As a printing pattern, a mask corresponding to the grooves was used so that a polishing layer having lattice-like grooves was formed. A specific shape of the polishing layer is a block pattern in which square convex portions having a side of 3 mm are regularly arranged in a plan view, and the area occupancy rate of the plurality of convex portions to the entire polishing layer is It is 36%. The mask was made of SUS, and the coating amount was adjusted so that the average thickness of the polishing layer was 3000 μm.

  The coating liquid is subjected to preliminary drying for 120 minutes at room temperature (25 ° C.), followed by heat dehydration for 1 hour or more at 80 ° C., and heat curing for 2 hours to 4 hours at 150 ° C. in this order. The

  In addition, a hard vinyl chloride resin plate having an average thickness of 1 mm is used as a support for supporting the substrate and fixing it to the polishing apparatus, between the back surface of the substrate and the front surface of the support, and the back surface of the support A pressure-sensitive adhesive having an average thickness of 130 μm was attached to a surface plate of a polishing machine described later. A double-sided tape ("# 5605 HGD" from Sekisui Chemical Co., Ltd.) was used as the pressure-sensitive adhesive.

  Thus, the abrasive of Example 1 was obtained.

Example 2
What mixed the alumina ("DAM-03" of Denka Co., Ltd.) with an average particle diameter of 3.7 μm in a volume ratio of 1: 1 to the alumina having an average particle diameter of 12 μm as in Example 1 as a filler Example 1 and Example 1 except that a coating liquid was used which was adjusted so that the content of the diamond abrasive in the solid content was 5% by volume and the total content of the two kinds of fillers was 72.7% by volume. The abrasive of Example 2 was obtained in the same manner.

[Example 3]
An abrasive of Example 3 was obtained in the same manner as Example 2, except that the preliminary drying conditions of the coating liquid were changed to 60 minutes at room temperature (25 ° C.).

Example 4
The content of the diamond abrasives in the solid content was adjusted to 5% by volume and the content of the filler was 71% by volume, and the coating liquid was obtained in the same manner as in Example 1 except that the coating liquid was obtained. An abrasive was obtained.

Comparative Example 1
An abrasive of Comparative Example 1 was obtained in the same manner as in Example 1 except that the preliminary drying conditions of the coating liquid were changed to 15 minutes at room temperature (25 ° C.).

Comparative Example 2
A comparative example was prepared in the same manner as in Example 1 except that the content of the diamond abrasive in the solid content was adjusted to 15% by volume and the content of the filler was 74.8% by volume, and the coating liquid was obtained. 2 abrasives were obtained.

Comparative Example 3
The content of the diamond abrasives in the solid content was adjusted to 5% by volume and the content of the filler was 50% by volume, and the coating liquid was obtained in the same manner as in Example 1 except that the coating liquid was obtained. An abrasive was obtained.

[Reference Example 1]
An abrasive of Reference Example 1 was obtained in the same manner as Example 1, except that the coating amount was adjusted so that the average thickness of the abrasive layer was 1,000 μm.

[Polishing conditions]
The glass substrates were polished using the abrasives obtained in Examples 1 to 4 and Comparative Examples 1 to 3 and Reference Example 1. Three soda lime glasses having a diameter of 6.25 cm and a specific gravity of 2.4 were used as the glass substrate. A publicly known double-sided polisher was used for the above-mentioned polish. The carrier of the double-side polisher is epoxy glass with a thickness of 0.4 mm. The polishing was carried out 5 times of polishing for 15 minutes under the conditions of a polishing pressure of 150 g / cm ² , an upper platen rotational speed 60 rpm, a lower platen rotational speed 90 rpm and a SUN gear rotational speed 10 rpm. At that time, 120 cc / min of “LAP-P-32” manufactured by Palace Chemical Co., Ltd. was supplied as a coolant.

[Evaluation method]
With respect to the abrasives of Examples 1 to 4 and Comparative Examples 1 to 3 and Reference Example 1, the maximum amount of wear of the abrasive layer by the Taber abrasion test and the amount of abrasion by the Taber abrasion test measured every 500 μm in the thickness direction of the abrasive layer The difference between the value and the minimum value, the wear rate of the polishing layer per 100 μm of substrate polishing, and the flatness of the polishing layer after polishing were measured. Each measurement was performed by the following method.

<Abrasion amount>
The wear amount of the abrasive layer in the Taber abrasion test was determined by the following measurement method. First, a test piece with a diameter of 104 mm was cut out from each abrasive. Using a Taber abrasion tester ("MODEL 174" manufactured by Taber Instrument Co., Ltd.), the test piece was worn at 320 rotations under the conditions of wear wheel H-18 and a load of 4.9 N (500 gf). The mass difference [g] of the test piece before and after abrasion was measured, and it was set as the amount of abrasion. The results are shown in the "wear amount" column of Table 1.

<Abrasion amount difference>
The difference between the maximum value and the minimum value of the wear amount in the Taber wear test measured every 500 μm in the thickness direction of the polishing layer was determined by the following measurement method. With respect to the test piece for which the amount of abrasion was measured, the abrasive layer was cut by 500 μm each using a # 80 sandpaper, and the amount of abrasion was measured by the above-described Taber abrasion test. Specifically, in Examples 1 to 4 and Comparative Examples 1 to 3 in which the average thickness of the polishing layer is 3000 μm, the average thickness is 2500 μm, 2000 μm, 1500 μm, 1000 μm, 500 μm, and the average thickness of the polishing layer The amount of wear was measured at a position where the average thickness is 500 μm in Reference Example 1 in which the thickness is 1000 μm. For each abrasive, the difference between the maximum value and the minimum value among the wear amounts obtained by adding the above-described wear amount measured on the surface of the polishing layer to the measurement results was determined as the wear amount difference [g]. The results are shown in the "wear amount difference" column of Table 1.

<Wear rate>
As the wear rate of the polishing layer, the amount of decrease in thickness of the polishing layer when the substrate was polished by 100 μm was determined by the following procedure.

Every time the glass substrate is polished, the change in substrate mass [g] before and after polishing is measured, and the amount of change is calculated using the surface area of the glass substrate [cm ² ] and the specific gravity of the glass substrate [g / cm ³ ]. The polishing amount [μm] of the glass substrate before and after polishing was determined.

  The amount of decrease in thickness [μm] of the thickness of the polishing layer for each polishing of the glass substrate is the height of the polishing layer before and after polishing using an ultra-high-speed inline profile measuring instrument (“LJ-V702” from Keyence Corporation) It asked by measuring.

  The reduction amount of the thickness of the polishing layer at the time of polishing the substrate by 100 μm is calculated by dividing the reduction amount of the thickness of the polishing layer for each polishing by the polishing amount of the glass substrate and calculating 100 times. The average value for polishing was taken as the wear rate.

  Furthermore, in Examples 1 to 4 and Comparative Examples 1 to 3 in which the average thickness of the polishing layer is 3000 μm, the wear rate is as described above at positions where the average thickness is 3000 μm, 2500 μm, 2000 μm, 1500 μm, 1000 μm, 500 μm Polishing was carried out under the following polishing conditions, and the average value was taken as the wear rate. The results are shown in the "wear rate" column of Table 1. The higher the wear rate, the shorter the life of the polishing layer. The average thickness of the polishing layer was adjusted by scraping the polishing layer using # 80 sandpaper as in the measurement of the difference in the amount of wear. In addition, about the reference example 1 whose average thickness of a grinding | polishing layer is 1000 micrometers, it has not measured.

<Flatness>
In the measurement of the flatness of the polishing layer after polishing, in Examples 1 to 4 in which the average thickness of the polishing layer is 3000 μm, the average thickness is 1500 μm, that is, the thickness of the polishing layer is the central value. After the abrasive layer was scraped using # 80 sandpaper, it was calculated for the abrasive that was polished under the conditions described above. The calculation procedure is as follows.

  Place a glass substrate directly on the lower surface plate side of Myglonite stone surface plate, and place a flatness gauge (made by Chemet Japan Co., Ltd.) so that the left and right ends and the needle of the dial gauge straddle three points. , Zeroed the dial gauge.

  Next, a glass substrate was placed on the lower polishing plate side abrasive after polishing so as to be in the same position as when the zero point adjustment was performed, and a flatness gauge was placed thereon. The value of the flatness gauge at this time was read, and the "flatness in the X direction [μm]" was determined. The glass substrate at the time of measurement in the X direction was rotated by 90 degrees, and measurement was performed in the same manner. The value of the flatness gauge at this time was taken as "flatness in the Y direction [μm]". The average value of the flatness in the X direction and the flatness in the Y direction was taken as the flatness [μm] of the polishing layer. The results are shown in the "flatness" column of Table 1. In addition, in flatness, a negative numerical value means that it is concave shape, and a positive numerical value means that it is convex shape. Moreover, about the reference example 1 whose average thickness of a grinding | polishing layer is 1000 micrometers, it has not measured.

  In Table 1, "-" of Comparative Example 3 means that the polishing rate could not be measured because the polishing rate was extremely low and the glass substrate was hardly polished.

  From the results of Table 1, when the abrasives of Examples 1 to 4 are compared with the abrasives of Comparative Examples 1 and 2, the abrasives of Examples 1 to 4 are the wear amounts measured every 500 μm in the thickness direction of the abrasive layer Since the difference between the maximum value and the minimum value of is small and the flatness of the polishing layer after polishing is excellent, it can be seen that the planarization accuracy in polishing a glass substrate is excellent. Moreover, since the abrasive material of Examples 1-4 has a small abrasion rate of an abrasive layer, it turns out that lifetime is long. Furthermore, when the abrasives of Examples 1 to 4 are compared with the abrasive of Comparative Example 3, the abrasives of Examples 1 to 4 are excellent in the polishing rate.

  On the other hand, in the abrasive of Comparative Example 1, since the drying time at normal temperature is short, the difference between the maximum value and the minimum value of the wear amount measured every 500 μm in the thickness direction of the polishing layer is large, and the thickness of the polishing layer is large. It can be seen that it is uneven in the longitudinal direction. Thus, the abrasive of Comparative Example 1 is considered to be inferior in wear rate and flatness.

  In the abrasive of Comparative Example 2, the total content of the abrasive grains and the filler exceeds 85% by volume, so the amount of abrasion of the abrasive layer is large, and the maximum value of the amount of abrasion measured every 500 μm in the thickness direction of the abrasive layer The difference between the and the minimum value is also large. Thus, the abrasive of Comparative Example 2 is considered to be inferior in wear rate and flatness.

  In the abrasive of Comparative Example 3, the total content of the abrasive grains and the filler is less than 60% by volume, so the amount of abrasion of the abrasive layer is small. As a result, in the case of the abrasive of Comparative Example 3, it is considered that the abrasive grains in which the clogging has occurred can not be removed due to the eye drop and the polishing rate is lowered.

  Also, when the abrasives of Examples 1 to 4 with an average thickness of the abrasive layer of 3000 μm are compared with the abrasives of Reference Example 1 with an average thickness of the abrasive layer of 1000 μm, they are measured every 500 μm in the thickness direction of the abrasive layer. The difference between the maximum value and the minimum value of the amount of wear is equal. That is, it can be seen that the polishing layers of the abrasives of Examples 1 to 4 are relatively uniform in the thickness direction even if the average thickness of the polishing layer is large.

  From the above, a preliminary preparation is performed in which the total content of the abrasive grains and the filler in the solid content of the composition for polishing layer is 60 volume% or more and 85 volume% or less, and the composition for polishing layer is dried under conditions of 30 minutes or more at normal temperature. By the manufacturing method having the drying step, it is understood that even when the polishing layer is thickened, the uniformity in the thickness direction can be maintained, and an abrasive that can improve the life can be manufactured while maintaining excellent polishing rate and planarization accuracy.

  Further, looking at Examples 1 to 4 in detail, the abrasives of Examples 1 to 3 are superior to the abrasive of Example 4 in wear rate and planarization. From this, the difference between the maximum value and the minimum value of the wear amount in the Taber abrasion test measured every 0.03 g to 0.15 g of the abrasion amount in the Taber abrasion test of the polishing layer every 500 μm in the thickness direction of the abrasive layer By adjusting content of an abrasive grain and a filler so that it may be 0.080 g or less, it turns out that the planarization precision of glass substrate grinding and the life of an abrasive can be improved.

  The abrasives produced by the method of producing an abrasive according to the present invention and the abrasives according to the present invention maintain the homogeneity in the thickness direction of the abrasive layer, and therefore maintain excellent polishing rate and planarization accuracy. The life can be improved. Therefore, the said abrasives are used suitably for planar polishing of board | substrates, such as glass and sapphire.

1, 2 Abrasive material 10 Substrate 20 Abrasive layer 21 Abrasive particle 22 Filler 23 Binder 24 Groove 25 Convex part 30 Adhesive layer 31 Second adhesive layer 40 Support

Claims (5)

A method for producing an abrasive comprising: a substrate; and an abrasive layer laminated on the surface side of the substrate and containing an abrasive, a filler and a binder,
Preparing an abrasive layer composition comprising abrasive grains, a filler and a binder;
Applying the composition for polishing layer on the surface of the substrate;
And a heating step of heating the polishing layer composition after the coating step.
In the preparation step, the total content of the abrasive grains and the filler in the solid content of the composition for polishing layer is set to 60% by volume or more and 85% by volume or less.
The above heating process is
A preliminary drying step of drying the polishing layer composition at normal temperature for 30 minutes or more;
A heating and dewatering step of heating and dewatering the water of the polishing layer composition after the preliminary drying step;
And heating and curing the polishing layer composition after the heating and dewatering step.   The manufacturing method of the abrasives of Claim 1 which adjusts the coating amount of the said composition for abrasive layers so that the average thickness of an abrasive layer may be 1000 micrometers or more at the said coating process.   In the above preparation process, the wear amount by the Taber wear test of the polishing layer is 0.03 g or more and 0.15 g or less, and the wear amount between the maximum value and the minimum value by the Taber wear test measured every 500 μm in the thickness direction of the polishing layer The method for producing an abrasive according to claim 2, wherein the contents of the abrasive grains and the filler are adjusted so that the difference is 0.080 g or less.   The method for producing an abrasive according to claim 1, 2 or 3, wherein the abrasive is a diamond abrasive. An abrasive comprising: a substrate; and an abrasive layer laminated on the surface side of the substrate and containing abrasive grains, a filler and a binder,
The total content of the abrasive grains and the filler in the polishing layer is 60% by volume or more and 85% by volume or less,
The average thickness of the polishing layer is 1000 μm or more,
The wear amount by the Taber abrasion test of the polishing layer is 0.03 g or more and 0.15 g or less,
The abrasives whose difference of the maximum value and minimum value of the abrasion loss by the Taber abrasion test measured every 500 micrometers of thickness direction of abrading layer is 0.080 g or less.

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