JP2014101488A - Polishing agent for manganese oxide loose abrasives polishing to which particular dissimilar metallic element is added and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive polishing agent for manganese oxide loose abrasives polishing having a high polishing speed for glass, a stable polishing speed, not generating scratches due to polishing, and excellent in washability.SOLUTION: A polishing agent for manganese oxide loose abrasives polishing containing MnOas a major crystal phase and Al of 1 to 30 atom% based on Mn, having a BET specific surface area at firing of 1 to 4 m/g, D50 diameter, which is a 50% diameter of secondary particles of MnOparticles, of 1 to 3 μm, and containing no MnOparticles having a secondary particle diameter of 10 μm or more, is excellent in polishing performance because it has a stably high polishing speed for glass and generates no scratches due to polishing.

Description

  The present invention relates to a free abrasive polishing abrasive used for polishing liquid crystal panels, magnetic disks, optical glass, and the like, and a method for producing a free abrasive polishing abrasive.

  With the spread of liquid crystal televisions and computers, the amount of glass materials such as mother glass for liquid crystal panels, quartz glass for photomasks, and tempered glass for hard disks is increasing. Glass is also used for the optical lens. Since the surface of these glass materials needs to be mirror-finished or flattened, polishing is essential.

  In polishing glass materials, it is possible to obtain a large polishing rate by expressing not only mechanical polishing action but also chemical polishing action, and scratches such as scratches are hardly generated on the surface after polishing. Cerium oxide has been used.

  For example, in the polishing of quartz glass, which is a photomask substrate for liquid crystal, a polishing method is used in which a polishing pad made of urethane is attached to a polishing tool and a slurry in which cerium oxide abrasive grains are dispersed in water is supplied.

  Thus, cerium oxide is commonly used for polishing glass, but cerium oxide is an expensive rare earth oxide and its price is not stable, so there is a need for abrasive grains that can replace cerium oxide. It was done.

Inexpensive manganese oxide abrasive grains are known for chemical mechanical polishing (CMP) applications used for planarization of an interlayer insulating film on a semiconductor substrate. As the abrasive grains of manganese oxide, for example, a manganese dioxide lump deposited on the anode by electrolyzing an electrolyte solution containing Mn ions is heated at 500 ° C. to 900 ° C., and the formed Mn ₂ O ₃ is pulverized. A method of using the particles as abrasive grains (for example, see Patent Document 1), or using Mn ₃ O ₄ as a manganese oxide source, heat-treating to Mn ₂ O _3, and grinding or crushing this to polish abrasives A method for producing grains has been proposed (see, for example, Patent Document 2). However, in these prior arts, no consideration is given to the stability of the polishing rate.

Japanese Patent Laid-Open No. 10-60415 JP 2006-128395 A

  An object of the present invention is to provide a manganese oxide free abrasive polishing agent that is excellent in high polishing rate and polishing rate stability in polishing processing, and an economically advantageous method for producing a free abrasive polishing agent. Objective.

As a result of intensive studies, the present inventor found that a sufficient amount of Al was contained in Mn ₂ O ₃ in a manganese oxide abrasive for polishing free abrasive grains mainly composed of Mn ₂ O ₃ powder. The inventors have found that speed and polishing stability can be obtained, and have completed the present invention.

  The present invention is described in detail below.

The present invention is a manganese oxide abrasive for polishing free abrasive grains mainly composed of Mn ₂ O ₃ powder, and the Al content in the abrasive is 1 to 30 atom% when the total of Mn and Al is 100. There is a polishing agent for polishing free abrasive grains. The loose abrasive grains are those in which individual abrasive particles are in a free state.

The abrasive for polishing free abrasive grains of the present invention comprises Mn ₂ O ₃ abrasive grains as main components and a dispersion medium. Examples of the dispersion medium include distilled water, ion exchange water, alcohol, and the like, but an aqueous system is preferable for handling. Further, if necessary, a dispersant or the like can be added to the manganese oxide abrasive for polishing free abrasive grains of the present invention, and the pH can be adjusted.

Normally, when a glass substrate is continuously polished with a manganese oxide abrasive, the zeta potential, which is the potential of the abrasive, gradually decreases and finally shows a large negative value. This seems to be because, in glass polishing, negatively charged glass is mixed as polishing waste, but the inclusion of aluminum in the polishing agent manganese oxide increases the zeta potential of the polishing agent. At the same time, the decrease in zeta potential after continuous polishing is also suppressed. If the zeta potential of the polishing agent becomes large and negative, repulsion with the glass substrate that is also negative occurs, and it becomes difficult for the polishing agent to approach the glass substrate. It is considered a thing. When the total Al content in Mn ₂ O ₃ is 100, the zeta potential of the abrasive is increased by 1-30 atom%, and the polishing rate is stabilized even when continuous polishing is performed. To do. Moreover, even if it is the first polishing, if it is considered that the zeta potential decrease due to glass polishing scraps is caused during polishing, it is considered that it contributes to the improvement of the initial polishing rate. In order to obtain the above effect, the lower limit of the Al content is preferably 5 atom%, and more preferably 10 atom%.

  Moreover, you may contain what raises the zeta potential of an abrasive | polishing agent besides Al. Examples of those that increase the zeta potential include those having an isoelectric point pH higher than 8 at which the zeta potential is 0, such as iron oxide, magnesium oxide, magnesium hydroxide, lanthanum oxide, and lanthanum hydroxide. I can do it.

  Further, F (fluorine) may be added to the abrasive in a composition ratio of 1/2 to 3 times that of Al. This is because the inclusion of F which is easily negatively charged repels negatively charged glass and improves the cleanability of the polished glass substrate.

Since Mn ₂ O ₃ powder as the main component improves the polishing rate for glass, Mn ₂ O ₃ powder obtained by baking Mn carbonate or hydroxide or Mn ₃ O ₄ powder is used. preferable. Not clear about this reason it is believed that some chemical interaction between the SiO ₂ and Mn is a constituent molecule of the glass is working. It can be confirmed by using an X-ray diffraction method that the powder after firing is Mn ₂ O ₃ . As a crystal phase other than Mn ₂ O ₃ , MnAl ₂ O ₄ (galaxite), Al ₂ O ₃ or the like which is a compound of added Al may be contained in a trace amount. When F is added, aluminum oxyfluoride or aluminum fluoride such as AlOF or AlF ₃ may be contained.

Moreover, it is preferable that the specific surface area by the BET method at the time of baking of the abrasive | polishing agent for free abrasive grains of this invention is 1-4 m < ² > / g. When the specific surface area is 1 to 4 m ² / g, pores are reduced inside the abrasive grains, the particle strength is improved, and the polishing rate is increased. When it is larger than 4 m ² / g, the particles are small and the particle strength becomes weak, so that the polishing rate may decrease.

The Mn ₂ O ₃ particles used as abrasive grains preferably have a D50 diameter of 1 to 3 μm, which is a 50% diameter of secondary particles. This is because if the D50 diameter is smaller than 1 μm, the polishing rate for glass is low, and if it is larger than 3 μm, scratches may occur on the surface of the workpiece during polishing. As a method for measuring the D50 diameter, there are a laser diffraction method and an image analysis method using a scanning electron microscope.

  The secondary particle shape of the abrasive grains is preferably spherical or equiaxed. When the shape is spherical or equiaxed, it is considered that the strength of the polishing powder is increased and a high polishing rate can be obtained. Moreover, since there are few sharp parts, it becomes difficult to generate | occur | produce a damage | wound on the surface of a workpiece at the time of grinding | polishing.

In addition, it is preferable that the abrasive for polishing free abrasive grains of the present invention does not contain Mn ₂ O ₃ particles having a secondary particle diameter of 10 μm or more. This is because if Mn ₂ O ₃ particles having a secondary particle diameter of 10 μm or more are present in the abrasive, scratches are likely to occur on the surface of the workpiece during polishing.

  Next, the manufacturing method of the abrasive | polishing agent for loose abrasive polishing of this invention is demonstrated.

The abrasive for polishing free abrasive grains of the present invention has a precursor containing Mn and Al (hereinafter, simply referred to as a precursor) having an Al content of 1 to 30 atom% when the total of Mn and Al is 100. In some cases, it is fired so that the main crystal phase is Mn ₂ O ₃ , and the obtained Mn ₂ O ₃ is added to the dispersion medium.

Examples of the precursor include carbonates and hydroxides of Mn and Al, Mn ₃ O ₄ powder containing Al, and the like.

Examples of the method for producing the precursor include a method of crystallizing carbonates and hydroxides of Mn and Al, a method of adding a compound that becomes an Al source during the synthesis of Mn ₃ O ₄ powder, and the like. Specifically, it can be obtained by a method of neutralizing a mixed solution of a manganese salt aqueous solution such as manganese sulfate or manganese nitrate and an aluminum salt aqueous solution such as aluminum sulfate using an alkali carbonate such as sodium carbonate, It is not limited to this. The wet synthesis method as described above is preferable because Mn and Al can be uniformly mixed by adding an Al compound during synthesis, and the dispersion of Al after firing is excellent.

The precursor Mn ₃ O ₄ powder is obtained by, for example, a method obtained by oxidizing manganese hydroxide generated by a hydrolysis reaction of manganese metal, or a method of neutralizing and oxidizing a manganese sulfate salt with a basic aqueous solution. However, the present invention is not limited to this.

In addition, as a compound serving as an Al source, aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum carbonate, aluminum fluoride, aluminum phosphate, aluminum acetate, aluminum oxalate, aluminum lactate, aluminum stearate It is preferable to use one or more selected from the group consisting of aluminum acrylate. Since these aluminum compounds are dissolved in a dispersion medium and water as a solvent during mixing, or are dispersed in a slurry state, uniform mixing with manganese oxide becomes possible. Above all, when an aluminum compound that dissolves in water or an aluminum compound having a specific surface area of 50 m ² / g or more by the BET method is used, mixing and dispersion with manganese oxide are promoted, so that aluminum diffuses during firing. preferable.

When F is added to the precursor, a method of simultaneously adding Mn and Al carbonates and hydroxides to crystallize, a method of adding Mn ₃ O ₄ powder as a precursor raw material, a precursor, A method of adding an F compound before firing the body can be used. Examples of the F source include sodium fluoride and aluminum fluoride. In particular, a method using a fluoride that dissolves in water, such as sodium fluoride, is preferable because it allows more uniform mixing of F. However, it is a fluoride that is hardly soluble in water, such as aluminum fluoride. However, there is no particular problem because uniform mixing is possible by slurrying.

As the size of the precursor powder, the primary particle diameter is preferably 0.001 to 3 μm, and the D50 diameter of the secondary particles is preferably 1 to 5 μm. If the D50 diameter of the secondary particles is smaller than 1 μm, the particle size of the particles whose main crystal phase after firing is Mn ₂ O ₃ is small, so the polishing rate is low. If the D50 diameter of the secondary particles is larger than 5 μm, the D50 diameter of the secondary particles of the Mn ₂ O ₃ particles is the main crystal phase after firing, and the surface of the workpiece is likely to be damaged during polishing. Become. As a method for measuring the D50 diameter of the secondary particles, there are a laser diffraction method and an image analysis method using a scanning electron microscope.

  In order to set the D50 diameter of the secondary particles of the precursor powder to 1 to 5 μm, granulation may be performed. In particular, as a method for uniformly forming 1 to 5 μm, for example, a method of slurrying the precursor powder and spray drying can be mentioned.

  When there are aggregated particles of the precursor powder during spray drying, it is preferable to perform ball milling or bead milling in advance. As the grinding media, ceramics such as alumina and zirconia are preferable because of high grinding efficiency. Moreover, when adding an aluminum compound, in order to mix uniformly, it is preferable to perform a ball mill and bead mill.

When a precursor powder having a small primary particle size is made into a slurry and granulated by a spray drying method, it is preferable to perform spray drying in a state where substances in the slurry are well dispersed. Examples of the dispersion medium include ion exchange water, distilled water, alcohol and the like. By spray-drying the dispersed slurry, the constituent particles in the granulated powder are evenly arranged without unevenness, so that the particle size of the Mn ₂ O ₃ particles becomes uniform during subsequent firing.

  The spray drying method is not particularly limited, but in order to produce granulated particles having an average particle size of 1 to 5 μm, a spray using an ultrasonic nozzle method or a multi-fluid nozzle that ejects slurry by compressed air. It is preferable to use a dryer. Examples of the multi-fluid nozzle for injecting slurry with compressed air include a two-fluid nozzle, a three-fluid nozzle, and a four-fluid nozzle.

Next, the main crystal phase is made into Mn ₂ O ₃ powder by firing the precursor powder. The firing temperature is preferably from 750 ° C. to 950 ° C., and the firing time is preferably from 3 hours to 50 hours. By setting the firing temperature to 750 ° C. or more and 950 ° C. or less and the firing time to 3 hours or more and 50 hours or less, oxidation is promoted so that the main crystal phase becomes Mn ₂ O ₃ and simultaneously granulated particles or secondary particles By promoting the inner sintering, the BET specific surface area after firing becomes 1 to 4 m ² / g, the particle strength is improved, and the polishing rate is improved. If the firing temperature is lower than 750 ° C. or the firing time is shorter than 3 hours, the particles are in a necked state and are not sintered so much, so there are many pores, so the strength of the particles is low, and the polishing rate Tend to be lower.

As an atmosphere to be baked, an atmosphere to be oxidized, for example, an atmosphere in air, an air circulation atmosphere, or an oxygen gas circulation atmosphere can be given. A reducing atmosphere is not preferable because an oxidation reaction to Mn ₂ O ₃ does not occur.

  Although it does not specifically limit as a method of baking precursor particle | grains, Using a box furnace, a ring furnace, and a rotary kiln is mentioned. In particular, a rotary kiln is preferred because it can prevent the temperature applied to the powder from being uniform and aggregation of secondary particles due to firing.

Since particles having Mn ₂ O ₃ as the main crystal phase obtained by firing may be aggregated, the aggregated particles are sintered in order to make the D50 diameter of secondary particles 1 to 3 μm. It is preferable to further pulverize and / or pulverize particles whose main crystal phase is Mn ₂ O ₃ .

  Examples of the pulverization and / or pulverization method include a ball mill and a bead mill. As the grinding media, ceramics such as alumina and zirconia are preferable because of high grinding efficiency.

  The abrasive for polishing free abrasive grains of the present invention has a sufficient polishing rate, and can be used for polishing various materials because it hardly causes scratches on the surface of the workpiece during polishing. It can be suitably used for glass materials such as mother glass, quartz glass for photomasks and tempered glass for hard disks.

  The manganese oxide loose abrasive polishing slurry of the present invention has a sufficient polishing rate and polishing stability, and is difficult to cause scratches on the surface of the workpiece during polishing, so that it can be used for polishing various materials. It can be used and can be manufactured at low cost.

The transition of the polishing rate for every polishing batch of the abrasive | polishing agent for manganese oxide free abrasive | polishing abrasive | polishing abrasive | polishing agent which has not added Al and what added Al is shown. It shows the transition of the zeta potential for each polishing batch of an abrasive for polishing manganese oxide free abrasive grains with and without adding Al.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not restrict | limited to these Examples at all.

Example 1
As Mn ₃ O ₄ powder, Tosoh's Brownox (primary particle size 0.08 μm) is used as an Al source, and Taymicron TM-300D (BET specific surface area 200 m ² / g) is a γ-type aluminum oxide. Was used. γ-type aluminum oxide was added to the Mn ₃ O ₄ powder so that Al was 10 atom% with respect to the amount of Mn. Distilled water ion-exchanged with respect to the mixed powder of γ-type aluminum oxide and Mn ₃ O ₄ was added so as to have a slurry concentration of 45%, and Kao-made Poise 530 as an anionic dispersant was used as Mn ₃ O _4. 1.5 wt% was added to the amount of powder. Ball milling for 24 hours was performed using alumina balls having a diameter of 10 mm to prepare an Mn ₃ O ₄ slurry to which Al was added.

The slurry is granulated and dried under the conditions of an inlet temperature of 200 ° C. and an air volume of 1.00 m ³ / min using a spray dryer (trade name “MDL-050M” manufactured by Fujisaki Electric Co., Ltd.), which is a four-fluid nozzle system, and aluminum. An additive Mn ₃ O ₄ granulated product was obtained. The D50 diameter of the secondary particles measured by a particle size distribution meter (manufactured by Shimadzu Corporation, trade name “SALD-7100”) was 3.5 μm.

The Al-added Mn ₃ O ₄ granulated product was baked at 900 ° C. for 24 hours using a box-type electric furnace. The atmosphere for firing was air. The powder obtained by baking was identified by a X-ray diffractometer (trade name “RINT Ultimate III”, manufactured by Rigaku Corporation), and it was confirmed that the main crystal phase was Mn ₂ O ₃ . The specific surface area of the calcined powder according to the BET method was 1.5 m ² / g.

The main crystal phase obtained by firing is SC mill (trade name “SC150” manufactured by Mitsui Mining Co., Ltd.) for Mn ₂ O ₃ powder, and ion-exchanged distilled water and φ1 mm zirconia beads are used as grinding media. A wet bead mill was used. The grinding time was 10 minutes per kg of solid content. As a result of measuring the obtained slurry with a particle size distribution diameter (manufactured by Shimadzu Corporation, trade name “SALD-7100”), the D50 diameter of the secondary particles was 1.0 μm, and there were no abrasive grains of 10 μm or more. In addition, Al content measurement by ICP emission analysis method and BET specific surface area by BET measuring device (trade name “MONOSORB” manufactured by Yuasa Ionics Co., Ltd.) are measured for abrasive grains dried from the polishing slurry, and Al content is measured. Was 10 atom%, and the BET specific surface area was 6.9 m ² / g.

(Example 2)
A slurry was prepared under the same conditions as in Example 1 except that the amount of γ-type aluminum oxide added was 20 atom% with respect to the amount of Mn. The slurry was granulated and dried under the same conditions as in Example 1 and fired under the same conditions as in Example 1. The specific surface area of the powder after baking according to the BET method was 1.7 m ² / g.

A slurry was obtained in the same manner as in Example 1 using the powder after firing. The D50 diameter of the secondary particles was 1.7 μm, and there were no abrasive grains of 10 μm or more. The Al content was 20 atom%, and the BET specific surface area was 8.8 m ² / g.

(Example 3)
A slurry was prepared under the same conditions as in Example 2. The slurry was granulated and dried under the same conditions as in Example 1, and calcined under the same conditions as in Example 2 except that the calcining time was 8 hours. The specific surface area of the powder after baking according to the BET method was 4.0 m ² / g.

A slurry was prepared in the same manner as in Example 2 using the powder after firing. The D50 diameter of the secondary particles was 1.2 μm, and there were no abrasive grains of 10 μm or more. The Al content was 20 atom%, and the BET specific surface area was 7.7 m ² / g.

Example 4
A slurry was prepared under the same conditions as in Example 2. The slurry was granulated and dried under the same conditions as in Example 1, and calcined under the same conditions as in Example 2 except that the calcining time was 48 hours. The specific surface area of the powder after baking according to the BET method was 1.7 m ² / g.

A slurry was prepared in the same manner as in Example 2 using the powder after firing. The D50 diameter of the secondary particles was 1.1 μm, and there were no abrasive grains of 10 μm or more. The Al content was 20 atom%, and the BET specific surface area was 8.0 m ² / g.

(Example 5)
A 1 mol / L aqueous solution of manganese sulfate (manufactured by Wako Pure Chemical Industries) and a 0.5 mol / L aqueous solution of aluminum sulfate (manufactured by Wako Pure Chemical Industries) with respect to a 1 mol / L aqueous solution of sodium hydroxide (manufactured by Wako Pure Chemical Industries) heated to 50 ° C. Sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) 1 mol / L aqueous solution mixed so that Al is 10 atom% with respect to Mn was added dropwise under the conditions of 1 L / min so as to have a manganese carbonate and aluminum hydroxide composition. Manganese oxide abrasive precursor was synthesized. After filtration, the powder was sufficiently dried in a drying oven, and the pulverized powder was baked at 750 ° C. for 8 hours using a box-type electric furnace. The atmosphere for firing was air. The constituent phase of the powder obtained by firing was identified by an X-ray diffractometer, and it was confirmed that the main crystal phase was Mn ₂ O ₃ . The specific surface area of the powder after baking according to the BET method was 2.2 m ² / g.

The main crystal phase obtained by firing was ball milled with alumina balls on Mn ₂ O ₃ powder, and the resulting slurry was measured by particle size distribution. As a result, the D50 diameter of the secondary particles was 2 .2 μm, and there were no abrasive grains of 10 μm or more.

(Example 6)
1 mol / L manganese sulfate (manufactured by Wako Pure Chemical Industries) is mixed with a 1 mol / L aqueous solution of sodium hydroxide (manufactured by Wako Pure Chemical Industries) heated to 50 ° C and a 1 mol / L aqueous solution of sodium fluoride (Wako Pure Chemical Industries). A solution obtained by mixing an aqueous solution, an aluminum sulfate (manufactured by Wako Pure Chemical Industries) 0.5 mol / L aqueous solution and an aqueous solution of sodium carbonate (manufactured by Wako Pure Chemical Industries) 1 mol / L so that Al is 25 atom% with respect to Mn, manganese carbonate, A manganese oxide abrasive precursor was synthesized by adding dropwise under conditions of 1 L / min so as to obtain an aluminum hydroxide fluoride composition. The fluorine content was adjusted to be the same as Al. After filtration, the powder was sufficiently dried in a drying oven, and the pulverized powder was baked at 750 ° C. for 8 hours using a box-type electric furnace. The atmosphere for firing was air. The constituent phase of the powder obtained by firing was identified by an X-ray diffractometer, and it was confirmed that the main crystal phase was Mn ₂ O ₃ . The specific surface area of the powder after firing according to the BET method was 1.0 m ² / g.

The main crystal phase obtained by firing was ball milled with Mn ₂ O ₃ powder using alumina balls. As a result of measuring the obtained slurry by the particle size distribution diameter, the D50 diameter of the secondary particles was 1.8 μm, and there were no abrasive grains of 10 μm or more.

(Comparative Example 1)
A slurry was prepared under the same conditions as in Example 1 except that no Al source was added. The slurry was granulated and dried under the same conditions as in Example 1 and baked under the same conditions as in Example 1 except that the baking time was 8 hours. The specific surface area of the powder after firing according to the BET method was 1.0 m ² / g.

A slurry was obtained in the same manner as in Example 1 using the powder after firing. The D50 diameter of the secondary particles was 1.1 μm, and there were no abrasive grains of 10 μm or more. The BET specific surface area was 6.5 m ² / g.

(Comparative Example 2)
Tosoh Brownox, to which Al was not added, was baked at 900 ° C. for 24 hours in an air atmosphere in a box-type electric furnace without spray drying. The atmosphere for firing was air. The constituent phase of the powder obtained by firing was identified by an X-ray diffractometer, and it was confirmed that the main crystal phase was Mn ₂ O ₃ . The specific surface area of the powder after baking according to the BET method was 0.7 m ² / g.

Wet ball milling using alumina balls with a diameter of 10 mm as the main crystal phase obtained by firing on Mn ₂ O ₃ powder was performed for 5 hours. The D50 diameter of the secondary particles of the obtained slurry was 5.2 μm, and abrasive grains of 10 μm or more existed. Further, the BET specific surface area was 3.0 m ² / g.

(Polishing evaluation)
Three quartz glass substrates of 34 mm × 34 mm were set in a polishing apparatus (trade name “LGP-15AF” manufactured by LAPMASTER SFT), and the slurry of Examples 1 to 6 and Comparative Example 1 obtained by the SC mill were used. Ion-exchanged distilled water was added to adjust the concentration to 25% to obtain a polishing slurry. Using the slurry, 5 to 6 batches of 2 hours of free abrasive polishing were performed. The polishing pad was an IC1000 manufactured by Nitta Haas, the polishing pressure was 215 g / cm ² , and the rotation speed of the glass and the tool was 45 rpm. For the slurries of Examples 5 and 6 and Comparative Example 2, only one batch was polished.

  The glass substrate after processing evaluated the polishing rate for each batch from the weight change before and after polishing. Further, for Examples 1 to 4 and Comparative Example 1, after the completion of 5 to 6 batch polishing, for Examples 5 and 6 and Comparative Example 2, the presence or absence of scratches by visual observation was evaluated on the substrate after 1 batch. . Moreover, about Examples 1-4 and the comparative example 1, the zeta potential before grinding | polishing of the 1st batch and after grinding | polishing of each batch was measured with the zeta potentiometer (ELSZ-2 by Otsuka Electronics).

  The results of the abrasive properties are shown in Table 1, the change in polishing rate is shown in FIG. 1, and the change in zeta potential after polishing is shown in FIG. The polishing rate of Al addition prepared in Examples 1 to 4 was 21 to 27 μm / h in the first batch, and the polishing rate ratio in the 5th to 6th batch was 80% or more compared to the first batch. Moreover, although the zeta potential was initially 15 to 21 mV, it became -17 to -30 mV after the end of 5 to 6 batches, but the decrease was gradual. The polishing rate without addition of Al, which is Comparative Example 1, is 20 μm / h, which is lower than that with addition of Al, and the polishing rate ratio of the sixth batch was 78% of the first batch. Also, the zeta potential was initially 7 mV, which was low, and decreased rapidly with each polishing batch and decreased to −37 mV.

  In Comparative Example 2, the polishing rate was as low as 19 μm / h, and visual scratches were present on the glass surface after one batch polishing.

  The substrate cleanability after polishing was good in Examples 1 to 6, and Example 6 to which fluorine was added was particularly good.

Claims (10)

A manganese oxide abrasive for polishing free abrasive grains mainly composed of Mn ₂ O ₃ powder, wherein the Al content in the abrasive is 1 to 30 atom% when the total of Mn and Al is 100. A polishing agent for polishing manganese oxide free abrasive grains. The polishing agent for polishing manganese oxide free abrasive grains according to claim 1, wherein the main component is Mn ₂ O ₃ powder obtained by firing Mn ₃ O ₄ powder.   The abrasive for polishing manganese oxide free abrasive grains according to claim 1 or 2, wherein F is contained in an amount of 1/2 to 3 times the composition ratio of Al. The abrasive for polishing manganese oxide free abrasive grains according to any one of claims 1 to 3, wherein the abrasive has a BET specific surface area of 1 to 4 m ² / g. The D50 diameter which is a 50% diameter of the secondary particles of the abrasive is 1 to 3 μm, and does not contain Mn ₂ O ₃ particles having a secondary particle diameter of 10 μm or more. A polishing agent for polishing manganese oxide free abrasive grains according to any one of the above. A precursor containing Mn and Al, which has an Al content of 100 to 30 atom% when the total content of Mn and Al is 100, is fired so that the main crystal phase is Mn ₂ O _3. A method for producing a polishing material for polishing manganese oxide free abrasive grains.   The method for producing an abrasive for polishing manganese oxide free abrasive grains according to claim 6, wherein the precursor is a carbonate or hydroxide of Mn and Al. The method for producing an abrasive for polishing manganese oxide free abrasive grains according to claim 6, wherein the precursor is Mn ₃ O ₄ powder containing Al.   9. The production of an abrasive for polishing manganese oxide free abrasive grains according to claim 6, wherein the firing temperature is 600 ° C. or more and 950 ° C. or less, and the firing holding time is 3 hours or more and 50 hours or less. Method.   The method for producing an abrasive for polishing manganese oxide free abrasive grains according to any one of claims 6 to 9, wherein the precursor is granulated by spray drying before firing.

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