JP3365993B2 - Cerium-based abrasives, raw materials therefor, and methods for producing them - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cerium-based abrasive, a raw material therefor, and a method for producing them. More specifically, the present invention relates to a technique for producing a cerium-based abrasive having excellent polishing power and polishing accuracy and its raw material with high productivity and low cost.

[0002]

2. Description of the Related Art In recent years, glass materials have been used for various purposes. Among them, especially glass substrates for optical disks and magnetic disks, active matrix type LCDs, liquid crystal T
V color filter, clock, calculator, camera LCD,
High-precision surface polishing is required for glass substrates for displays such as solar cells, glass substrates for LSI photomasks, glass substrates such as optical lenses and optical lenses.

Conventionally, as an abrasive used for polishing the surface of these glass substrates, an abrasive containing a rare earth oxide, especially cerium oxide as a main component has been used. The reason is that the polishing efficiency of cerium oxide is several times superior to that of zirconium oxide and silicon dioxide in polishing glass.

As a raw material used for the cerium-based abrasive, a rare earth raw material such as rare earth carbonate, rare earth hydroxide, rare earth oxalate, or a rare earth oxide raw material obtained by firing them is generally used. Used. These rare earth materials are generally produced by removing some rare earth (Nd, Pr) and radioactive materials from a bastnasite rare earth material or a cerium-containing rare earth material by a known chemical treatment. There is.

By the way, a cerium-based abrasive made from rare earth carbonate or rare earth oxide is manufactured as follows. First, the raw material is slurried or wet-milled, treated with a mineral acid, and then, if necessary, treated with hydrofluoric acid, ammonium fluoride or the like. The resulting slurry is filtered, dried and then roasted. Finally, it is crushed and classified to obtain an abrasive having a predetermined particle size.

However, the rare earth carbonate raw material has a very high ignition loss of about 30%. Therefore, when using a rare earth carbonate raw material, it is necessary to use a considerably large amount of raw material with respect to the weight of the final product when manufacturing the abrasive.
Raw material cost becomes high. Moreover, since the roasting efficiency does not increase and the bulk density of the pulverized product also decreases, the classification ability also decreases. For these reasons, manufacturing costs are very high.

In order to solve such a problem, there is also known a method for producing a rare earth oxide obtained by firing rare earth carbonate or the like as a raw material. According to this method, the loss on ignition is small, the raw material cost can be kept low, and the bulk density can be made higher than that of the rare earth carbonate. Therefore, productivity can be increased. However, when rare earth oxide is used as a raw material, there is a risk that the sintering will progress non-uniformly in the roasting step and the bulk density will become too high. For this reason, although the obtained abrasive is excellent in polishing power, there is a possibility that fine scratches may be made on the glass surface or the like.
Therefore, applications that require high polishing accuracy (for example,
In the above-mentioned high-performance glass), higher polishing accuracy is required.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and produces a cerium-based abrasive having excellent polishing power and polishing accuracy and its raw material at high productivity and at low cost. This is an issue.

[0009]

That is, the raw material for cerium-based abrasives of the present invention is a raw material used in the production of cerium-based abrasives, and is composed mainly of cerium-based rare earth carbonates and cerium-based rare earth oxides. Included as 10
The loss on ignition when heated at 00 ° C. for 1 hour is 0.5 to 25% on a dry weight basis.

The first method for producing a raw material for a cerium-based abrasive according to the present invention is to prepare a cerium-based rare earth carbonate and a cerium-based rare earth oxide, and to prepare the raw material at 1000 ° C.
Loss on ignition when heated for 1 hour at 0.
This is to obtain a composite raw material by mixing in a weight ratio of 5 to 25%.

A second method for producing a raw material for a cerium-based abrasive according to the present invention is to prepare a cerium-based rare earth carbonate,
A method of obtaining a composite raw material containing a cerium-based rare earth carbonate and a cerium-based rare earth oxide by calcining the raw material and changing a part thereof into a cerium-based rare earth oxide, the method comprising: The calcination temperature and the calcination time at that time are adjusted so that the ignition loss when the raw material after the calcination is heated at 1000 ° C. for 1 hour is 0.5 to 25% on a dry weight basis. It is a thing.

Further, in the method for producing a cerium-based abrasive according to the present invention, the above raw material or the raw material produced by the above method is prepared, and the raw material is slurried and / or wet pulverized and treated with a mineral acid. It is filtered, dried and roasted. Here, the raw material may be treated with ammonium fluoride and / or hydrofluoric acid after the mineral acid treatment and before the filtration. The present invention also provides a cerium-based abrasive manufactured by the above method or a cerium-based abrasive manufactured using the above-mentioned raw materials.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Cerium-based Abrasive Raw Material The cerium-based abrasive raw material according to the present invention is a raw material used in the production of a cerium-based abrasive, and contains cerium-based rare earth carbonate and cerium-based rare earth oxide. It is contained as a main component. The raw material of the present invention has a loss on ignition within a predetermined range.

Here, the loss on ignition is generally known as a percentage of weight loss when a material is heated to a prescribed temperature condition. The loss on ignition in the present invention is 10
It refers to the loss on ignition when heated at 00 ° C. for 1 hour, and is measured according to JIS-K-0067 (1992). This JIS standard can be easily obtained from the Japanese Industrial Standards (4-1-24 Akasaka, Minato-ku, Tokyo, Japan) together with its English translation. Here, the temperature condition of 1000 ° C. was set in consideration of the TG (thermogravimetric analysis) result of the rare earth carbonate, in which the amount of weight loss decreases from about 500 ° C. to almost no weight loss above 900 ° C. Then, it was thought that a stable value could be obtained at 1000 ° C.

The ignition loss is specifically measured as follows.
To be done. First, weigh the crucible with a constant weight.
It Then, put the dried raw material sample in the crucible and weigh it.
After the measurement, in an electric furnace kept at 1000 ° C for over 1 hour
heat. After heating, quickly transfer the crucible to a desiccator.
Allow to cool. After allowing to cool, remove it from the desiccator and
Measure the quantity. Based on this measurement result, the ignition loss is
Calculate based on. B = (W₁-W_Two) / (W₁-W_Three) X 100 [Where B: loss on ignition (%), W₁: With sample before ignition
Crucible weight (g), W _Two: Weight of sample and crucible after ignition
Amount (g), W_Three: Crucible weight] In addition, JIS-K-0067 describes the crucible and the sample.
Repeating ignition, cooling, and weighing until the weight becomes constant
It is regulated, but the weight difference between the first and second times is almost
If you think that there is no problem in accuracy,
It suffices to weigh only once each. Also dry
When measuring the loss on ignition based on dry weight, make sure that the sample is
Must be dry. This drying is, for example,
"4.1 described in JIS-K-0067 (1992).
  It is possible to use the sample obtained in accordance with "Drying loss test".
it can. Specifically, under atmospheric pressure, the drying temperature 105
Dry using a dryer set to ℃ until a constant weight is reached.
Different samples can be used. Where to dry the loss on ignition
Cerium-based rare earth carbonates are usually set as weight standards.
Salt contains a large amount of water, and the water content is not constant.
Therefore, in the loss on ignition measured directly without drying,
This is because it cannot be a useful index due to the influence.

The raw material in the present invention has a loss on ignition of 0.5 to 2 on a dry weight basis when heated at 1000 ° C. for 1 hour.
5%, preferably 1-25%, more preferably 5-25
%, Most preferably 7 to 20%. By setting the ignition loss within the above range, when the raw material is used for the production of a cerium-based abrasive, an excessive raw material is not required, and thus the raw material cost is reduced. Moreover, the roasting efficiency is improved, and at the same time, the sintering can be uniformly advanced, and an appropriate bulk density can be obtained. For this reason,
It is possible to obtain a cerium-based abrasive which has improved classification ability and improved productivity and is excellent in both polishing power and polishing accuracy. In particular, the polishing material obtained when the loss on ignition is 5 to 25% (most preferably 7 to 20%) has remarkably excellent polishing accuracy and has an advantage that the surface to be polished is hardly scratched. Suitable for secondary polishing (final finishing polishing) of highly functional glass such as glass substrates for optical disks and magnetic disks. On the other hand, the polishing material obtained when the loss on ignition is 0.5 to 5% (preferably 1 to 5%) is slightly inferior in polishing accuracy, but is excellent in polishing power. It is suitable for applications such as polishing where polishing accuracy is not so required.

The cerium-based rare earth carbonate (hereinafter, also referred to as rare earth carbonate) in the present invention has the general formula R ₂ (CO ₃ ) ₃
A compound represented by nH ₂ O, which is usually a rare earth-containing solution in which impurities such as fluorine are reduced by chemically treating a cerium-based rare earth ore such as a bastnasite concentrate, and a carbonate such as ammonium hydrogen carbonate. It is obtained by adding an agent and filtering. Further, neodymium or the like serving as a magnet raw material may be recovered from the rare earth-containing solution by solvent extraction before carbonation. The presence of rare earth carbonate is, for example, X-ray diffraction,
TG / DTA (Thermogravimetry / Differential Therm
al Analysis) or the generation of gas (bubbles) when an acid is added. Further, the gas generated when the acid is added can be identified as carbon dioxide by infrared spectroscopic analysis or the like.

The cerium-based rare earth oxide (hereinafter also referred to as rare earth oxide) in the present invention is obtained by firing a rare earth oxalate, hydroxide, carbonate, basic sulfate, basic nitrate or the like. It can be obtained as a mixed rare earth oxide. Here, in the cerium-based rare earth oxide in the present invention, an intermediate product that can occur during firing of the above various salts, for example, that can occur when cerium-based rare earth carbonate is calcined, complete cerium-based rare earth oxidation Also included are non-productive intermediate products.

Each of these rare earth carbonates and rare earth oxides contains cerium as a main component. Thereby, excellent polishing power can be obtained. In the composite raw material of the present invention, the contents of the rare earth carbonate and the rare earth oxide are not particularly limited as long as they are within the above-mentioned predetermined ignition loss range. The rare earth carbonates and rare earth oxides of the present invention are both rare earths (La, Pr, Nd, etc.) other than cerium.
However, it is desirable that the amount of these rare earth components is smaller than that of cerium. Further, these rare earth compounds include F, Ca, Ba, P,
A small amount of unavoidable impurities such as Si and Fe may be contained.

According to a preferred embodiment of the present invention, the ratio of CeO _{2 in} the total rare earth oxide equivalent (TREO) is 40.
It is preferably not less than 50% by weight, more preferably not less than 50% by weight. By setting it within such a range,
More excellent polishing power can be realized.

Manufacturing Method of Raw Material for Cerium-Based Abrasive Material The manufacturing method of the raw material for cerium-based abrasive material of the present invention, in particular, the method of controlling the ignition loss within the above range is not particularly limited, but the preferred manufacturing method is as follows. There are two methods.

In the first production method of the present invention, first, a cerium-based rare earth carbonate and a cerium-based rare earth oxide are prepared. The rare earth carbonate and the rare earth oxide are as described above. Here, it is desirable that the loss on ignition of these raw materials be known upon use.
This is because it becomes possible to finely control the loss on ignition to a desired value. Even if this ignition loss is unknown, it can be easily known by performing the above-described measurement method. Further, as a typical value of ignition loss when ignited at 1000 ° C. for 1 hour, a value of about 30% for a cerium-based rare earth carbonate and a value of about 0.5% for a cerium-based rare earth oxide can be mentioned. However, it is not limited to this. By referring to these representative values,
The above-mentioned rare earth carbonate and rare earth oxide can be used as a raw material without strict measurement of ignition loss.

Next, the loss on ignition when these two raw materials were heated at 1000 ° C. for 1 hour was 0.5 on a dry weight basis.
-25%, preferably 1-25%, more preferably 5-
The composite raw material is obtained by mixing in a weight ratio of 25%, most preferably 7 to 20%. Specifically, the rare earth oxide raw material and the rare earth carbonate raw material may be weighed and mixed so that the weight ratio satisfies the following formula. The mixing method is not particularly limited, and various methods can be adopted and are not particularly limited. For example, a wet or dry ball mill, a V-type mixer, or the like is preferable in that uniform mixing is possible. The composite raw material thus obtained is the raw material targeted by the present invention. _{B = B A × W A /} (W A + W B) + B B × W B
/ (W _A + W _B ) [B; target loss on ignition (0.5 to 25%), B _A ;
Ignition loss of rare earth oxide raw material, B _B; ignition loss of the rare earth carbonate material, W _A; the dry weight of the rare earth oxide raw material, W _B; the dry weight of the rare earth carbonate material]

The advantage of this first production method is that when both the rare earth oxide raw material and the rare earth carbonate raw material are available, they are mixed in a specific weight ratio, and the desired ignition loss is obtained by a very simple method. It can be adjusted to the raw material of.

In the second production method of the present invention, first, a cerium-based rare earth carbonate is prepared. The cerium-based rare earth carbonate is as described above. Next, the raw material is calcined, and a part thereof is changed to a cerium-based rare earth oxide to obtain a composite raw material containing a cerium-based rare earth carbonate and a cerium-based rare earth oxide. That is, the calcination decomposes the carbonate into an oxide. Here, the calcination temperature and the calcination time during calcination are 0.5 to 25% on a dry weight basis when the raw material after the calcination is heated at 1000 ° C. for 1 hour.
It is adjusted to preferably 1 to 25%, more preferably 5 to 25%, and most preferably 7 to 20%. The calcination temperature and the calcination time may be appropriately determined so as to obtain a desired ignition loss, and are not particularly limited. The preferred calcination temperature is 150 to 800 ° C, more preferably 300 to 600 ° C, and further preferably 30.
It is 0 to 500 ° C. Moreover, the preferable calcination time at the suitable temperature is within 60 hours, more preferably 10 minutes to 24 hours, further preferably 20 minutes to 10 hours, and most preferably 30 minutes to 1 hour.

The advantage of this second production method is that the starting material is only one kind of rare earth carbonate material, and there is no need to mix two or more kinds of materials, which is economical and has high productivity. Moreover, it is possible to adjust to a desired raw material of ignition loss by a very simple method of performing calcination and controlling the temperature and time.

Method for Producing Cerium-Based Abrasive Material In the method for producing a cerium-based abrasive material according to the present invention, the above-mentioned raw material for cerium-based abrasive material is prepared, and the raw material is slurried and / or wet-ground, and if necessary, Treated with mineral acid and optionally ammonium fluoride and / or
Alternatively, it is carried out by treating with hydrofluoric acid, filtering, drying and roasting. These steps are general steps for producing a cerium-based abrasive, and the details thereof are not particularly limited.

First, the raw material for the cerium-based abrasive of the present invention is slurried and / or wet-ground to a predetermined particle size. Wet grinding can be performed with a wet ball mill or the like.
The preferable average particle size is 0.05 to 3 μm.

According to a preferred embodiment of the present invention, the slurry and / or wet-milled raw material powder is treated with a mineral acid. Examples of the mineral acid include hydrochloric acid, sulfuric acid, nitric acid and the like, and the concentration thereof is preferably 0.1 to 2N. By treating the rare earth raw material with a mineral acid in this manner, impurities such as alkali metals such as calcium and sodium and alkaline earth metals that cause grain growth in the roasting process are dissolved and removed, and abnormal grain growth is less likely to occur. be able to.

According to a preferred embodiment of the present invention,
This mineral acid-treated cerium-containing rare earth raw material slurry can be treated with ammonium fluoride and / or hydrofluoric acid. This ammonium fluoride and / or hydrofluoric acid includes, for example, ammonium hydrogen fluoride (NH ₄ F
• Compounds such as HF) can also be included. At this time, by adjusting the amount of fluorine, the degree of grain growth of the abrasive particles can be controlled in the roasting step performed in the subsequent step, and the machinability can be adjusted, so that from the rough finish to the final finish. High precision abrasives can be manufactured over a wide range of applications. The concentration of fluorine added is 5
It is preferably -60 g / L. Further, according to another preferred embodiment of the present invention, the raw material may be treated with ammonium fluoride and / or hydrofluoric acid after the slurrying and / or the wet pulverization, without the mineral acid treatment. .

According to a preferred embodiment of the invention, treatment with ammonium fluoride is preferred. This is because ammonium fluoride allows the fluorination reaction to proceed slowly, so that the fluorine source can be uniformly distributed in the raw material, and uniform grain growth can be promoted at a lower roasting temperature. As a result, it is possible to obtain an abrasive material that does not have abnormally coarse particles in the abrasive material, can have a highly accurate surface finish, and has high machinability.

The cerium-containing rare earth raw material which has been treated with a mineral acid or further with ammonium fluoride and / or hydrofluoric acid is filtered, dried and then roasted. The roasting temperature is preferably 600 to 1100 ° C, more preferably 700 to 1000 ° C. Also, the roasting time is 1 to
Ten hours is preferred, for example an electric furnace is used.

The roasted raw material is then allowed to cool, crush,
The cerium-based abrasive of the present invention is obtained by undergoing classification. The average particle size of this abrasive is preferably 0.05 to 3.0 μm. Further, in the abrasive, when treated with ammonium fluoride and / or hydrofluoric acid, fluorine content of 0.
The content is 5 to 15% by weight, preferably 1 to 10% by weight. By controlling the roasting temperature and the fluorine content, the particle size of the abrasive can be controlled.

Cerium-based Abrasive Material The cerium-based abrasive material of the present invention is usually used in the form of a slurry of about 5 to 30% by weight dispersed in a dispersion medium such as water. Water or a water-soluble organic solvent is used as such a dispersion medium. Examples of the organic solvent include alcohols, polyhydric alcohols, acetone, tetrahydrofuran and the like, but water is usually used.

The cerium-based abrasive of the present invention preferably contains a polymeric organic dispersant. Examples of such organic dispersants include polyacrylic acid salts such as sodium polyacrylate, carboxymethyl cellulose, polyethylene oxide, polyvinyl alcohol and the like. By containing such an organic dispersant,
It is possible to prevent foaming during polishing. The content of this organic dispersant is 0.1 to 0.8% by weight in the abrasive, and even if it is contained in excess of this amount, there is no use effect.

[0036]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 A cerium-based rare earth oxide (made in China) was prepared as a raw material A, and a cerium-based rare earth carbonate (made in China) was prepared as a raw material B. Table 1 shows the loss on ignition of these raw materials and the composition based on oxides. Both the raw material A and the raw material B are raw materials that are easily commercially available.

Table 1 Raw material A (rare earth oxide) Raw material B (rare earth carbonate) Loss on ignition (%) 0.6 30 Total rare earth oxide 99.1 69.5 (TREO; total rare earth oxide equivalent) CeO ₂ / TREO 60.0 58.0 La ₂ O ₃ / TREO 34.5 27.9 Pr ₆ O ₁₁ / TREO 4.5 7.6 Nd ₂ O ₃ / TREO 1.0 6.7 F 0.2 <0.1 CaO 0.1 0.05 * BaO 0.2 0.01 * P ₂ O ₅ 0.02 0.03 * SiO ₂ 0.01 Fe 0.01 * Indicates the values of Ca, Ba and P . (Unit:% by weight)

Here, the ignition loss in Table 1 is 10
When the dried raw material is heated at 1000 ° C for 1 hour,
Is the percentage of weight loss, which is measured as follows.
It was First, weigh the crucible with a constant weight of 0.1 mg.
It was measured until it fell off. In addition, each raw material is heated to 105 ° C
It was heated for 1 hour and dried sufficiently to obtain a raw material sample. So
Then, put each raw material sample in the crucible and weigh its weight.
Was measured to the order of 0.1 mg. This crucible is an electric furnace
Then, the temperature was raised gradually and ignited. 1 at 1000 ° C
After heating for a long time, quickly transfer the crucible to a desiccator.
And let it cool. After allowing to cool, remove it from the desiccator and
The amount was measured to the nearest 0.1 mg. Based on this measurement result
And the ignition loss of each raw material sample
Calculated. B = (W₁-W_Two) / (W₁-W_Three) X 100 [Where B: loss on ignition (%), W₁: With sample before ignition
Crucible weight (g), W _Two: Weight of sample and crucible after ignition
Amount (g), W_Three: Crucible weight]

Next, the above raw materials A and B were appropriately mixed and adjusted so that the ignition loss was as shown in Table 2 to obtain a composite raw material corresponding to each ignition loss. Specifically, the raw material A and the raw material B were weighed and mixed so that the weight ratio satisfying the following formula was obtained. The composite raw material thus obtained is the raw material targeted by the present invention. _{B = B A × W A /} (W A + W B) + B B × W B
/ (W _A + W _B ) [B; target loss on ignition, B _A ; loss on ignition of raw material A,
B _B; raw material B ignition loss, W _A; the dry weight of the raw materials A,
W _B ; dry weight of raw material B]

A cerium-based abrasive was manufactured using the obtained composite raw material. First, the composite raw material was pulverized by a wet ball mill to obtain a powder having an average particle size of 1.0 μm. This powder was treated with a mineral acid (hydrochloric acid having a concentration of 1N) and then treated with a 15 g / L ammonium fluoride aqueous solution to obtain a slurry.
The slurry was filtered and dried to obtain a dry cake. After roasting the obtained cake in an electric furnace at 920 ° C. for 2 hours,
I let it cool. Further, this was crushed and classified to obtain a cerium-based abrasive of the present invention.

Next, the obtained abrasive was dispersed in water to obtain a slurry having a concentration of 10% by weight. This slurry-like polishing liquid was used to polish a 65 mmφ flat panel glass at a polishing pressure of 15.7 kg / cm ² with a high-speed polishing machine. For the glass surface after polishing, the polishing value was measured and scratches were evaluated.

For comparison, the abrasives were manufactured and evaluated in the same manner as above when the raw material A alone was used as the raw material and the raw material B alone was used as the raw material.

Measurement of Polishing Value The weight of the flat panel glass before polishing was measured in advance, and the weight of the flat panel glass after polishing was measured to calculate the weight reduction amount due to polishing. Then, the weight loss due to polishing when the loss on ignition is 30% is 1
The amount of weight loss due to polishing in each loss on ignition was converted into a relative value to obtain a polishing value. The results are shown in Table 2.

Evaluation of Scratches The surface of the glass for flat panel after polishing was irradiated with a halogen lamp having a light source of 300,000 lux and evaluated by a reflection method. Specifically, the evaluation was made by a deduction system in which 100 points were set as a perfect score and a predetermined number of points were reduced according to the degree and number of scratches. The results are shown in Table 2.

Comprehensive Evaluation Based on the above-mentioned polishing value and the result of the scratch evaluation, comprehensive evaluation was carried out in the following three grades of A, B and C. The results are shown in Table 2. Evaluation A: Abrasive value of 107 or more and scratch evaluation of 95 or more Evaluation B: Abrasive value of 102 or more and scratch evaluation of 90 or more, which does not correspond to Evaluation A Evaluation C: Abrasive value of less than 102 or scratch However, the present invention is not limited to this evaluation standard.

Table 2 Ignition loss Polishing value Scratch evaluation Overall evaluation (%) 0.6 115 115 B 2 114 91 B 3 113 91 91 B 5 110 96 A 7 110 110 98 A 10 110 95 A 20 20 110 98 A 25 110 97 A 30 100 97 C

Example 2 As a raw material, a cerium-based rare earth carbonate (raw material B) shown in Table 1 was prepared. This raw material B was calcined at the predetermined temperature and time shown in Table 3. By this calcination, a part or all of the cerium carbonate in the raw material B was changed to cerium oxide to adjust the ignition loss of the calcined product. The composite raw material thus obtained is the raw material targeted by the present invention. Here, a part of the obtained raw material powder was heated at 1000 ° C. for 1 hour, and the weight loss was measured according to JIS-K-0067 (1992) to measure the loss on ignition. Using each of the raw materials thus obtained, a cerium-based abrasive was manufactured in the same manner as in Example 1, and the polishing value was measured and scratches were evaluated.
And a comprehensive evaluation was performed. The results are shown in Table 3.

Table 3 Loss on ignition Calcining temperature Calcining time Abrasive value Scratch evaluation Overall evaluation (%) (° C.) (hour) 0.1 1000 2 120 88 C 0.6 1000 1 115 115 90 B 2 1000 0. 7 114 91 B 3 1000 0.5 114 114 91 B 5 400 10 111 95 A 7 400 4 111 96 A 9 400 2 109 98 A 19 400 1 111 99 A 30 0 0 100 98 C

[0050]

As described above, according to the present invention,
It is possible to manufacture a cerium-based abrasive having excellent polishing power and polishing accuracy and its raw material with high productivity and low cost.

─────────────────────────────────────────────────── ─── Continued Front Page (56) References JP-A-8-134435 (JP, A) JP-A-10-106991 (JP, A) JP-A-10-106989 (JP, A) JP-A-9- 183966 (JP, A) Japanese Patent Publication 6-60014 (JP, B2) International Publication 01/88056 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09K 3/14 C01F 17 / 00 B24B 37/00-37/04 H01L 21/304

Claims (11)

(57) [Claims] 1. A raw material used for the production of a cerium-based abrasive, which comprises cerium-based rare earth carbonate and cerium-based rare earth oxide as main components, and has an ignition loss when heated at 1000 ° C. for 1 hour. Is 0.5 to 25% on a dry weight basis, a raw material for a cerium-based abrasive. 2. The raw material for cerium-based abrasive according to claim 1, wherein the loss on ignition is 5 to 25%. 3. A cerium-based rare earth carbonate and a cerium-based rare earth oxide are prepared, and the loss on ignition when the raw material is heated at 1000 ° C. for 1 hour is 0.5 to 25% on a dry weight basis. A method for producing a raw material for a cerium-based abrasive, which comprises mixing the raw materials at various weight ratios to obtain a composite raw material. 4. A cerium-based rare earth carbonate and a cerium-based rare earth carbonate are prepared by calcining the raw material and converting part of the raw material into a cerium-based rare earth oxide. A method for obtaining a composite raw material comprising the following: a calcination temperature and a calcination time during the calcination, wherein the ignition loss when the raw material after the calcination is heated at 1000 ° C. for 1 hour is on a dry weight basis. A method for producing a raw material for a cerium-based abrasive, which comprises adjusting the content to be 0.5 to 25%. 5. The method for producing a raw material for a cerium-based abrasive according to claim 3, wherein the loss on ignition is 5 to 25%. 6. A raw material according to claim 1 or 2, or a raw material produced by the method according to any one of claims 3 to 5, is prepared, and the raw material is slurried and / or wet-milled. A method for producing a cerium-based abrasive, which comprises filtering, drying and roasting. 7. The method for producing a cerium-based abrasive according to claim 6, wherein the raw material is treated with a mineral acid after the slurrying and / or the wet grinding and before the filtration. 8. The cerium-based abrasive according to claim 6, wherein the raw material is treated with ammonium fluoride and / or hydrofluoric acid after the slurrying and / or the wet grinding and before the filtration. Manufacturing method. 9. The method for producing a cerium-based abrasive according to claim 7, wherein the raw material is treated with ammonium fluoride and / or hydrofluoric acid after the treatment with the mineral acid and before the filtration. 10. A cerium-based abrasive produced by the method according to claim 6. 11. A cerium-based abrasive produced by using the raw material according to claim 1 or 2.