JP2000061917A - Ito molding and manufacture thereof and manufacture of ito sintered body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide moldings whose molding density is uniform by molding slurry consisting of indium oxide and tin oxide by casting above a specific pressure value with the help of a gypsum mold and setting the density irregularities below a specified value with an erosion region having a heavily tall shape. SOLUTION: It is possible to obtain ITO moldings with 58% or more molding density by making the specific surface area of indium oxide 3-8 m2/g through a temporary burning treatment. In this ease, a cold static water pressure pressing work is not required and the slurry pressure to be applied is 3 kg/cm2 or more to obtain the moldings with 1.5% or less density irregularities. The gypsum mold is preferably molded at 10 kg/cm2 or less slurry pressure from the viewpoint of its strength. The ITO moldings are dried at a room temperature. The ITO moldings with 98.5% or more relative density can be obtained by baking the moldings in an oxygen atmosphere. The baking temperature is preferably 1400-1600 deg.C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the production of an ITO target used for forming a transparent conductive film by a sputtering method.

[0002]

2. Description of the Related Art ITO thin films are widely used as transparent conductive films for liquid crystal displays and the like. As a method for forming this ITO thin film, a sputtering film forming method using an ITO sintered body as a target material is generally used.

In the sputtering method, plasma controlled by a magnet collides with a target,
There is a problem that the target is subject to erosion along the shape of the magnet, and the usage efficiency is low. In order to improve the use efficiency, for example, JP-A-57-185973 and JP-A-60-39158 disclose that a target in which the thickness of a portion where the target is severely worn is increased is used. As a method of manufacturing a target in which a region to be subjected to erosion (hereinafter, referred to as "erosion region") is thickened, a plurality of flat plate-shaped targets having different thicknesses are molded by a die pressing method, and the targets are baked and processed to form an ITO target. Then, there is a method in which it is attached to a support called a backing plate using solder or the like. However, in this method, since a plurality of targets are bonded together, it is possible that the seams of the targets may cause abnormal discharge.

A method of forming a molded body having a thick erosion region by a die pressing method is also conceivable. However, the density of the thick portion of the molded body is reduced, and the thick portion of the sintered body obtained by firing. In addition, defects such as color unevenness and density decrease occur.

A gypsum mold is used to mold a target having a thick erosion region by a slurry casting method in which a slurry is injected at normal pressure, and this is homogenized and consolidated by a cold isostatic press, followed by firing and processing. Then, there is a method for producing an ITO target (for example, Japanese Patent Laid-Open No. 1-29076).
4 publication). However, this method is costly because a cold isostatic press is used for consolidation.

There is a method of obtaining a molded body having a uniform molding density by a high-pressure slurry casting method using a high-strength material such as composite ceramics in a molding die (for example, Japanese Unexamined Patent Publication No. 8-32571).
No. 6). However, this is only a flat plate type molding example,
There is no example of molding in which the erosion region has a thick shape, and moreover, no specific explanation has been given that a good sintered body can be obtained by the numerical limitation on the uniformity of the molding density.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to inexpensively produce an ITO molded product having a thick erosion region and a uniform molding density by a slurry pressure slurry casting method in order to improve the use efficiency. To provide a way to do.

Another object of the present invention is to specify the uniformity of the molding density numerically, and by firing the ITO molded body within the specified value, there is no defect such as color unevenness or density decrease in the thick portion. It is to provide a method for manufacturing a density ITO sintered body.

[0009]

The inventors of the present invention measure the density of each part of the ITO molded body by cutting and sampling an ITO molded body having a thick erosion region obtained by a slurry casting method. Then, the molding conditions that the density unevenness becomes extremely small were found. Here, the density unevenness is defined as the percentage of the difference between the maximum value and the minimum value of the measured density of each part with respect to the average density. Furthermore, the density unevenness of the ITO molded body and the defects of the sintered body obtained by firing were examined,
The condition of the compact was found to obtain a good high-density sintered body having a thick and thick erosion region. The defects of the sintered body referred to here are irregularities in the thick portion (dents in the central portion), cracks, and color unevenness.

Further, the inventors of the present invention can obtain a dense ITO molded body by limiting the specific surface area of the indium oxide powder, and as a result, the ITO molded body has sufficient strength in the drying, degreasing and firing steps. It has been found that it is easy to handle and that a good high density sintered body can be obtained. The specific surface area here is a value measured by the BET method. The present invention has been completed based on these findings.

The present invention is characterized by the following items. (1) Slurry consisting of indium oxide and tin oxide, obtained by casting with a gypsum mold at a pressure of 3 kg / cm ² or more, has a thick erosion region, and density unevenness of 1.5% or less. Which is a molded body of ITO. (2) The erosion region has a thick shape and a dense shape obtained by casting a slurry of indium oxide and tin oxide at a pressure of 10 kg / cm ² or more using a mold made of resin and inorganic powder, IT with unevenness of 1.0% or less
O molded body. (3) Indium oxide having a specific surface area of 3 to 15 m ² / g,
It is obtained by slurry-molding tin oxide having a specific surface area of 1 to 8 m ² / g at a pressure of 3 kg / cm ² or more.
The erosion area has a thick shape, and uneven density is 1.
An ITO molded product having a relative density of 5% or less and a relative density of 50% or more. (4) and indium oxide having a specific surface area of 3 to 8 m ² / g, the pressure in the slurry comprising a specific surface area 1~8m ² / g tin oxide 3
The erosion area is thick and has a density variation of 1.5%, which is obtained by casting with sludge at a pressure of more than kg / cm ^2.
An ITO molded body having the following and a relative density of 58% or more.

(5) (a) Using indium oxide powder and tin oxide powder as raw materials, the specific surface area of indium oxide is 3 to 15 m ² / g and the specific surface area of tin oxide is 1 to 1 by calcination treatment.
Calcination step of raw material powder to be 8 m ² / g, (b) Put calcined indium oxide, tin oxide and ion-exchanged water into a resin pot, pulverize and mix with a dry ball mill, and then water,
A slurry is prepared by adding a dispersant and a binder with a wet ball mill so that the viscosity of the slurry is 200 cp or less and the concentration is 65% or more. (C) A defoaming agent is added to the prepared slurry to depressurize it. Degassing process,
(D) Molding step of molding an ITO molded body having a thick portion in the erosion region by a slurry casting method by pressurizing the degassed slurry with a molding die, and (e) an ITO molded body having a thick portion And a step of degreasing at 400 to 600 ° C. using a degreasing furnace after drying at room temperature.

In step (6) and (d), a gypsum mold is used as a mold and the slurry pressure is 3 kg / cm ^2.
The method for producing an ITO molded body according to (5) above, wherein the density is 10 kg / cm ² or less and the density unevenness of the ITO molded body having an erosion region having a thick portion is 1.5% or less. (7) In the step (d), a mold made of resin and inorganic powder is used as the molding mold, and the slurry pressurizing pressure is 10
The method for producing an ITO molded body according to the above (5), wherein the density of the ITO molded body is not less than 100 kg / cm ^{2 and not} more than 100 kg / cm ² , and the density unevenness of the ITO molded body having a thick portion in the erosion region is 1.0% or less. (8) I according to the above (6) or (7), characterized in that a molding die having pores of 1 to 10 μm is used on the surface of the plaster mold or the surface of the mold made of resin and inorganic powder.
Method for manufacturing TO molded body. (9) An ITO sintered body having a relative density of 98.5% or more, which is obtained by firing the ITO molded body obtained in (1) to (8) above at a temperature of 1400 to 1600 ° C. in an oxygen atmosphere. Production method.

The present invention will be described in detail below. The steps of manufacturing the ITO molded body and the ITO sintered body by the slurry casting method of the present invention are as shown in FIG. The respective manufacturing steps will be described below. (A) As the calcined raw material powder of the raw material powder, commercially available indium oxide powder and tin oxide powder can be used. When the raw material powder is fine and easily aggregates, fine particles may be grown by calcination. When the specific surface area of indium oxide is set to ³ to 15 m ² / g by the calcination treatment, an ITO molded body having a molding density of 50% or more can be obtained. When the specific surface area of indium oxide is set to ³ to 8 m ² / g by the calcination treatment, an ITO molded body having a molding density of 58% or more can be obtained. The specific surface area of tin oxide is preferably 1 to 8 m ² / g.

(B) Grinding with a ball mill, mixed Indium oxide, tin oxide, and ion-exchanged water are put into a resin pot and ground and mixed with a dry ball mill. The tin oxide content is preferably 5 to 10 wt%. Then water and dispersant,
A binder is added and a slurry is prepared by a wet ball mill. A container made of polyethylene, polypropylene, nylon, or the like can be used. Balls made of zirconia, resin, etc. can be used. As the dispersant, a polycarboxylic acid type can be used. As the binder, a wax emulsion type or an acrylic emulsion type can be used. The viscosity of the slurry is 200c
p or less is preferable, and the concentration of the slurry is preferably 65% or more.

(C) A defoaming agent is added to the degassed slurry and degassed under reduced pressure. As the defoaming agent, an amide type defoaming agent can be used.

(D) Slurry Slurry Casting Molding The degassed slurry is molded by a slurry casting method using a molding die made of gypsum or resin and inorganic powder, as shown in FIG.
A molded product having the shape shown in is obtained. Slurry casting is a method in which the slurry is poured into a mold under normal pressure or pressure and the water content in the slurry is removed through the porous surface of the mold to obtain a molded body. As the mold, a plaster mold or a mold made of resin and inorganic powder can be used.

As the gypsum mold, a mold having pores of 1 to 10 μm can be used. Since the plaster mold has excellent water absorption, it can be molded even if the slurry is injected at normal pressure.However, when molding a molded product with thick parts, cold molding is required to eliminate uneven density of the molded product. Hydrostatic pressing is essential. The present invention does not require cold isostatic pressing and does not require a slurry pressure of 3
Density unevenness is 1.5 by molding at more than kg / cm ^2.
% Or less of the molded product is obtained. Gypsum mold is 10 because of its strength
It is preferable to mold at a slurry pressure of kg / cm ² or less.

The mold made of resin and inorganic powder is
Since the water permeability is poor, it is preferable to pressurize the slurry for casting, and one having pores of 1 to 10 μm can be used. This mold has high strength and can inject the slurry at a high pressure to significantly shorten the molding time. Further, when a molded product having a thick portion is molded using this mold, a molded product having a density unevenness of 1.0% or less is obtained by molding at a slurry pressure of 10 kg / cm ² or more. Molding time can be shortened. A mold made of resin and inorganic powder is preferably used at a slurry pressure of 100 kg / cm ² or less from the viewpoint of leakage of slurry and cost of a mold fixing jig.

(E) Drying and degreasing of the molded body After the ITO molded body is dried at room temperature, residual moisture and binder are removed using a hot air circulation type degreasing furnace or the like. The degreasing temperature is preferably 400 to 600 ° C.

(F) Baking of ITO molded body IT having a relative density of 98.5% or more is obtained by firing the molded body in an oxygen atmosphere.
An O sintered body can be obtained. The firing temperature is 1400-1
600 ° C. is preferred.

[0022]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples. Example 1 2250 g of indium oxide powder having a specific surface area of 7.1 m ² / g
Then, 250 g of tin oxide powder having a specific surface area of 3.4 m ² / g, 75 g of ion-exchanged water and zirconia balls were put in a resin pot and mixed by a ball mill for 20 hours. Next, add 450 g of ion-exchanged water and 20 g of polycarboxylic acid-based dispersant, and add 1
Mix in ball mill for hours. After 1 hour, 25 g of a wax-based binder was added and ball mill mixing was performed for 19 hours. 1.3 g of an amide defoaming agent was added to the slurry and degassing under reduced pressure was performed. The concentration of this slurry was 81%.

The definition of the slurry concentration is as follows. Slurry concentration (%) = solute weight / (solute weight + solvent weight) × 100 Next, using a gypsum mold, slurry casting was performed under the conditions of a slurry pressure of 4.0 kg / m ² and a molding time of 60 minutes, and a molding size of 2
An ITO molded body of 45 × 245 × 11t (5t) was obtained.
The molded body was dried at room temperature and then degreased at 600 ° C. for 3 hours. The molded body is cut at the position shown in FIG. 3 to obtain a flat plate (5t).
Part, tapered part (5.11t part), thick part (1
Samples were obtained by sampling from the 1t portion) to a size of about 20 mm square. 60 or more samples were sampled from one molded body.

Next, the surface of the sampled sample was cleaned and the mass was measured. Further, the sample was immersed in oil for waterproofing, and then the oil was wiped lightly, and the reading of the balance when the sample was suspended in water with a wire or the like was measured to obtain the molding density.

The calculation method of the molding density is according to the equation 1.

[Formula 1] However, D: Molding density (%) A: Mass of sample (g) B: Mass of waterproofed sample (g) C: Reading of balance when suspending waterproofed sample in water (g) ρ: Test Density of water at temperature (g / cm ³ ) The true density of ITO was 7.15 (g / cm ³ ), and the density unevenness was determined from the molding density of each sample.

The calculation method of the density unevenness is based on Equation 2.

[Formula 2] However, ΔD: Density unevenness (%) D _max : Molding density maximum value (%) D _min : Molding density minimum value (%) D _ave : Molding density average value (%)

The measurement results of the molding density and the density unevenness are shown in Table 1.
Shown in. ½ of the degreased compact in oxygen atmosphere
It was baked at 50 ° C. for 8 hours to obtain an ITO sintered body. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

The method for calculating the firing density is as follows. Density (%) = weight / volume / 7.15 × 100 The sampling method of the sample when measuring the molding density distribution is shown in FIG. The molded body is cut in half in the direction of the long axis (L), and cut on one side into 1 to 6 parts according to thickness.

[0029] is molded in the same manner as in Example 1 except that the molded inclusive mud漿鋳using tin oxide powder of the indium oxide powder and a specific surface area of 3.2 m ² / g of Example 2 specific surface area 14.7 m ² / g, The molding density and the density unevenness were measured, and then firing was performed. Table 1 shows the measurement results of the molding density and the density unevenness. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

[0030] Using the tin oxide powder of the indium oxide powder and a specific surface area of 3.2 m ² / g Example 3 specific surface area of 3.2 m ² / g, the slurry pressure 4.
Molding was performed in the same manner as in Example 1 except that the slurry was cast and molded at 0 kg / cm ² and the molding time was 60 minutes, and the molding density and the density unevenness were measured, and firing was performed. Measurement results of molding density and density unevenness
It shows in Table 1. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

Example 4 5400 g of indium oxide powder having a specific surface area of 6.8 m ² / g
Then, 600 g of tin oxide powder having a specific surface area of 2.5 m ² / g, 180 g of ion-exchanged water and zirconia balls were put in a resin pot and mixed by a ball mill for 20 hours. Next, add 1080 g of ion-exchanged water and 48 g of polycarboxylic acid type dispersant, and add 1
Ball mill mixed for hours. After 1 hour, 60 g of a wax binder was added and ball mill mixing was performed for 19 hours.
The slurry was degassed under reduced pressure by adding 3 g of an amide defoaming agent. The concentration of this slurry was 81%.

Next, using a mold made of resin and inorganic powder, slurry casting was carried out under the conditions of a slurry pressure of 4.0 kg / cm ² and a molding time of 60 minutes, and a molding size of 730 × 252 × 1.
A molded product of 1 t (5 t) mm was obtained. The molded body was dried at room temperature and then degreased at 600 ° C. for 3 hours. Example 1 after degreasing
The molding density and the density unevenness were determined by the same method as described above. Molding density,
Table 1 shows the measurement results of the density unevenness. The degreased compact was fired in the same manner as in Example 1. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

[0033] Using the tin oxide powder of the indium oxide powder and a specific surface area of 2.5 m ² / g in Example 5 specific surface area of 6.0 m ² / g, the slurry pressure 1
Molding was carried out in the same manner as in Example 4 except that sludge casting was carried out at 0.0 kg / cm ² , and the molding density and density unevenness were measured and fired. Table 1 shows the measurement results of the molding density and the density unevenness.
Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

[0034] Using the tin oxide powder of the indium oxide powder and a specific surface area of 3.3 m ² / g of Example 6 specific surface area 6.5m ² / g, the slurry pressure 1
Molding was performed in the same manner as in Example 4 except that the slurry was cast at 5.0 kg / cm ² , and the molding density was measured and fired. IT
Table 2 shows the density of the O sintered body and the presence or absence of defects in the sintered body.

[0035] Using the tin oxide powder of the indium oxide powder and a specific surface area of 3.0 m ² / g Example 7 specific surface area 6.9 m ² / g, the slurry pressure 2
Molding was performed in the same manner as in Example 4 except that the slurry was cast at 2.0 kg / cm ² , and the molding density and density unevenness were measured and fired. Table 1 shows the measurement results of the molding density and the density unevenness. I
Table 2 shows the density of the TO sintered body and the presence or absence of defects in the sintered body.
Shown in.

[0036] Using the tin oxide powder of the indium oxide powder and a specific surface area of 3.1m ² / g of Comparative Example 1 specific surface area of 7.1 m ² / g, the slurry pressure 1.
Molding was performed in the same manner as in Example 1 except that the slurry was cast at 0 kg / cm ² , and the molding density and density unevenness were measured. Table 1 shows the measurement results of the molding density and the density unevenness. Irregularities were formed in the thick part of the ITO molded body, which required an increase in the grinding allowance.

[0037] Using the tin oxide powder of the indium oxide powder and a specific surface area of 2.5 m ² / g of Comparative Example 2 specific surface area of 6.8 m ² / g, the slurry pressure 1.
Molding was carried out in the same manner as in Example 1 except that sludge casting was carried out at 5 kg / cm ² for 230 minutes, and the molding density and density unevenness were measured. Table 1 shows the measurement results of the molding density and the density unevenness. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

[0038] Using the tin oxide powder of the indium oxide powder and a specific surface area of 3.0 m ² / g of Comparative Example 3 specific surface area of 6.9 m ² / g, the slurry pressure 1.
Molding was performed in the same manner as in Example 1 except that the slurry was cast at 5 kg / cm ² , and the molding density and density unevenness were measured. Table 1 shows the measurement results of the molding density and the density unevenness. Irregularities were formed in the thick part of the ITO molded body, which required an increase in the grinding allowance.

[0039] Using the tin oxide powder of the indium oxide powder and a specific surface area of 2.5 m ² / g in Comparative Example 4 specific surface area of 6.0 m ² / g, the slurry pressure 2.
Molding was performed in the same manner as in Example 1 except that the slurry was cast at 0 kg / cm ² , and the molding density and density unevenness were measured. Table 1 shows the measurement results of the molding density and the density unevenness. 25m for molded body
There were m cracks.

Comparative Example 5 5400 g of indium oxide powder having a specific surface area of 6.3 m ² / g
Then, 600 g of tin oxide powder having a specific surface area of 2.5 m ² / g, 180 g of ion-exchanged water and zirconia balls were put in a resin pot and mixed for 20 hours with a ball mill. Next, 1080 g of ion-exchanged water and 48 g of a polycarboxylic acid-based dispersant were added and mixed by a ball mill for 1 hour. After 1 hour, 60 g of a wax-based binder was added and ball mill mixing was performed for 19 hours. The slurry was degassed under reduced pressure by adding 3 g of an amide-based defoaming agent. The concentration of this slurry was 81%.

Next, using a plaster mold, the slurry pressure was 1.0 k.
Slurry casting was carried out under the conditions of g / cm ² and molding time of 90 minutes to obtain a molded product having a molding size of 715 × 250 × 11t (5t) mm. The molded body was dried at room temperature and then degreased at 600 ° C. for 3 hours. The molding density was 58.2%. The degreased compact is fired in an oxygen atmosphere at 1550 ° C. for 8 hours I
A TO sintered body was obtained. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

[0042] Using the tin oxide powder of the indium oxide powder and a specific surface area of 3.1m ² / g of Comparative Example 6 specific surface area of 7.1 m ² / g, the slurry pressure 1.
Molding was carried out in the same manner as in Example 1 except that sludge casting was carried out at 0 kg / cm ² and molding time of 50 minutes, the molding density was measured, and firing was carried out. The molding density was 59.4%. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

[0043] Using the tin oxide powder of the indium oxide powder and a specific surface area of 3.0 m ² / g of Comparative Example 7 specific surface area of 6.4 m ² / g, the slurry pressure 2.
Molding was carried out in the same manner as in Example 1 except that sludge casting was carried out at 0 kg / cm ² and molding time of 90 minutes, the molding density was measured, and firing was carried out. The molding density was 57.8%. Table 2 shows the density of the ITO sintered body and the presence or absence of defects in the sintered body.

Table 1 shows the values of slurry pressure, molding time, molding density and density unevenness during molding. Slurry pressure 3kg /
When molded with a cm ² or more, a very uniform molded body having a density unevenness of 1.5% or less can be obtained. When a mold made of resin and inorganic powder is used and molded at a slurry pressure of 10 kg / cm ² or more, a molded product having a density unevenness of 1.0% or less is obtained, and there is an advantage that the molding time can be shortened.

A slurry composed of indium oxide having a specific surface area of 3 to 15 m ² / g and tin oxide was applied with a slurry pressure of 3 kg /
By sludge casting at cm ² or more, a molded product having a thick erosion region, density unevenness of 1.5% or less, and relative density of 50% or more can be obtained. Further, by injecting a slurry of indium oxide having a specific surface area of 3 to 8 m ² / g and tin oxide at a slurry pressure of 3 kg / cm ² or more, the erosion region has a thick shape and density unevenness is 1 A molded product having a relative density of not more than 0.5% and a relative density of not less than 58% is obtained.

Table 2 shows the relationship between the slurry pressure, the firing density, and the defects after firing. A molded product molded with a slurry pressure of 1 to ² kg / cm ² and having a density unevenness of 1.8% or more is liable to cause color unevenness on the surface, unevenness of thick portions, cracks and the like due to firing. In the case of a molded body having a density unevenness of 1.0% or less formed by a slurry pressure of 3 kg / cm ² or more, surface unevenness of color,
No defects such as unevenness and cracks in the thick portion occur.

FIG. 4 shows the relationship between the slurry pressure measured in Examples and Comparative Examples and the density unevenness of the molded body.

The density distribution of the molded body is shown in FIGS. 5 and 6. FIG. 5 shows the relationship between the shape and the molding density of a molded body molded at a slurry pressure of 1.5 kg / cm ² . In the case of molding with a slurry pressure of 1.5 kg / cm ² , dehydration of the thick portion becomes insufficient and the molding density becomes low. In a portion where the molding density is low, the shrinkage rate due to firing is large, and the firing density is also low, so unevenness and uneven color are likely to occur. Further, the density variation (standard deviation) is large on the end face and the thick portion of the molded body, and cracks are likely to occur due to the difference in shrinkage during firing.

FIG. 6 shows the relationship between the thickness shape and the molding density of a molded body molded at a slurry pressure of 22 kg / cm ² . In the case of molding at a slurry pressure of 22 kg / cm ² , the high density portion is sufficiently dehydrated, so that the molding density becomes substantially uniform regardless of the thickness. With such a compact, it is possible to obtain a good sintered body that has no difference in shrinkage due to firing and uneven density and has no defects. The relationship between the shape and the molding density of the molded body molded at a slurry pressure of 4 kg / cm ² or more has the same result as in FIG.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

According to the present invention, by limiting the specific surface area of the indium oxide powder in the slurry casting method and selecting the slurry pressure within an appropriate range, cold isostatic pressing is not required and the erosion area can be thickened. It is possible to obtain an ITO molded body having a heightened shape with small density unevenness and no unevenness in the thick portion. A good high density sintered body can be obtained by firing this ITO molded body in an oxygen atmosphere.

[0053]

[Brief description of drawings]

FIG. 1 is an explanatory diagram relating to a manufacturing process of an ITO target by a pressure casting method according to the present invention and sampling of a density measurement sample.

FIG. 2 is a diagram illustrating the shape of a molded product obtained by the sludge casting method of the present invention.

FIG. 3 is a diagram showing a sampling method of a sample when measuring a molding density distribution.

FIG. 4 is a diagram showing a relationship between slurry pressure and density unevenness of a molded body.

FIG. 5 is a diagram showing the relationship between the thickness shape and the molding density when molded under a slurry pressure of 1 to ² kg / cm ² , using the data of Comparative Example 2.

FIG. 6 is a diagram showing the relationship between the thickness profile and the molding density when molded at a slurry pressure of 4 kg / cm ² or more, using the data of Example 7.

[Explanation of symbols]

Diagonal line Thick part Horizontal line Flat plate part L major axis length W Short axis length T1 Thickness High part thickness T2 flat plate thickness

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4G030 AA34 AA39 BA02 BA15 CA07                       CA08 GA08 GA09 GA14 GA16                       GA18 GA20 GA25 GA27 GA33                       PA21                 4G052 CA05 CB14 CC02 CC05 CC15                 4K029 BA45 BA47 BC09 DC05 DC09                       DC12                 5G323 BA02 BB06 BC01

Claims (9)

[Claims] 1. An erosion region having a thick shape and a density unevenness of 1.5, which is obtained by molding a slurry of indium oxide and tin oxide at a pressure of 3 kg / cm ² or more using a gypsum mold. % Or less I
TO molded body. 2. An erosion region having a thick shape obtained by casting a slurry of indium oxide and tin oxide at a pressure of 10 kg / cm ² or more using a mold made of resin and inorganic powder, An ITO molded product having a density unevenness of 1.0% or less. And indium oxide wherein a specific surface area 3~15m ² / g, obtained by molding inclusive mud漿鋳at a pressure 3 kg / cm ² or more slurry comprising tin oxide having a specific surface area 1~8m ² / g, the erosion region Has a thick shape and has an uneven density of 1.5% or less and a relative density of 50% or more. And indium oxide wherein a specific surface area of 3 to 8 m ² / g, obtained by molding inclusive mud漿鋳at a pressure 3 kg / cm ² or more slurry comprising tin oxide having a specific surface area 1~8m ² / g, the erosion region Has a thick shape and has a density unevenness of 1.5% or less and a relative density of 58% or more. 5. (a) Indium oxide powder and tin oxide powder are used as raw materials, and the specific surface area of indium oxide is 3 to 15 m ^2.
/ G, a calcination step of the raw material powder for calcination so that the specific surface area of tin oxide is 1 to 8 m ² / g, (b) The calcined indium oxide, tin oxide, and ion-exchanged water are put in a resin pot and dried. Grind and mix with a ball mill, and then add water, a dispersant and a binder to prepare a slurry with a wet ball mill to adjust the viscosity of the slurry to 20.
0 cp or less, a step of preparing a slurry having a concentration of 65% or more, (c) a step of adding an antifoaming agent to the prepared slurry to degas it under pressure, and (d) adding the degassed slurry using a molding die. A molding step of molding an ITO molded body having a thick portion in an erosion region by a slurry casting method by pressure, and (e) 400 to 600 using a degreasing furnace after drying the ITO molded body having a thick portion at room temperature. A method for producing an ITO molded body, which comprises a step of degreasing at ℃. 6. A gypsum mold is used as a mold in the step (d), and the slurry pressure is 3 kg / cm ² or more.
The method for producing an ITO molded body according to claim 5, wherein the density is 0 kg / cm ² or less, and the density unevenness of the ITO molded body having an erosion region having a thick portion is 1.5% or less. 7. In the step (d), a mold made of resin and inorganic powder is used as a molding mold, the slurry pressure is 10 kg / cm ² or more and 100 kg / cm ² or less, and the erosion region is a thick portion. 6. The method for producing an ITO molded body according to claim 5, wherein the density unevenness of the ITO molded body having the above is 1.0% or less. 8. The mold according to claim 6, wherein a molding die having pores of 1 to 10 μm is used on the surface of the plaster mold or the surface of the mold made of resin and inorganic powder.
Method for manufacturing TO molded body. 9. Production of an ITO sintered body having a relative density of 98.5% or more, which comprises firing the ITO molded body obtained in any one of claims 1 to 8 at a temperature of 1400 to 1600 ° C. in an oxygen atmosphere. Method.