JP2017145158A - Colored zirconia sintered body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a purple zirconia sintered body which is suitable for industrial production.SOLUTION: In a zirconia sintered body containing complex oxide of cobalt and aluminum, erbium oxide, zinc oxide, aluminum oxide and zirconia, the total content of cobalt, aluminum and zinc is 5 wt% or less in terms of oxides, the weight ratio of zinc to aluminum is below 0.9 in terms of oxides.SELECTED DRAWING: None

Description

  The present invention relates to a zirconia sintered body containing a coloring component. More specifically, the present invention relates to a zirconia sintered body exhibiting a purple color tone.

  Since it has high mechanical strength and high aesthetics, colored zirconia sintered bodies are used for decorative members such as watch bands and accessories. Furthermore, recently, in addition to these uses, application to high-grade building materials, mechanical members such as various structural members, ceramic electronic members such as electronic component boards, exterior members such as mobile phones and mobile home appliances, and the like has been studied.

  As one of the colored zirconia sintered bodies, a colored zirconia sintered body that exhibits purple as an intermediate color tone from red to blue has been studied.

For example, it has been reported that any one of erbium oxide, europium oxide or holmium oxide and a zirconia sintered body containing a zirconia sintered body containing zinc oxide and aluminum oxide exhibit a purple color (Patent Document 1). Furthermore, it is disclosed that a zirconia-alumina composite oxide containing Nd ₂ O ₃ or CoO exhibits a light purple color (Patent Document 2).

_Further, the zirconia sintered body containing a V 2 _{O 5} and _Al 2 _{O 3} is disclosed to exhibit violet (Patent Document 3).

Further, it has been disclosed that ZrO ₂ containing erbium oxide and a stabilizer exhibits a light pink color (Patent Document 4).

International Publication No. 2009/157508 JP-A-01-234364 Japanese Patent Laid-Open No. 01-157462 JP 04-002658 A

  The zirconia sintered body disclosed in Patent Document 1 is a zirconia sintered body exhibiting a color tone close to gray, and exhibits a color tone different from so-called purple. Moreover, the zirconia sintered bodies of Patent Documents 2 and 3 also have a color tone close to gray, and can be produced only by HIP treatment. The sintered body that was not subjected to the HIP treatment exhibited a color tone significantly different from purple. Moreover, patent document 4 is a zirconia sintered compact which exhibits a pink color or a light pink color, and exhibits a color tone different from purple.

  An object of the present invention is to provide a zirconia sintered body exhibiting a purple color, which is suitable for industrial production.

  The present inventors have examined the above problems. As a result, a zirconia sintered body mainly containing a complex oxide of cobalt and aluminum and erbium oxide as a colorant and containing zinc and aluminum in a certain ratio exhibits a purple color tone. It was found that it can be obtained stably.

  That is, the present invention contains a composite oxide of cobalt and aluminum, erbium oxide, zinc oxide, aluminum oxide and zirconia, and the total content of cobalt, aluminum and zinc is 5% by weight or less in terms of oxide. There is a zirconia sintered body in which the weight ratio of zinc to aluminum is less than 0.9 in terms of oxide.

  Hereinafter, the zirconia sintered body of the present invention will be described.

  The zirconia sintered body of the present invention contains a complex oxide of cobalt and aluminum, zinc oxide, aluminum oxide, and erbium oxide (hereinafter also referred to as “colored oxide” individually or collectively). Cobalt, aluminum, zinc and erbium in the zirconia sintered body function as colorants. By containing these four different colored oxides, the zirconia sintered body of the present invention exhibits a purple color, and further a reddish and bluish purple color.

  In the zirconia sintered body of the present invention, the total content of the colored oxides may be 20% by weight or less, and further 15% by weight or less. It can be set as the colored oxide and content, and it can be set as the zirconia sintered compact which exhibits purple. In addition to this, the reproducibility of the color tone is enhanced in repeated production, particularly in production by repeated atmospheric pressure sintering. In order to clarify the coloration, the total content of the colored oxide is preferably 5% by weight or more, and more preferably 7% by weight or more.

In addition, content of the colored oxide in the zirconia sintered compact of this invention is a weight ratio of each colored oxide with respect to the weight of a zirconia sintered compact. Each colored oxide is a composite oxide of cobalt and aluminum, CoAl ₂ O ₄ , cobalt oxide is CoO, aluminum oxide is Al ₂ O ₃ , erbium oxide is Er ₂ O _3, and zinc oxide is ZnO. You can ask for.

  The zirconia sintered body of the present invention contains a composite oxide of cobalt and aluminum (hereinafter also referred to as “Co—Al composite oxide”). By containing the Co—Al composite oxide and erbium oxide, the zirconia sintered body of the present invention exhibits a purple color tone.

The Co—Al composite oxide is preferably a Co—Al composite oxide having a spinel structure, and more preferably cobalt aluminate (CoAl ₂ O ₄ ). Cobalt aluminate contains a certain proportion of cobalt and aluminum uniformly. As a result, the zirconia sintered body of the present invention exhibits a uniform color tone. On the other hand, in a zirconia sintered body containing cobalt oxide and aluminum oxide as respective oxides, the distribution of cobalt and aluminum in the sintered body tends to be non-uniform. As a result, color unevenness tends to occur in the sintered body. In particular, cobalt oxide as a simple substance exhibits a color tone different from that of the Co—Al composite oxide, and is likely to cause noticeable color unevenness. Therefore, it is preferable that the zirconia sintered body of the present invention does not contain cobalt oxide that does not form a complex oxide with aluminum, and further does not contain cobalt oxide, or even CoO and Co ₃ O ₄ .

The color tone of the zirconia sintered body of the present invention is mainly affected by the content of the Co—Al composite oxide and the content of erbium oxide. Therefore, the preferred content of the Co—Al composite oxide varies depending on the content of erbium oxide. The content of the Co—Al composite oxide is 0.01% by weight or more and 1% by weight or less, more preferably 0.01% by weight or more and 0.3% by weight or less when converted as an oxide (CoAl ₂ O ₄ ). Furthermore, it is 0.05 to 0.3 weight%.

  The zirconia sintered body of the present invention contains erbium oxide. By including the Co—Al composite oxide and erbium oxide, a purpleish color tone is exhibited. In addition, erbium oxide functions as a zirconia stabilizer. The content of erbium oxide is preferably 5% by weight or more, more preferably 7% by weight or more. Thereby, the zirconia sintered compact of this invention can exhibit bright purple. On the other hand, erbium oxide is preferably 15% by weight or less, more preferably 13% by weight or less, and even more preferably 9% by weight or less.

  Erbium oxide may be contained in a solid solution state or an oxide state in zirconia. Since color unevenness in the sintered body is less likely to occur, it is preferable that erbium oxide is in a solid solution state in zirconia, that is, zirconia is erbium oxide-containing zirconia.

  Whether or not erbium oxide is dissolved in zirconia can be confirmed by a powder X-ray diffraction (hereinafter referred to as “XRD”) pattern of the zirconia sintered body. That is, when erbium oxide is dissolved in zirconia, an independent XRD peak of erbium oxide is not confirmed in the XRD pattern.

The zirconia sintered body of the present invention contains aluminum oxide and zinc oxide. By containing aluminum oxide in addition to the Co-Al composite oxide and containing zinc oxide, it is possible to control the lightness L ^* and chromaticity b ^* of the zirconia sintered body of the present invention. A purple tone can be obtained with high reproducibility in repeated production by pressure sintering.

  Furthermore, in the zirconia sintered body of the present invention, the weight ratio of zinc to aluminum (hereinafter, also referred to as “Zn / Al ratio”) is less than 0.9 in terms of oxide, and further 0.88 or less. When the Zn / Al ratio is increased, the yellowish tone becomes too strong, and the blue tone becomes weak. Furthermore, if the Zn / Al ratio exceeds 1.2, the sintered body tends to break during sintering. In order to obtain a bright purple sintered body with good reproducibility, the Zn / Al ratio is preferably 0.15 or more, more preferably 0.19 or more. A preferable Zn / Al ratio range is 0.15 to less than 0.9, further 0.15 to 0.89, further 0.25 to 0.85, and further 0.35 to 0.00. 6 or less can be mentioned.

  The zinc oxide and aluminum oxide content of the zirconia sintered body of the present invention may be any content as long as the Zn / Al ratio is in the above range. The content of zinc oxide is 0.05% by weight or more and 1.2% by weight or less, and further 0.15% by weight or more and 1.05% by weight or less. The aluminum oxide content is 0.25 wt% or more and 2.0 wt% or less, more preferably 0.25 wt% or more and 1.50 wt% or less, and further 0.5 wt% or more, 1.5 wt% or less. It is mentioned that it is below wt%.

In the zirconia sintered body of the present invention, the total content of cobalt, aluminum and zinc (hereinafter also referred to as “colored metal amount”) is 5% by weight or less in terms of oxide. When the amount of the colored metal exceeds 5% by weight, the lightness L ^* becomes too low, and a sintered body having a light color tone cannot be obtained. The amount of the colored metal is preferably 4% by weight or less, more preferably 2.85% by weight or less. Furthermore, when the amount of the colored metal is 2.1% by weight or less, the lightness L ^* tends to be high, and the color tone of the sintered body tends to be bright. The amount of the colored metal may be 0.45% by weight or more, further 0.6% by weight or more.

The amount of the colored metal is a ratio of the total weight obtained by converting cobalt, aluminum and zinc into CoO, Al ₂ O ₃ and ZnO, respectively, with respect to the weight of the zirconia sintered body of the present invention.

  The zirconia sintered body of the present invention contains a colored oxide, and the balance is zirconia. The zirconia is preferably a stabilizer-containing zirconia.

  Zirconia may have a stabilizer content of 2.0 mol% or more and 5.0 mol% or less, further 3.1 mol% or more and 5.0 mol% or less, and further 3.1 mol% or more and 3.8 mol% or less. . By including the stabilizer in the above range, the zirconia in the sintered body becomes a single phase of tetragonal zirconia or zirconia having a main phase of tetragonal crystal. Thereby, the mechanical strength of the zirconia sintered body of the present invention becomes higher.

  The content (mol%) of the stabilizer in the zirconia sintered body of the present invention is the molar ratio of the stabilizer to the total of zirconia and the stabilizer in the zirconia sintered body, and is obtained by the following equation. Can do.

Stabilizer content (mol%)
= Stabilizer (mol) / {Stabilizer (mol) + Zirconia (mol)} × 100
In the above formula, the stabilizer is the number of moles in terms of oxide.

The stabilizer contained in zirconia contains at least erbium oxide.
The stabilizer preferably contains a substance other than erbium oxide that does not significantly affect the color tone of the sintered body, and includes yttrium oxide (Y ₂ O ₃ ), magnesium oxide (MgO), calcium oxide (CaO), and oxidation. More preferably, it contains at least one member selected from the group consisting of cerium (CeO ₂ ), and zirconia is particularly preferably zirconia containing erbium oxide and yttrium oxide.

When zirconia is zirconia containing erbium oxide and yttrium oxide as stabilizers, erbium oxide and yttrium oxide-containing zirconia, the erbium oxide content is preferably larger than the yttrium oxide content, and yttrium oxide The molar ratio of erbium oxide with respect to (hereinafter also referred to as “Er ₂ O ₃ / Y ₂ O ₃ ratio”) exceeds 1, more preferably 2.5 to 8.0, and still more preferably 3.0 to 6. It is preferably 0 or less, and more preferably 3.0 or more and 4.0 or less.

Although the zirconia sintered body of the present invention exhibits a purple color tone, L ^* , a ^* and b ^{* in} the L ^* a ^* b ^* color system (hereinafter referred to simply as “L ^* ”, “a ^* ” and “ Are also referred to as “b ^* ”.) Are 35 ≦ L ^* ≦ 60, 2 ≦ a ^* ≦ 20, and −60 ≦ b ^* ≦ −10, respectively.

More preferably, L ^* is from 39.5 to 63.4, a ^* is from 3.6 to 14.2, and b ^* is from −48.5 to −7.8. Furthermore, it is preferable that 9 ≦ a ^* ≦ 20 and −60 ≦ b ^* ≦ −40. Thereby, the color tone of the zirconia sintered body of the present invention tends to become a clearer blue-violet.

  The higher the strength of the zirconia sintered body of the present invention, the more uses for which it can be applied. Therefore, the zirconia sintered body of the present invention preferably has a three-point bending strength of 1100 MPa or more, and more preferably 1200 MPa or more. The three-point bending strength is 1200 MPa or more and 1350 MPa or less.

  Next, the manufacturing method of the zirconia sintered compact of this invention is demonstrated.

  The zirconia sintered body of the present invention is obtained by forming and sintering a composite oxide of cobalt and aluminum, zinc oxide, aluminum oxide, erbium oxide, and zirconia after mixing so as to satisfy the above composition. Can be manufactured.

  Furthermore, as a preferable production method of the zirconia sintered body of the present invention, a mixing step of mixing a composite oxide of cobalt and aluminum, zinc oxide and aluminum oxide, and zirconia containing erbium oxide, a forming step of forming the obtained mixture And the manufacturing method containing the sintering process which sinters the obtained molded object can be mentioned.

  In the mixing step, cobalt-aluminum complex oxide (Co-Al complex oxide), zinc oxide, aluminum oxide, and erbium oxide-containing zirconia are mixed. By mixing the erbium oxide-containing zirconia and the Co—Al composite oxide, erbium, cobalt and aluminum in the obtained zirconia sintered body are more uniformly distributed. Thereby, it becomes easy to become the sintered compact which shows purple coloration without a color nonuniformity more.

  The erbium oxide-containing zirconia is preferably erbium oxide solid solution zirconia. As more preferable erbium oxide solid solution zirconia, erbium oxide solid solution zirconia obtained by mixing and drying a hydrated zirconia sol aqueous solution and an erbium compound and calcining at 1000 ° C. or more and 1200 ° C. or less can be exemplified.

  Examples of the erbium compound include erbium oxide, hydrated erbium oxide, erbium oxide sol, erbium hydroxide, erbium chloride, and erbium nitrate, and at least one of erbium oxide and erbium chloride. it can.

  Further, when the hydrated zirconia sol aqueous solution and the erbium compound are mixed, a stabilizer other than erbium oxide or a precursor thereof may be mixed. Thereby, it can be set as the zirconia in which the erbium oxide and the stabilizer dissolved.

  As a stabilizer or a precursor thereof, at least one oxide, hydrated oxide, sol, hydroxide of the group consisting of yttrium (Y), magnesium (Mg), calcium (Ca), and cerium (Ce) , Chlorides, and nitrates.

  Since it is particularly preferred that the stabilizer other than erbium oxide is yttria, the stabilizer or precursor thereof is at least one of the group consisting of yttria, hydrated yttria, yttria sol, yttrium hydroxide, yttrium chloride, and yttrium nitrate. One kind, and at least one of yttria and yttrium chloride can be mentioned.

  The hydrated zirconia sol after mixing with the erbium compound and, if necessary, the stabilizer or precursor thereof may be appropriately dried and calcined.

  The Co—Al composite oxide, zinc oxide, and aluminum oxide are preferably mixed with erbium oxide-containing zirconia so that the composition of the zirconia sintered body of the present invention is obtained.

  The contents of the Co—Al composite oxide, zinc oxide, and aluminum oxide in the mixture are 0.01% by weight or more and 1% by weight or less for Co—Al composite oxide, and 0.05% by weight or more for zinc oxide. .2% by weight or less, and aluminum oxide is 0.25% by weight or more and 2.0% by weight or less.

  Furthermore, it is preferable to mix aluminum oxide and zinc oxide so that the Zn / Al ratio in the mixture is 0.15 or more and less than 0.9. The brightness of the zirconia sintered body obtained by this becomes high, and it becomes a sintered body which exhibits a clearer purple color.

  If the composition of the obtained mixture becomes uniform, the mixing method is arbitrary, and either wet mixing or dry mixing may be used. Since the resulting mixture becomes more uniform, the mixing is preferably wet mixing, and more preferably wet mixing using a ball mill.

  In the forming step, the mixture obtained in the mixing step is formed. The method is arbitrary as long as a molded body having a desired shape is obtained. Examples of the molding method include at least one selected from the group consisting of press molding, cold isostatic pressing, sheet molding, injection molding, and cast molding.

  In the sintering process, the molded body obtained in the molding process is sintered. Any method can be applied as the sintering method. From an industrial point of view, the sintering process is preferably a simple sintering method, and is preferably atmospheric pressure sintering. The normal pressure sintering is a method of sintering by simply heating without applying an external force to the compact during sintering.

  The sintering atmosphere may be any of an oxidizing atmosphere, an inert atmosphere, or a reducing atmosphere, but is preferably an oxidizing atmosphere, and more preferably in the air.

  The sintering temperature should just be 1300 degreeC or more and 1500 degrees C or less.

  In a production method including two or more sintering treatments such as HIP treatment after atmospheric pressure sintering, the color tone of the sintered body tends to change, and reproducibility tends to be low. Therefore, in the production method of the present invention, it is preferable that the heating to 900 ° C. or higher is only the sintering step, and the sintering step is atmospheric pressure sintering at 1400 ° C. or higher and 1500 ° C. or lower in the atmosphere. It is preferable not to have a step of heat-treating the sintered body to 900 ° C. or higher after the step. The zirconia sintered body of the present invention tends to have a high three-point bending strength of 1100 MPa or more even with such a sintering method.

  According to the present invention, it is possible to provide a zirconia sintered body exhibiting a purple color, which is suitable for industrial production.

  Furthermore, since the zirconia sintered body of the present invention exhibits a high aesthetic violet color and further a blue-violet color, it is not only used for known zirconia sintered bodies but also for applications that require decorative properties such as various exterior members. Can be used.

Powder X-ray diffraction pattern of the zirconia sintered body of Example 22

  Hereinafter, the present invention will be specifically described. However, the present invention is not limited to these examples.

(Density measurement)
The density of the sintered body sample was measured by the Archimedes method.
(Measurement of color tone)
As the color tone of the sintered body sample, color parameters L ^* , a ^* , and b ^* defined in JISZ8729 were measured. For the measurement of color tone, the surface of the sintered body was polished to a mirror surface. The color tone was measured at three points, and the average value was used as the color tone of each sample.
In addition, as a pretreatment, the surface of the sintered body sample was ground by 0.3 mm, and mirror polishing was performed until there were no grinding marks.
(Strength of sintered body)
The three-point bending strength of the sintered body sample was measured by a method based on JIS R1601.

Example 1
A hydrous zirconia sol was obtained by hydrolyzing the zirconium oxychloride aqueous solution. YCl ₃ and ErCl ₃ were added to the hydrated zirconia sol so that the Y ₂ O ₃ concentration was 3.0 mol% and the Er ₂ O ₃ concentration was 3.1 mol%.

The zirconia sol after the addition was dried at 180 ° C. and then calcined at 1150 ° C. for 2 hours to obtain a powder. The obtained powder was washed with distilled water and then dried at 110 ° C. to obtain zirconia powder containing 0.72 mol% Y ₂ O ₃ and 2.41 mol% Er ₂ O ₃ .
In the obtained zirconia powder, CoAl ₂ O ₄ was 0.1% by weight, ZnO was 0.45% by weight, and Al ₂ O ₃ was 0.75% by weight. ₂ O ₄ powder, ZnO powder and Al ₂ O ₃ powder were mixed.
Distilled water was added to the obtained mixed powder to obtain a slurry having a solid content concentration of 45% by weight. The slurry was pulverized and mixed by a ball mill using zirconia balls having a diameter of 10 mm. The pulverization and mixing were performed such that the particle size of the mixed powder was Dmax ≦ 5.5 μm.
After mixing, the slurry was dried and passed through an opening of 180 μm to obtain a raw material powder.

5 g of the raw material powder is put into a mold having a diameter of 25 mm, press-molded at a molding pressure of 98 MPa to form a molded body, and then sintered in the atmosphere at 1450 ° C., a heating rate of 100 ° C./hr, and holding for 2 hours. A zirconia sintered body of this example was obtained. The obtained zirconia sintered body had a density of 6.228 g / cm ³ . Table 1 shows the stabilizer content, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 2
The same method as in Example 1 except that the CoAl ₂ O ₄ powder was 0.30 wt%, the ZnO powder was 0.70 wt%, and the Al ₂ O ₃ powder was 0.75 wt%. Thus, a zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 3
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the ZnO powder was 0.45% by weight and the Al ₂ O ₃ powder was 0.50% by weight. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 4
The same method as in Example 1 except that the CoAl ₂ O ₄ powder was 0.20 wt%, the ZnO powder was 0.90 wt%, and the Al ₂ O ₃ powder was 1.50 wt%. Thus, a zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 5
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the Al ₂ O ₃ powder was 0.50% by weight. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 6
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the CoAl ₂ O ₄ powder was 0.05 wt% and the ZnO powder was 0.15 wt%. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 7
Example 1 except that the CoAl ₂ O ₄ powder was 0.20 wt%, the ZnO powder was 0.90 wt%, and the Al ₂ O ₃ powder was 1.00 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 8
A hydrous zirconia sol was obtained by hydrolyzing the zirconium oxychloride aqueous solution. A zirconia powder was obtained in the same manner as in Example 1 except that ErCl ₃ was added to the hydrated zirconia sol so that the Er ₂ O ₃ concentration was 4.66 mol%. The resulting zirconia powder contained 4.66 mol% Er ₂ O ₃ .
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the zirconia powder was used. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 9
A hydrous zirconia sol was obtained by hydrolyzing the zirconium oxychloride aqueous solution. YCl ₃ and ErCl ₃ were added to the hydrated zirconia sol so that the Y ₂ O ₃ concentration was 0.36 mol% and the Er ₂ O ₃ concentration was 2.77 mol%. The resulting zirconia powder contained 0.36 mol% Y ₂ O ₃ and 2.77 mol% Er ₂ O ₃ .
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the zirconia powder was used. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 10
Example 1 except that the CoAl ₂ O ₄ powder was 0.05 wt%, the ZnO powder was 0.15 wt%, and the Al ₂ O ₃ powder was 0.50 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 11
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the CoAl ₂ O ₄ powder was 0.05 wt% and the ZnO powder was 0.25 wt%. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 12
Similar to Example 1 except that the CoAl ₂ O ₄ powder was 0.20 wt%, the ZnO powder was 0.65 wt%, and the Al ₂ O ₃ powder was 1.50 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 13
Similar to Example 1 except that the CoAl ₂ O ₄ powder was 0.20 wt%, the ZnO powder was 0.75 wt%, and the Al ₂ O ₃ powder was 1.25 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 14
Example 1 except that the CoAl ₂ O ₄ powder was 0.05% by weight, the ZnO powder was 0.85% by weight, and the Al ₂ O ₃ powder was 1.25% by weight. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 15
A hydrous zirconia sol was obtained by hydrolyzing the zirconium oxychloride aqueous solution. A zirconia powder was obtained in the same manner as in Example 1 except that ErCl ₃ was added to the hydrated zirconia sol so that the Er ₂ O ₃ concentration was 3.16 mol%. The resulting zirconia powder contained 3.16 mol% Er ₂ O ₃ .

The zirconia powder was used, the CoAl ₂ O ₄ powder was 0.20 wt%, the ZnO powder was 0.75 wt%, and the Al ₂ O ₃ powder was 1.25 wt%. Except for this, the zirconia sintered body of this example was obtained in the same manner as in Example 1. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 16
Example 1 except that the CoAl ₂ O ₄ powder was 0.30 wt%, the ZnO powder was 1.00 wt%, and the Al ₂ O ₃ powder was 1.50 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 17
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the CoAl ₂ O ₄ powder was 0.05% by weight and the Al ₂ O ₃ powder was 1.00% by weight. It was. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 18
Example 1 except that the CoAl ₂ O ₄ powder was 0.05 wt%, the ZnO powder was 0.85 wt%, and the Al ₂ O ₃ powder was 1.00 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 19
Example 1 except that the CoAl ₂ O ₄ powder was 0.30 wt%, the ZnO powder was 0.95 wt%, and the Al ₂ O ₃ powder was 1.50 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 20
Example 1 except that the CoAl ₂ O ₄ powder was 0.05% by weight, the ZnO powder was 0.25% by weight, and the Al ₂ O ₃ powder was 0.50% by weight. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 21
Example 1 except that the CoAl ₂ O ₄ powder was 0.20 wt%, the ZnO powder was 0.70 wt%, and the Al ₂ O ₃ powder was 1.25 wt%. Thus, the zirconia sintered body of this example was obtained. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results.

Example 22
A zirconia sintered body of this example was obtained in the same manner as in Example 1 except that the erbium oxide-containing zirconia powder obtained by the same method as in Example 15 was used. Table 1 shows the stabilizer content of the obtained zirconia sintered body, Table 2 shows the composition of the sintered body, and Table 3 shows the evaluation results. The three-point bending strength of the zirconia sintered body of this example was 1240 MPa. The XRD pattern of the zirconia sintered body of the present example is shown in FIG. Since there is no erbium oxide peak, it can be confirmed that erbium oxide is dissolved in zirconia.

Comparative Example 1
A hydrous zirconia sol was obtained by hydrolyzing the zirconium oxychloride aqueous solution. A zirconia powder was obtained in the same manner as in Example 1 except that ErCl ₃ was added to the hydrated zirconia sol so that the Er ₂ O ₃ concentration was 3.1 mol%. The resulting zirconia powder contained 3.1 mol% Er ₂ O ₃ .
Except that the zirconia powder was used, the CoAl ₂ O ₄ powder was 0.10 wt%, the ZnO powder was not mixed, and the Al ₂ O ₃ powder was 0.15 wt%. A zirconia sintered body of this comparative example was obtained in the same manner as in Example 1. Table 4 shows the stabilizer content of the obtained zirconia sintered body, Table 5 shows the composition of the sintered body, and Table 6 shows the evaluation results.
The zirconia sintered body of this comparative example did not contain zinc, and its color tone was reddish black.

Comparative Example 2
A hydrous zirconia sol was obtained by hydrolyzing the zirconium oxychloride aqueous solution. YCl ₃ and ErCl ₃ were added to the hydrated zirconia sol so that the Y ₂ O ₃ concentration was 0.23 mol% and the Er ₂ O ₃ concentration was 3.00 mol%. The resulting zirconia powder contained 0.23 mol% Y ₂ O ₃ and 3.00 mol% Er ₂ O ₃ .
The zirconia powder was used, the CoAl ₂ O ₄ powder was 1.50% by weight, the ZnO powder was 3.00% by weight, and the Al ₂ O ₃ powder was 3.00% by weight. Except for this, the zirconia sintered body of this comparative example was obtained in the same manner as in Example 1. Table 4 shows the stabilizer content of the obtained zirconia sintered body, Table 5 shows the composition of the sintered body, and Table 6 shows the evaluation results.
Since the zirconia sintered body of this comparative example contained a large amount of colored metal, the color tone was dark blue.

Comparative Example 3
Example 1 except that the CoAl ₂ O ₄ powder was 0.05% by weight, the ZnO powder was 0.55% by weight, and the Al ₂ O ₃ powder was 0.50% by weight. Thus, a zirconia sintered body of this comparative example was obtained. Table 4 shows the stabilizer content of the obtained zirconia sintered body, Table 5 shows the composition of the sintered body, and Table 6 shows the evaluation results.
Since the zirconia sintered body of this comparative example contained a large amount of colored metal, the color tone was slightly bluish red.

Comparative Example 4
A hydrous zirconia sol was obtained by hydrolyzing the zirconium oxychloride aqueous solution. YCl ₃ and ErCl ₃ were added to the hydrated zirconia sol so that the Y ₂ O ₃ concentration was 0.41 mol% and the Er ₂ O ₃ concentration was 3.15 mol%. The resulting zirconia powder contained 0.41 mol% Y ₂ O ₃ and 3.15 mol%) Er ₂ O ₃ .
The zirconia powder was used, the CoAl ₂ O ₄ powder was 2.50% by weight, the ZnO powder was 4.0% by weight, and the Al ₂ O ₃ powder was 6.0% by weight. Except for this, the zirconia sintered body of this comparative example was obtained in the same manner as in Example 1. Table 4 shows the stabilizer content of the obtained zirconia sintered body, Table 5 shows the composition of the sintered body, and Table 6 shows the evaluation results.
Since the zirconia sintered body of this comparative example contained a large amount of colored metal, its color tone was bright blue.

Comparative Example 5
Example 1 except that the CoAl ₂ O ₄ powder was 0.10 wt%, the ZnO powder was 0.60 wt%, and the Al ₂ O ₃ powder was 0.25 wt%. Sintered by various methods. However, the zirconia sintered body was cracked by sintering, and the color tone could not be evaluated. Table 4 shows the stabilizer content of the obtained zirconia sintered body and Table 5 shows the composition of the sintered body.

  The zirconia sintered body of the present invention is a high-density and purple-colored sintered body excellent in aesthetics that exhibits a stable hue even when it is deteriorated by use, and is a high-quality treasure that is not damaged. It can be used for various members such as ornaments and decorative members, for example, watch parts and exterior parts of portable electronic devices.

Claims (6)

  It contains a complex oxide of cobalt and aluminum, erbium oxide, zinc oxide, aluminum oxide and zirconia, and the total content of cobalt, aluminum and zinc is 5% by weight or less in terms of oxide, A zirconia sintered body having a weight ratio of less than 0.9 in terms of oxide.   The zirconia sintered body according to claim 1, wherein the total content of the composite oxide of cobalt and aluminum, zinc oxide, aluminum oxide and erbium oxide is 20% by weight or less.   The zirconia sintered body according to claim 1 or 2, wherein the zirconia stabilizer content is 2.0 mol% or more and 5.0 mol% or less. L ^* a ^* b ^{* L} in color system *, claim ^{a *} and ^{b *, respectively, 35 ≦ L * ≦ 60,2 ≦} a * ≦ 20, and a -60 ≦ ^{b *} ≦ -10 The zirconia sintered body according to any one of 1 to 3.   A mixing step of mixing a composite oxide of cobalt and aluminum, zinc oxide and aluminum oxide, and erbium oxide-containing zirconia, a forming step of forming the obtained mixture, and a sintering step of sintering the obtained formed body The manufacturing method of the zirconia sintered compact as described in any one of Claims 1 thru | or 4 containing these.   The manufacturing method according to claim 5, wherein the sintering step is atmospheric pressure sintering.

Images