JP2946343B2 - High strength color zirconia sintered body and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a color zirconia sintered body, and more particularly to a pink, low-temperature sinterable zirconia sintered body.

[Problems to be solved by conventional technology and invention]

Zirconia sintered bodies, especially tetragonal zirconia sintered bodies, are being applied to household goods such as blades and sports goods such as golf shoes spikes due to their high strength and beautiful surface gloss after mirror polishing. Applications to decorative components such as cases and accessories are also expanding. In order to cope with such expanding use, color zirconia having various colors is demanded. Red and pink colors are preferred, especially for women's products, but zirconia in these colors has been rarely reported. Usually, as a method for producing color zirconia, a method of adding a pigment (mainly an oxide) to stabilized zirconia, mixing and sintering (Japanese Patent Application Laid-Open No. 59-50050), or a method of adding a small amount of a colorant ( (Mainly rare earth) solid solution by coprecipitation method etc.
-59571) is known as a method for producing powder.

However, in the method of mixing the above-mentioned color pigments, the addition amount is relatively large, so that the sintering is difficult, and the properties of the sintered body, particularly the mechanical strength is reduced. However, there still remains a problem that it is difficult to produce clear colors because of the difficulty in producing the color. Further, the method in which a small amount of a colorant is dissolved in a solid solution by the coprecipitation method has a disadvantage that the color density is low and the color is indistinct as color zirconia and the use thereof is limited. In addition, there is no particular improvement in the sinterability of these two methods, and the pigment addition method has a serious problem that the sinterability is rather lowered and the strength is lowered. Therefore, sintering was not easy in the pigment addition method, such as high-temperature and high-pressure sintering (HIP treatment).

An object of the present invention is to solve the drawbacks of the conventional colored zirconia, and in particular, to obtain a pink colored zirconia with high strength and a clear color.

[Means for solving the problem]

The color zirconia sintered body according to the present invention is composed of ZrO ₂ containing a stabilizer and a small amount of a coloring agent and a sintering aid, and has a low sintering temperature, a clear color tone, and a decrease in mechanical strength. There is no pink zirconia sintered body.

An erbium (Er) compound is used as a coloring agent.
When added and solid-dissolved in zirconia by a coprecipitation method, an oxalate method, an evaporation to dryness method, a hydrolysis method, etc. together with a stabilizer, water-soluble compounds, specifically chlorides, nitrates, etc. can be used, In addition, when added to ZrO ₂ powder already containing a stabilizer, oxides, acetates, carbonates, and the like can be used in addition to the aqueous solution compound, and the amount of the oxide in the sintered body is stabilized. It is added so as to be 0.5 to 2.0 mol% with respect to ZrO ₂ containing the agent.

Although a Zn compound is used as a sintering aid, it is necessary to limit the type of the compound as long as the compound becomes an oxide after firing, such as an insoluble compound such as an oxide or a carbonate, or a soluble mixture such as an acetate or a chloride. No, the amount of the oxide in the sintered body was 0.1 to 0.6 mol% based on ZrO ₂ containing the stabilizer.
Add so that

As the stabilizing agent, when the obtained pink zirconia sintered body requires high strength, Y which becomes Y ₂ O ₃ after firing is used.
Compounds are most preferable (addition amount is 1.0 mol% to 7.0 mol%).
Mol%), followed but CeO ₂ (10 mol% to 16 mol%) is preferably a high-strength Ca compound when requiring less (fired CaO what will become: 8-12 mol%) and Mg compound ( After firing M
gO: 16-26 mol%) can also be used as a stabilizer.

In the present invention, the content of the colorant, Zr containing a stabilizer
Reason for limiting relative O ₂ in 0.5 to 2.0 mol%, colorant
If it is less than 0.5 mol%, it is difficult to obtain a coloring effect, and if it exceeds 2.0 mol%, the properties of the sintered body are adversely affected.

In the present invention, the addition amount of the sintering aid, including a stabilizer
The reason for limiting the amount to 0.1 to 0.6 mol% with respect to ZrO _{2 is} that if the sintering aid is less than 0.1 mol%, the effect of the auxiliary is difficult to be obtained.
If the amount exceeds mol%, the properties of the sintered body are adversely affected.

Although the calcining temperature in the present invention is 800 to 1100 ° C., the specific surface area of the calcined powder obtained is larger for low-temperature calcining, and lower for high-temperature calcining. May be selected according to the specific surface area of Therefore, the specific surface area
15~20m longitudinal 900 ° C. If it is desired to obtain ² powder, if it is desired to obtain a powder of 6～10M ² preferably calcination temperature of about from 1,000 to 1,050 ° C. is.

The sintering temperature of the pink zirconia in the present invention depends on the specific surface area of the powder and the molding pressure.
In the 6 m ² powder when molding pressure is hydrostatic pressure 2t / cm ² 1300~140
At 0 ° C., a sintered body having a specific surface area of 15 m ^{2 at} a sintering temperature of 1200 to 1300 ° C. and having a theoretical density of 98% or more can be obtained. This sintering temperature is usually zirconia powder commercially available (specific surface area 10 ~
15 m ²⁾ as compared to the sintering temperature (from 1,450 to 1,500 ° C.) of 200 to 300 [° C.
Low temperature. The bending strength of the obtained pink zirconia sintered body is equivalent to that of a commercially available zirconia sintered body (3 mol% containing Y ₂ O ₃ ) when compared by the JIS standard three-point bending method. The above strength is shown.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1 In manufacturing a high-strength pink zirconia sintered body,
Zirconium oxychloride ZrOCl ₂ 200g (1.123 mol), YCl
_{3 6.924g} (0.0355 mol) and ErCl ₃ 6.457g (0.0236 mol)
The coprecipitate formed by dropping an acidic aqueous solution in which was dissolved in aqueous ammonia was filtered, washed with water, and washed with alcohol, and then dried at 110 ° C. under reduced pressure. The obtained dried powder was calcined at 1000 ° C. for 3 hours to obtain a powder having a specific surface area of about 6 m ² . 100 g of this calcined powder
(0.812 mol), 0.536 g (0.00244 mol) of zinc acetate dihydrate and 250 ml of ethanol were added.
After ball milling for 4 hours, the slurry was evaporated to dryness to obtain a raw material powder.

A compact obtained by press-molding this powder under a hydrostatic pressure of 2 t / cm ² was fired at 1300 ° C. for 3 hours to obtain a pink zirconia sintered body. The density, bending strength (JIS standard three-point bending test), and K _IC value (Vickers indentation method) of the obtained sintered body were high as shown in Table 1.

Example 2 200 g (1.123 mol) of oxychlorinated zirconia ZrOCl ₂ , YCl
₃ 9 · 231g (0.473 mol), ErCl ₃ 3.231g (0.0118 mol) was stirred dropwise an aqueous solution prepared by dissolving fold molar amount or more of oxalic acid of these compounds in an acidic aqueous solution obtained by dissolving, filtered and the resulting oxalate precipitate, After washing with water and ethanol, dry under reduced pressure, then 90
The powder was calcined at 0 ° C. for 3 hours to obtain a powder having a specific surface area of 15 m ² . To 100 g (0.812 mol) of this calcined powder, 0.306 g (0.00244 mol) of zinc carbonate was added.
Mol) and 250 ml of ethanol, and ball milled for about 24 hours using zirconia balls. The slurry was evaporated to dryness to obtain a raw material powder.

This powder was pressed under hydrostatic pressure in the same manner as in Example 1 to obtain a powder.
It was fired at 00 ° C. for 3 hours to obtain a pink zirconia sintered body. Table 1 shows the density and mechanical properties of the obtained sintered body.

Example 3 100 g (0.812 mol) of zirconia powder having a specific surface area of 15 m ² containing 2 mol% of Y ₂ O ₃ was well dispersed in 250 ml of an acidic aqueous solution containing 2.435 g (0.00890 mol) of Er ₂ O ₃ using a ball mill or the like. A mixed precipitate of Er oxalate and zirconia powder obtained by dropping 250 ml of an aqueous solution containing oxalic acid at least twice the molar amount of the Er compound is filtered, washed with water, washed with ethanol, dried under reduced pressure, and then heated to 1000 ° C.
For 3 hours to obtain a powder having a specific surface area of 6 m ² . 0.536 g (0.00244 mol) of zinc acetate dihydrate is added to 100 g of this calcined powder.
Then, 250 ml of ethanol and ethanol were added, and the mixture was ball-milled with zirconia balls for 24 hours, and the slurry was evaporated to dryness to obtain a raw material powder. The obtained powder was molded in the same manner as in Example 1 and fired at 1300 ° C. for 3 hours to obtain a pink zirconia sintered body. Table 1 shows the properties of the obtained sintered body.

Comparative Example 1 To 100 g (0.8116 mol) of a commercially available zirconia powder (specific surface area: 15 m ² ) containing 3 mol% of Y ₂ O ₃ , 3.136 g (0.00820 mol) of embium oxide Er ₂ O ₃ as a coloring material was added, and the zirconia ball was used. After ball milling for an hour, the slurry was evaporated to dryness to obtain a raw material powder. The obtained powder was molded in the same manner as in Example 1 and fired at 1200 ° C.

 The results of the obtained sintered body are shown in Table 1.

Comparative Example 2 Zirconium oxychloride ZrOCl ₂ 200 g (1.123 mol), Y
An acidic aqueous solution in which 6.924 g (0.0355 mol) of Cl ₃ and 6.457 g (0.0236 mol) of ErCl ₃ were added dropwise to aqueous ammonia was mixed, and the coprecipitate formed was filtered, washed with water, and washed with alcohol.
It dried under reduced pressure at 0 degreeC. The obtained dried powder was calcined at 1000 ° C. for 3 hours to obtain a powder having a specific surface area of 6 m ² . The calcined powder was ball milled for about 24 hours using ethanol and zirconia balls, and the obtained slurry was evaporated to dryness to obtain a raw material powder. The obtained powder was molded in the same manner as in Example 1, and 1300
Calcination was performed at 3 ° C. for 3 hours.

 Table 1 shows the properties of the obtained sintered body.

In the above example, the case where Y ₂ O ₃ was used as the stabilizer was shown. However, when other stabilizers (CeO ₂ , CaO, MgO) were used, the same low-temperature sintering characteristics were exhibited. A sintered body having a high density and a high strength at a lower temperature than that of the comparative example can be obtained.

〔The invention's effect〕

A pink zirconia sintered body having a low sintering temperature, a clear color tone, and high mechanical strength can be obtained.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C04B 35/42-35/49 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] To 1. A ZrO ₂ containing stabilizing agent, 0.5 to Er ₂ O ₃
A pink zirconia sintered body containing 2.0 mol% and 0.1 to 0.6 mol% of ZnO. 2. A compound which calcinates a mixture obtained from a solution containing a stabilizer, a zirconium compound which becomes ZrO ₂ after firing, and an erbium compound which becomes Er ₂ O ₃ after firing, and then generates zinc oxide by firing. Characterized by uniformly adding, mixing, and shaping and firing. 3. A pink zirconia characterized by comprising adding an erbium compound to a zirconia powder containing a stabilizer, calcining the mixture, further adding a zinc compound which generates zinc oxide by firing, mixing, molding and firing. A method for manufacturing a sintered body.