JPH075325B2 - Color pigment of zirconia-based fine ceramics and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coloring pigment of zirconia-based fine ceramics and a method for producing the same.

[Conventional technology]

Conventionally, in the case of coloring zirconia-based fine ceramics, a method has been used in which a coloring agent composed of a transition metal oxide, such as cobalt oxide or manganese oxide, is directly mixed into a ceramic base material, and the mixture is molded and then sintered. Was there.

[Problems to be Solved by the Invention]

By the way, the above ceramic base materials generally contain stabilizers such as yttrium oxide and cerium oxide in order to obtain the stability of the sintered pair, but these stabilizers have a larger ionic diameter than zirconium. Therefore, as described above, in the coloring method in which a coloring agent having a smaller ion diameter than that of zirconium is directly mixed in the ceramic, there is a problem that the effect of the stabilizer is hindered and the stability of the ceramic sintered body is hindered. It was

The reason for this inhibition is that the stabilizer mainly contained in the base material reacts with the colorant during ceramics sintering, and the stabilizer segregates in the sintered body, resulting in a local lack of the stabilizer. The local lack of the stabilizer resulted in a decrease in the stability of the sintered body.

Then, the technical subject of this invention is providing the coloring pigment which can improve the stability of the zirconia type | system | group fine ceramics which used a transition metal oxide as a coloring agent, and its manufacturing method.

[Means for Solving the Problems]

MEANS TO SOLVE THE PROBLEM This invention solves the said technical subject. The zirconia type | system | group fine ceramics synthesize | combined with the coloring agent containing a transition metal oxide, and a coloring aid of at least 1 sort (s) of a rare earth metal oxide, magnesia, and a calcia. As a first means, the coloring material of a coloring agent containing a transition metal oxide is mixed with a powdering material of a coloring aid of at least one of rare earth metal oxide, magnesia and calcia, and the mixture is mixed. After firing
A second method is a method for producing a coloring pigment of zirconia-based fine ceramics, which is characterized by being pulverized and synthesized.

As the colorant, for example, cobalt oxide, manganese oxide,
Transition metal oxides such as vanadium oxide, chromium oxide, nickel oxide, iron oxide and copper oxide may be used alone or as a mixture of several kinds, or those containing a part thereof may also be the colorant.

As the coloring aid, one that does not impair the stability of the ceramic base material and the stabilizer added to the base material is used, and examples thereof include rare earth metal oxides such as yttrium oxide and cerium oxide, aluminum oxide, and silicon oxide. , Magnesium oxide and calcium oxide are used.

The ceramic base material generally contains a stabilizer such as yttrium oxide or cerium oxide.

Next, a method for producing the pigment according to the present invention will be described.

First, one kind or two or more kinds of colorants prepared in powder form,
One or more coloring aids prepared in the same manner are thoroughly mixed. Next, this mixed raw material is sintered mainly in an oxidizing atmosphere at 800 ° C. or higher and then pulverized to obtain a pigment having a particle size (submicron) similar to that of the base material. The coloring agent and the coloring aid used as the starting materials do not have to be in an oxide state from the beginning, and may be synthesized into an oxide pigment in the firing process in an oxidizing atmosphere.

On the other hand, in the case of coloring zirconia-based fine ceramics using the pigment thus obtained, a predetermined amount of the pigment is mixed with the ceramic base material, sufficiently mixed and stirred, and then molded and sintered. A colored ceramic is obtained. Sintering is, for example, 1450 ° C in the atmosphere
For 4 hours.

[Action]

In the thus-obtained colored ceramics, the coloring pigment is a material similar to the material used as the stabilizer, for example, rare earth metal oxides such as yttrium oxide and cerium oxide, magnesium oxide, and calcium oxide. Since the coloring pigment is preliminarily synthesized from a coloring aid consisting of at least one kind and a colorant containing a transition metal oxide, and this coloring pigment is added to the ceramic base material, the coloring aid and the coloring agent are mixed during the synthesis of the coloring pigment. Are already bonded, and the reaction between the stabilizer contained in the ceramic base material and the colorant contained in the color pigment is suppressed during the ceramics sintering. Therefore, segregation of the stabilizer in the ceramic sintered body is prevented, and the amount of the stabilizer is not locally insufficient, and the stability of the sintered body is improved. .

Hereinafter, specific examples of the present invention will be described.

〔Example〕

Zirconia-based fine ceramics containing yttrium oxide as a stabilizer (3mol% Y ₂ O ₃ -Zr ₂ O ₃ ) was used as a base material, and a black colorant was added to and mixed with it, followed by molding and firing. The stability of the ceramic sintered body when bonded was evaluated.

The composition and blending ratio of the coloring agent used are shown in Table 1, and the addition amount of each of the base material, the coloring agent, and the coloring auxiliary agent and the presence or absence of the pigment manufacturing process using the coloring agent and the coloring auxiliary agent or the coloring agent alone are shown in Table 2. It was shown to. In Table 2, sample Nos. 1 to 4 are examples of the present invention, and sample Nos. 5 to 7 are comparative examples.

If there is a pigment manufacturing step, it means that the coloring agent and the coloring auxiliary agent are mixed and then heat-treated at 850 ° C. for 3 hours in an oxidizing atmosphere. It means that there is a step of heat-treating and then crushing this to a pigment, and that there is no pigment manufacturing step means adding directly to the base material without passing through these heat-treatment crushing steps.

The bending strength, the segregation of the stabilizer, the monoclinic ratio and the surface state of each of the samples thus obtained were measured, and the results are summarized in Table 3. The bending strength was measured by measuring the three-point bending strength of the sintered body, the segregation of the stabilizer was relatively evaluated by qualitative analysis with an electron beam, and the monoclinic fraction was heat treated at 150 ° C for 50 hours in the atmosphere. The ratio of monoclinic crystals near the surface of the sintered body was measured by X-ray analysis, and the surface state was a relative evaluation of the surface state of the heat-treated sintered body by an electron microscope.

[Effect] As described above, according to the coloring pigment of the zirconia-based fine ceramics according to the present invention, since the coloring aid and the coloring agent are preliminarily synthesized, they are contained in the ceramic base material during the sintering of the ceramics. Since the reaction between the stabilizer being used and the colorant contained in the color pigment is suppressed, it is possible to improve the stability of the zirconia-based fine ceramics colored using this color pigment. As a result, stability comparable to that of a non-colored ceramic sintered body can be obtained.

Further, the method for producing a pigment according to the present invention is a simple means of mixing a colorant and a coloring aid, sintering and crushing, and an effect that it does not become a burden on the working process. There is.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C01G 45/00 49/00 A 53/00 A C04B 35/48

Claims (2)

[Claims] 1. A colorant containing a transition metal oxide and at least one of rare earth metal oxides, magnesia and calcia.
A coloring pigment of zirconia-based fine ceramics, characterized in that it is synthesized with a coloring aid of one kind. 2. A raw material powder of a colorant containing a transition metal oxide and a raw material powder consisting of at least one coloring aid of rare earth metal oxides, magnesia and calcia are mixed and baked, A method for producing a color pigment of zirconia-based fine ceramics, characterized by being pulverized and synthesized.