Zirconia layered body

Patent metadata

Field	Value
Publication number	US-11542201-B2
Application number	US-202016801756-A
Country	US
Kind code	B2
Filing date	Feb 26, 2020
Priority date	Mar 7, 2019
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

There is provided at least any of a layered body which has a change in color tone and in which it is unnecessary to select a colorant and the content of the colorant in consideration of a difference in the sintering behavior between layers, a precursor thereof, or a method for producing these. Provided is a layered body which has a structure, in which two or more layers containing stabilizer-containing zirconia and a colorant are layered, and in which types and contents of the colorants contained in the layers are equal to each other, the layered body including at least: a first layer containing a colorant and zirconia which has a stabilizer content of higher than or equal to 3.3 mol %; and a second layer containing a colorant and zirconia which has a stabilizer content different from that of the zirconia contained in the first layer.

First claim

What is claimed is:

1. A layered body which has a structure, in which two or more layers containing stabilizer-containing zirconia and a colorant are layered, and in which types and contents of the colorants contained in the layers are equal to each other, the layered body comprising at least:
a first layer containing a colorant and zirconia which has a stabilizer content of higher than or equal to 4 mol %;
a second layer containing a colorant and zirconia which has a stabilizer content different from that of the zirconia contained in the first layer;
wherein the content of the stabilizer of the stabilizer-containing zirconia contained in the second layer is 4.5 mol % to 7.0 mol %; and
the stabilizer includes one or more selected from the group consisting of yttria, calcia, magnesia, and ceria; and
a difference between the stabilizer content in the first layer and the stabilizer content in the second layer is greater than or equal to 0.5 mol %.

2. The layered body according to claim 1 ,
wherein the content of the stabilizer of the stabilizer-containing zirconia contained in the second layer is 5.0 mol % to 6.0 mol %.

3. The layered body according to claim 1 ,
wherein the content of the stabilizer of the stabilizer-containing zirconia contained in the first layer is 4.1 mol % to 5.5 mol %.

4. The layered body according to claim 1 ,
wherein the stabilizer is any of yttria or ceria.

5. The layered body according to claim 1 ,
wherein the colorant is at least any of a transition metal element or a lanthanoid-based rare earth element.

6. The layered body according to claim 1 ,
wherein the content of the colorant is 0.01 wt % to 1.0 wt %.

7. The layered body according to claim 1 ,
wherein at least one of the layers contains alumina.

8. The layered body according to claim 1 ,
wherein a warp measured using a thickness gauge according to JIS B 7524:2008 is less than or equal to 1.0 mm.

9. The layered body according to claim 1 ,
wherein a warp measured using a thickness gauge according to JIS B 7524:2008 is less than or equal to 0.2 mm.

10. The layered body according to claim 1 ,
wherein the layered body is a sintered body.

11. The layered body according to claim 1 , further comprising:
a zirconia layer of which a total light transmittance with respect to a CIE standard light source D65 at a sample thickness of 1.0 mm is 30% to 50%.

12. The layered body according to claim 1 ,
wherein the layered body is a calcined body.

13. A method for producing the layered body according to claim 1 , comprising:
sintering a green body at 1,200° C. to 1,600° C.,
wherein the green body has a structure, in which two or more powder composition layers consisting of a powder composition containing a stabilizer-containing zirconia, a colorant, and a binding agent are layered, and in which types and contents of the colorants contained in the powder composition layers are equal to each other,
includes at least a first powder composition layer containing a binding agent, a color pigment, and zirconia which has a stabilizer content of higher than or equal to 4 mol % and
a second powder composition layer containing a binding agent, a colorant, and zirconia which has a stabilizer content different from that of the zirconia contained in the first powder composition layer, and
has a difference in a binding agent content between the first powder composition layer and the second powder composition layer exceeds 0.01 wt %.

14. A method for producing the layered body according to claim 1 , comprising:
calcining a green body at a temperature of higher than or equal to 800° C. and lower than 1,200° C. to obtain a calcined body; and
sintering the calcined body at 1,200° C. to 1,600° C.,
wherein the green body has a structure, in which two or more powder composition layers consisting of a powder composition containing a stabilizer-containing zirconia, a colorant,
and a binding agent are layered, and in which types and contents of the colorants contained in the powder composition layers are equal to each other,
includes at least a first powder composition layer containing a binding agent, a colorant, and zirconia which has a stabilizer content of higher than or equal to 4 mol % and
a second powder composition layer containing a binding agent, a colorant, and zirconia which has a stabilizer content different from that of the zirconia contained in the first powder composition layer, and
has a difference in a binding agent content between the first powder composition layer and the second powder composition layer exceeds 0.01 wt %.

15. A method for producing the layered body according to claim 1 , comprising:
calcining a green body at a temperature of higher than or equal to 800° C. and lower than 1,200° C.,
wherein the green body has a structure, in which two or more powder composition layers consisting of a powder composition containing a stabilizer-containing zirconia, a colorant, and a binding agent are layered, and in which types and contents of the colorants contained in the powder composition layers are equal to each other,
includes at least a first powder composition layer containing a binding agent, a colorant, and zirconia which has a stabilizer content of higher than or equal to 4 mol % and
a second powder composition layer containing a binding agent, a colorant, and zirconia which has a stabilizer content different from that of the zirconia contained in the first powder composition layer, and
has a difference in a binding agent content between the first powder composition layer and the second powder composition layer exceeds 0.01 wt %.

16. The production method according to claim 13 ,
wherein the binding agent is one or more selected from the group consisting of polyvinyl alcohol, polyvinyl butyrate, wax, and acrylic resin.

17. The production method according to claim 13 ,
wherein the powder composition contained in the powder composition layers is granulated powder.

18. A dental material containing the layered body according to claim 1 .

Assignees

• Tosoh Corp

Inventors

• Ushio Yuki
• Ito Yuuki
• Azechi Sho
• Fujisaki Hiroyuki

Classifications

• C04B2235/3217

  Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina · CPC title

• C04B2237/582

  by joining layers or articles of the same composition but having different additives · CPC title

• C04B35/48 Primary

  based on zirconium or hafnium oxides, zirconates, {zircon} or hafnates · CPC title

• C04B2235/3277

  Co3O4 · CPC title

• C04B16/065

  Polyacrylates; Polymethacrylates · CPC title