Lithium silicate glass ceramic

Patent metadata

Field	Value
Publication number	US-11117829-B2
Application number	US-201916527122-A
Country	US
Kind code	B2
Filing date	Jul 31, 2019
Priority date	Oct 7, 2016
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

The invention relates to a lithium silicate glass ceramic, which contains at least lithium disilicate as a crystal phase, and lithium aluminum silicate as further crystal phase. The lithium silicate glass ceramic in its initial composition contains Al 2 O 3 at 1.5 to 3.5 percent by weight, and K 2 O at 0.6 to 1.8 percent by weight.

First claim

The invention claimed is:

1. A lithium silicate glass ceramic intended for a dental molded body, comprising at least lithium disilicate crystals/crystallites and lithium aluminum silicate crystals/crystallites as crystal phases, wherein the dental molded, body is formed from a composition that includes Al 2 O 3 at 1.5 to 3.5 percent by weight, and K 2 O at 0.6 to 1.8 percent by weight.

2. The lithium silicate glass ceramic according to claim 1 , wherein the lithium silicate glass ceramic includes lithium disilicate crystals/crystallites as a main crystal phase.

3. The lithium silicate glass ceramic according to claim 1 , wherein besides lithium aluminum silicate crystals/crystallites, the lithium silicate glass ceramic includes exclusively lithium disilicate crystals/crystallites and lithium phosphate crystals/crystallites as crystal phases.

4. The lithium silicate glass ceramic according to claim 1 , wherein the lithium silicate glass ceramic includes:
spodumene crystals/crystallites at a percentage of more than 0 vol % to 10 vol % of the lithium silicate glass ceramic, and virgilite crystals/crystallites at a percentage of greater than 0 vol % to 5 vol % of the lithium silicate glass ceramic.

5. The lithium silicate glass ceramic according to claim 1 , wherein the lithium silicate glass ceramic includes sogdianite crystals/crystallites at a percentage of greater than 0 vol % to 20 vol % of the lithium silicate glass ceramic.

6. The lithium silicate glass ceramic according to claim 1 , wherein the lithium silicate glass ceramic includes spodumene crystals/crystallites and sogdianite crystals/crystallites as crystal phases.

7. The lithium silicate glass ceramic according to claim 3 , wherein the percentage by volume of the lithium phosphate crystals/crystallites and lithium disilicate crystals/crystallite in the range 40 vol % to 60 vol % of the lithium silicate glass ceramic.

8. The lithium silicate glass ceramic according to claim 1 , wherein the lithium aluminum silicate crystals/crystallites assemble/form on the lithium disilicate crystals/crystallites within the lithium silicate glass ceramic.

9. The lithium silicate glass ceramic according to claim 4 , wherein the length LS of the spodumene crystals/crystallites is 1 nm≤LS≤500 nm.

10. The lithium silicate glass ceramic according to claim 4 , wherein the length LV of the virgilite crystals/crystallites is 0.2 μm≤LV≤20 μm.

11. The lithium silicate glass ceramic according to claim 1 , wherein the starting composition includes the following in percentage by weight

SiO 2
54.0 to 62.0

P 2 O 5
5.0 to 6.0

Al 2 O 3
1.5 to 3.5

Li 2 O
13.0 to 16.0

K 2 O
0.6 to 1.8

ZrO 2
 8.0 to 11.5

B 2 O 3
  0 to 6.0

Na 2 O
  0 to 1.9

color pigments
  0 to 8.0

and/or one or more additives being

selected from the groug consisting of MnO,

Fe 2 O 3 , Tb 2 O 3 , Er 2 O 3 , Pr 2 O 3 , CeO 2 Y 2 O 3 ,

and V 2 O 3 .

12. The lithium silicate glass ceramic according to claim 1 , wherein the starting composition includes the following in percentage by weight

SiO 2
57.0 to 60.0

P 2 O 5
5.2 to 5.6

Al 2 O 3
2.6 to 3.2

Li 2 O
13.5 to 15.0

K 2 O
0.8 to 1.4

ZrO 2
 9.0 to 11.0

B 2 O 3
  0 to 5.0

Na 2 O
  0 to 1.5

color pigments and/or one or more
2.0 to 7.0

additives being selected from the

group consisting of MnO, Fe 2 O 3 ,

Tb 2 O 3 , Er 2 O 3 , Pr 2 O 3 , CeO 2 , Y 2 O 3 ,

and V 2 O 3 .

13. The lithium silicate glass ceramic according to claim 1 , wherein the starting composition includes the following in percentage by weight

SiO 2
58

P 2 O 5
5

Al 2 O 3
3

Li 2 O
15

K 2 O
1

ZrO 2
10

color pigments
4

that include at least one of MnO, Fe 2 O 3 ,

Tb 2 O 3

Assignees

• Dentsply Sirona Inc

Inventors

• Vollmann Markus
• Wissel Irmgard
• Meegdes Marcel
• Wiesner Carsten

Classifications

• C03C3/093

  containing zinc or zirconium · CPC title

• C03B32/02

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• C03C10/0009

  containing silica as main constituent · CPC title

• C03C3/097

  containing phosphorus, niobium or tantalum · CPC title