Glass Ceramic Having SiO2 As Main Crystal Phase

Patent metadata

Field	Value
Publication number	US-2021340057-A1
Application number	US-202117372663-A
Country	US
Kind code	A1
Filing date	Jul 12, 2021
Priority date	May 16, 2014
Publication date	Nov 4, 2021
Grant date	—

Abstract

Glass ceramics having SiO 2 as main crystal phase and precursors thereof are described which are characterized by very good mechanical and optical properties and in particular can be used as restoration material in dentistry.

First claim

1 . Glass ceramic, which comprises the following components

Component
wt.-%

SiO 2
58.0 to 92.0

Li 2 O
 2.0 to 10.0

and comprises SiO 2 as main crystal phase.

2 . Glass ceramic according to claim 1 , which comprises 60.0 to 90.0 wt.-% SiO 2 .

3 . Glass ceramic according to claim 1 , which comprises 2.8 to 9.0 wt.-% Li 2 O.

4 . Glass ceramic according to claim 1 , which comprises 0 to 13.0 wt.-% further alkali metal oxide Me I 2 O.

5 . Glass ceramic according to claim 1 , which comprises 0 to 11.0 wt.-% oxide of divalent elements Me II O.

6 . Glass ceramic according to claim 1 , which comprises 0 to 10.0 wt.-% oxide of trivalent elements Me III 2 O 3 .

7 . Glass ceramic according to claim 1 , which comprises 0 to 21.0 wt.-% further oxide of tetravalent elements Me IV O 2 .

8 . Glass ceramic according to claim 1 , which comprises 0 to 7.0 wt.-% P 2 O 5 .

9 . Glass ceramic according to claim 1 , which comprises 0 to 6.0 wt.-% further oxide of pentavalent elements Me V 2 O 5 .

10 . Glass ceramic according to claim 1 , which comprises 0 to 6.0 wt.-% oxide of hexavalent elements Me VI O 3 .

11 . Glass ceramic according to claim 1 , which comprises at least one of the following components in the specified amounts:

Component
wt.-%

Me I 2 O
  0 to 13.0

Me II O
  0 to 11.0

Me III 2 O 3
  0 to 10.0

Me IV O 2
  0 to 21.0

P 2 O 5
 0 to 7.0

MeV 2 O 5
 0 to 6.0

Me VI O 3
 0 to 6.0

fluorine
  0 to 5.0.

12 . Glass ceramic according to claim 1 , which comprises low quartz, cristobalite or a mixture thereof as main crystal phase.

13 . Glass ceramic according to claim 1 , which comprises 5.0 to 50.0 wt.-% SiO 2 as crystal phase.

14 . Glass ceramic according to claim 1 , which comprises lithium phosphate and/or lithium silicate as further crystal phase.

15 . Glass ceramic according to claim 1 , wherein the glass ceramic is present in the form of a powder, a frit, a blank or a dental restoration.

16 . Glass ceramic according to claim 1 , wherein the glass ceramic is present in the form of a dental restoration and wherein the dental restoration comprises a bridge, inlay, onlay, veneer, abutment, partial crown, crown or facet.

17 . Starting glass, which comprises the following components

Component
wt.-%

SiO 2
58.0 to 92.0

Li 2 O
 2.0 to 10.0

and comprises nuclei for the crystallization of SiO 2 as main crystal phase.

18 . Process for the preparation of the glass ceramic according to claim 1 , in which a starting glass which comprises the following components

Component
wt.-%

SiO 2
58.0 to 92.0

Li 2 O
 2.0 to 10.0

is subjected to at least one heat treatment at a temperature of from 700 to 950° C.

19 . Process according to claim 18 , wherein
(a) powder of the starting glass, optionally after the addition of further components, is pressed to form a powder compact, and (b) the powder compact is subjected to a heat treatment at a temperature of 700 to 950° C.; or (a′) melt of the starting glass is shaped to form a glass blank, and (b′) the glass blank is subjected to a heat treatment at a temperature of 700 to 900° C.

20 . Process for the preparation of a dental restoration, in which the glass ceramic according to claim 1 is given the shape of the desired dental restoration by pressing, sintering or machining.

Assignees

• Ivoclar Vivadent Ag

Inventors

• Rampf Markus
• Dittmer Marc
• Ritzberger Christian
• Schweiger Marcel
• Höland Wolfram

Classifications

• C03C4/0021

  for dental use · CPC title

• A61K6/833

  Glass-ceramic composites · CPC title

• C03C3/085

  containing an oxide of a divalent metal · CPC title

• C03C10/0009 Primary

  containing silica as main constituent · CPC title

• A61K6/836

  Glass · CPC title