Claims
- 1. A process for the preparation of shaped translucent lithium disilicate glass ceramic products, which comprises(a) producing a melt of a starting glass containing the following components ComponentWt. %SiO257.0 to 80.0Al2O3 0 to 5.0La2O30.1 to 6.0MgO 0 to 5.0ZnO 0 to 8.0Li2O11.0 to 19.0where (i) Al2O3 + La2O3 accounts for 0.1 to 7.0 wt. % and (ii) MgO + ZnO accounts for 0.1 o 9.0 wt. %, (b) shaping the melt of the starting glass and cooling it, and (c) subjecting the shaped glass product to at least one heat treatment in the temperature range from 400 to 1100° C. in order to obtain a shaped glass ceramic product in the form of a blank.
- 2. A process according to claim 1, wherein(d1) the glass ceramic product in the form of a blank is subjected to plastic shaping at a temperature of 700 to 1200° C. and by the application of pressure to obtain a glass ceramic product of the desired geometry.
- 3. A process for the preparation of shaped translucent lithium disilicate glass ceramic products, which comprises(a) producing a melt of a starting glass containing the following components ComponentWt. %SiO257.0 to 80.0Al2O3 0 to 5.0La2O30.1 to 6.0ZnO 0 to 8.0Li2O11.0 to 19.0where (i) Al2O3 + La2O3 accounts for 0.1 to 7.0 wt. % and (ii) MgO + ZnO accounts for 0.1 to 9.0 wt. %, (b) shaping the melt of the starting glass and cooling it, (c) subjecting the shaped glass product to at least one heat treatment in the temperature range from 400 to 1100° C. in order to obtain a shaped glass ceramic product in the form of a blank, and (d2) processing the glass ceramic product in the form of a blank by machining to a glass ceramic product of the desired geometry.
- 4. A process according to claim 3, wherein a blank is used in (d2) which has undergone a heat treatment at 400 to 900° C. during step (c).
- 5. A process according to claim 3, wherein the shaped glass ceramic product of the desired geometry obtained in stage (d2) is subjected to at least one further heat treatment.
- 6. A process according to claim 1, wherein the heat treatment in stage (c) is carried out at a temperature of less than 1000° C.
- 7. A process according to claim 1, wherein the shaped glass ceramic product of the desired geometry is provided with a coating.
- 8. A process according to claim 7, wherein the coating is a ceramic, a sintered ceramic, a glass ceramic, a glass, a glaze and/or a composite.
- 9. A process according to claim 1, wherein the melt of the starting glass contains at least one of the following further components:ComponentWt. %ZrO20 to 10.0K2O0 to 13.5P2O50 to 11.0Colour and0 to 8.0 fluorescent componentsAdditional components0 to 6.0.
- 10. A process according to claim 9, wherein the quantities of components are selected independently of one another as follows:ComponentWt. %SiO257.0 to 75.0Al2O3 0 to 2.5La2O30.1 to 4.0MgO0.1 to 5.0ZnO 0 to 6.0ZrO2 0 to 8.0K2O 0 to 9.0Li2O13.0 to 19.0P2O5 0 to 8.0colour and0.1 to 8.0fluorescent componentsadditional components 0 to 3.0.
- 11. A process according to claim 9, wherein the colour or fluorescent component used is at least one of the following compounds:ComponentWt. %CeO2 0.1 to 5.0V2O5 0.01 to 1.0Fe2O3 0.01 to 1.0MnO2 0.01 to 3.0TiO2 0.01 to 5.0Y2O3 0.01 to 2.0Er2O30.001 to 2.0Tb2O30.001 to 2.0Eu2O30.001 to 2.0Yb2O30.001 to 2.0Gd2O30.001 to 2.0Nd2O30.001 to 2.0Pr2O30.001 to 2.0Dy2O30.001 to 2.0Ag2O 0.01 to 2.0SnO2 0.01 to 3.0Ta2O5 0.001 to 2.0.
- 12. A process according to claim 10, wherein the additional components are B2O3, Na2O, BaO, F and/or SrO.
- 13. A shaped glass ceramic product produced by the process according to claim 1.
- 14. A glass ceramic product according to claim 13, which has an acid resistance of less than 100 μg/cm2.
- 15. A glass ceramic product according to claim 13, which has a CR value of 0.05 to 0.9, measured at a sample thickness of 1.2 mm.
- 16. A shaped dental restoration, which contains the glass ceramic product according to claim 13.
- 17. A shaped dental restoration, according to claim 16, which is an inlay, an onlay, a bridge, an abutment, a facing, a veneer, a facet, a crown or a partial crown.
- 18. A process according to claim 3, wherein the heat treatment in stage (c) is carried out at a temperature of less than 1000° C.
- 19. A process according to claim 3, wherein the shaped glass ceramic product of the desired geometry is provided with a coating.
- 20. A process according to claim 19, wherein the coating is a ceramic, a sintered ceramic, a glass ceramic, a glass, a glaze and/or a composite.
Priority Claims (1)
Number |
Date |
Country |
Kind |
197 50 794 |
Nov 1997 |
DE |
|
Parent Case Info
This application claims priority benefit of U.S. patent application Ser. No. 60/072,164, filed on Jan. 22, 1998, which is hereby incorporated by reference.
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
4189325 |
Barrett et al. |
Feb 1980 |
A |
4515634 |
Wu et al. |
May 1985 |
A |
5507981 |
Petticrew |
Apr 1996 |
A |
5698482 |
Frank et al. |
Dec 1997 |
A |
5968856 |
Schweiger et al. |
Oct 1999 |
A |
Foreign Referenced Citations (11)
Number |
Date |
Country |
421886 |
Dec 1925 |
DE |
0 231 773 |
Aug 1987 |
EP |
0 536 479 |
Sep 1995 |
EP |
0 536 572 |
Jan 1996 |
EP |
0 690 031 |
Jan 1996 |
EP |
0 827 941 |
Mar 1998 |
EP |
0 885 606 |
Dec 1998 |
EP |
655 264 |
Jun 1991 |
FR |
09-241345 |
Sep 1997 |
JP |
10-165739 |
Nov 1998 |
JP |
10-165741 |
Nov 1998 |
JP |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/072164 |
Jan 1998 |
US |