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US 5,618,763 AGranted
Alkali-zinc-silicate glass-ceramics and glasses
AssigneeIvoclar AG
InventorsMartin Frank, Susanne Wegner, Volker Rheinberger, Wolfram Hoeland
Life of this patent
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Abstract
Alkali-zinc-silicate glass ceramics and glasses are described which have a linear thermal expansion coefficient in the range from 8.0 to 18.7.times.10.sup.-6 K.sup.-1, an excellent chemical resistance and other advantageous optical properties and can be used in particular as dental material.
Claims14
An alkali-zinc-silicate glass-ceramic, comprising the following components:
- ______________________________________ Components % by wt. ______________________________________ SiO.sub.2 52.0 to 63.5 Me(III).sub.2 O.sub.3 8.5 to 13.0 K.sub.2 O 0 to 20.5 Na.sub.2 O 1.5 to 20.0 Li.sub.2 O 0 to 5.0 ZnO 3.6 to 8.0 Me(II)O 2.5 to 6.5 TiO.sub.2 + ZrO.sub.2 0.5 to 6.0 SnO.sub.2 0 to 9.5 P.sub.2 O.sub.5 0 to 4.0 F 0 to 2.0 CeO.sub.2 0 to 3.0 ______________________________________
- where
- a) Me(III).sub.2 O.sub.3 is formed from 0 to 13% by wt. Al.sub.2 O.sub.3 and 0 to 9.5% by wt. La.sub.2 O.sub.3 ;
- and
- b) Me(II)O is formed from 0 to 3.5% by wt. CaO, 0 to 4.5% by wt. BaO and 0 to 5.0% by wt. MgO.
2 more elements
A process for producing a glass ceramic having the following components:
- ______________________________________ Components % by wt. ______________________________________ SiO.sub.2 52.0 to 63.5 Me(III).sub.2 O.sub.3 8.5 to 13.0 K.sub.2 O 0 to 20.5 Na.sub.2 O 1.5 to 20.0 Li.sub.2 O 0 to 5.0 ZnO 3.6 to 8.0 Me(II)O 2.5 to 6.5 TiO.sub.2 + ZrO.sub.2 0.5 to 6.0 SnO.sub.2 0 to 9.5 P.sub.2 O.sub.5 0 to 4.0 F 0 to 2.0 CeO.sub.2 0 to 3.0 ______________________________________
- where
- a) Me(III).sub.2 O.sub.3 is formed from 0 to 13% by wt. Al.sub.2 O.sub.3 and 0 to 9.5% by wt. La.sub.2 O.sub.3 ;
- and
- b) Me(II)O is formed from 0 to 3.5% by wt. CaO, 0 to 4.5% by wt. BaO and 0 to 5.0% by wt. MgO;
- comprising producing a glass having the above composition;
- and subjecting the glass to a heat treatment at a temperature of from 600.degree. to 900.degree. C. from 30 minutes to 5 hours.
4 more elements
An alkali-zinc-silicate glass, comprising the following components:
- ______________________________________ Components % by wt. ______________________________________ SiO.sub.2 52.0 to 63.5 Me(III).sub.2 O.sub.3 8.5 to 13.0 K.sub.2 O 0 to 20.5 Na.sub.2 O 1.5 to 20.0 Li.sub.2 O 0 to 5.0 ZnO 3.6 to 8.0 Me(II)O 2.5 to 6.5 TiO.sub.2 + ZrO.sub.2 0.5 to 6.0 SnO.sub.2 0 to 9.5 P.sub.2 O.sub.5 0 to 4.0 F 0 to 2.0 CeO.sub.2 0 to 3.0 ______________________________________
- where
- a) Me (III).sub.2 O.sub.3 is formed from 0 to 13% by wt. Al.sub.2 O.sub.3 and 0 to 9.5% by wt. La.sub.2 O.sub.3 ;
- b) Me(II)O is formed from 0 to 3.5% by wt. CaO, 0 to 4.5% by wt. BaO and 0 to 5.0% by wt. MgO;
- and
- c) the glass contains no B.sub.2 O.sub.3.
3 more elements
Dependencies are inferred from the claim text.