Claims
- 1. A vitroceramic body consisting essentially of the following ingredients in the approximate weight percent:
- Al.sub.2 O.sub.3 + SiO.sub.2 57-63% of which Al.sub.2 O.sub.3 is 4-10%,CaO + MgO 20-26% of which CaO is 13-20% and MgO is 3.5-8%,Na.sub.2 O + K.sub.2 O 9-12% and Na.sub.2 O > K.sub.2 O,F 5-9%,BaO <10%,ZnO <5%,Impurities <5%,
- the BaO and ZnO when present replacing equimolar parts of MgO, the said composition being vitreous with a dispersed devitrified phase and being substantially devoid of sulfur.
- 2. A vitroceramic composition according to claim 1 in which the impurities are less than about 21/2% by weight.
- 3. A vitroceramic body according to claim 1 in which the ratio by weight of CaO to MgO is between about 2 and 4.
- 4. A vitroceramic body having a vitreous constitution with a dispersed devitrified phase which consists essentially of about 55.3% weight % SiO.sub.2, 5.9% Al.sub.2 O.sub.3, 19.3% CaO, 4.6% MgO, 9.5% Na.sub.2 O, and 5.2% F and being substantially devoid of sulfur.
- 5. A vitroceramic body having a vitreous constitution with a dispersed devitrified phase consisting essentially of about 55.3% SiO.sub.2, 8% Al.sub.2 O.sub.3, 17.6% CaO, 4.2% MgO, 1% BaO, 8.7% Na.sub.2 O, 6% F and being substantially devoid of sulfur.
- 6. A vitroceramic body having a vitreous constitution with a dispersed devitrified phase consisting essentially of about 54.3% SiO.sub.2, 5.8% Al.sub.2 O.sub.3, 19% CaO, 4.5% MgO, 9.3% Na.sub.2 O, and 7% F and being substantially devoid of sulfur.
- 7. A vitroceramic body having a vitreous constitution with a dispersed devitrified phase consisting essentially of about 57.3% SiO.sub.2, 6% Al.sub.2 O.sub.3, 17.8% CaO, 4.5% MgO, 6.1% Na.sub.2 O, 3.1% K.sub.2 O, and 5.1% F and being substantially devoid of sulfur.
Priority Claims (1)
Number |
Date |
Country |
Kind |
69.15707 |
May 1969 |
FR |
|
Parent Case Info
This application is a continuation-in-part of my corresponding application Ser. No. 246,847 filed Apr. 24, 1972, now abandoned, in turn, was a division of Application No. 37,037 filed May 13, 1970 which latter case is now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
3170780 |
Takehara et al. |
Feb 1965 |
|
Foreign Referenced Citations (2)
Number |
Date |
Country |
1,345,069 |
Oct 1964 |
FR |
848,447 |
Sep 1960 |
UK |
Divisions (1)
|
Number |
Date |
Country |
Parent |
37037 |
May 1970 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
246847 |
Apr 1972 |
|