Glasses Technology

United States Patent Application 20010046934
Kind Code A1
Naumann, Karin ; et al. November 29, 2001
Glasses Patent Abstract
The lead-free bismuth-containing silicate glasses, which are particularly suitable for use as funnel glass or neck glass for cathode ray tubes and as soldering glass, have the following respective compositions (in % by weight, based on oxide): SiO.sub.2 40-60; Bi.sub.2O.sub.3, 10-30; ZrO.sub.2, 0-3; Al.sub.2O.sub.3, 0.5-5; MgO, 0-6; CaO, 0.5-5; SrO, 1-15; BaO, 0-15; sum of the alkaline earth metal oxides, 2-20; ZnO, 0-2; Li.sub.2O, 0-10; Na.sub.2O, 1-10; K.sub.2O, 2-10; Cs.sub.2O, 0-3, sum of the alkali metal oxides, 5-20; CeO.sub.2, 0-8; WO.sub.3, 0.5-5; MoO.sub.3, 0-5 and Sb.sub.2O.sub.3, 0-0.6; and SiO.sub.2 30-50; Bi.sub.2O.sub.3, 20-40; ZrO.sub.2, 0-3; Al.sub.2O.sub.3, 0.5-5; MgO, 0-4; CaO, 0.5-4; SrO, 1-15; BaO, 0-15; sum of the alkaline earth metal oxides, 2-20; ZnO, 0-2; Li.sub.2O, 0-5; Na.sub.2O, 1-12; K.sub.2O, 2-15; Cs.sub.2O, 0-3, sum of the alkali metal oxides, 5-20; CeO.sub.2, 0-8; WO.sub.3, 0.5-5; MoO.sub.3, 0-5 and Sb.sub.2O.sub.3, 0-0.6.

Glasses Patent Claims
We claim:

1. A lead-free bismuth-containing silicate glass have the following composition, in percent by weight based on oxide:

5 SiO.sub.2 40 to 60 Bi.sub.2O.sub.3 10 to 30 ZrO.sub.2 0 to 3 Al.sub.2O.sub.3 0.5 to 5 MgO 0 to 6 CaO 0.5 to 6 SrO 1 to 15 BaO 0 to 15 total alkaline earth metal oxide content 2 to 20 ZnO 0 to 2 Li.sub.2O 0 to 10 Na.sub.2O 1 to 10 K.sub.2O 2 to 10 Cs.sub.2O 0 to 3 total alkali metal oxide content 5 to 20 CeO.sub.2 0 to 8 WO.sub.3 0.5 to 5 MoO.sub.3 0 to 5 Sb.sub.2O.sub.3 0 to 0.6

2. The silicate glass as defined in claim 1, containing at least 0.2% by weight of said MoO.sub.3.

3. The silicate glass as defined in claim 1, containing at least 0.5% by weight of said CeO.sub.2.

4. The silicate glass as defined in claim 1, containing at least 0.2% by weight of said MoO.sub.3 and at least 0.5% by weight of said CeO.sub.2.

5. The silicate glass as defined in claim 1, containing from 15 to 30% by weight of said Bi.sub.2O.sub.3, 0% by weight said ZrO.sub.2, from 0.5 to 6% by weight of said MgO, from 1 to 15% by weight of said BaO, 0% by weight ZnO, from 0 to 5% by weight Li.sub.2O, from 0.5 to 8% by weight CeO.sub.2 and from 0.2 to 5 % by weight MoO.sub.3 and wherein said total content of said alkaline earth metal oxides is from 2 to 15% by weight.

6. The silicate glass as defined in claim 1, having an X-ray absorption coefficient .mu. of more than 60 cm.sup.-1 at 0.06 nm.

7. A funnel glass for a cathode ray tube comprising a lead-free bismuth-containing silicate glass having the following composition, in percent by weight, based on oxide:

6 SiO.sub.2 40 to 60 Bi.sub.2O.sub.3 10 to 30 ZrO.sub.2 0 to 3 Al.sub.2O.sub.3 0.5 to 5 MgO 0 to 6 CaO 0.5 to 6 SrO 1 to 15 BaO 0 to 15 total alkaline earth metal oxide content 2 to 20 ZnO 0 to 2 Li.sub.2O 0 to 10 Na.sub.2O 1 to 10 K.sub.2O 2 to 10 Cs.sub.2O 0 to 3 total alkali metal oxide content 5 to 20 CeO.sub.2 0 to 8 WO.sub.3 0.5 to 5 MoO.sub.3 0 to 5 Sb.sub.2O.sub.3 0 to 0.6

and having an X-ray absorption coefficient .mu. of more than 60 cm.sup.-1 at 0.06 nm.

8. A soldering glass comprising a lead-free bismuth-containing silicate glass having the following composition, in percent by weight, based on oxide:

7 SiO.sub.2 40 to 60 Bi.sub.2O.sub.3 10 to 30 ZrO.sub.2 0 to 3 Al.sub.2O.sub.3 0.5 to 5 MgO 0 to 6 CaO 0.5 to 6 SrO 1 to 15 BaO 0 to 15 total alkaline earth metal oxide content 2 to 20 ZnO 0 to 2 Li.sub.2O 0 to 10 Na.sub.2O 1 to 10 K.sub.2O 2 to 10 Cs.sub.2O 0 to 3 total alkali metal oxide content 5 to 20 CeO.sub.2 0 to 8 WO.sub.3 0.5 to 5 MoO.sub.3 0 to 5 Sb.sub.2O.sub.3 0 to 0.6

9. A lead-free bismuth-containing silicate glass have the following composition, in percent by weight based on oxide:

8 SiO.sub.2 30 to 50 Bi.sub.2O.sub.3 20 to 40 ZrO.sub.2 0 to 3 Al.sub.2O.sub.3 0.5 to 5 MgO 0 to 4 CaO 0.5 to 4 SrO 1 to 15 BaO 0 to 15 total alkaline earth metal oxide content 2 to 20 ZnO 0 to 2 Li.sub.2O 0 to 5 Na.sub.2O 1 to 12 K.sub.2O 2 to 15 Cs.sub.2O 0 to 3 total alkali metal oxide content 5 to 20 CeO.sub.2 0 to 8 WO.sub.3 0.5 to 5 MoO.sub.3 0 to 5 Sb.sub.2O.sub.3 0 to 0.6

10. The silicate glass as defined in claim 9, containing at least 0.2% by weight of said MoO.sub.3.

11. The silicate glass as defined in claim 9, containing at least 0.5% by weight of said CeO.sub.2.

12. The silicate glass as defined in claim 9, containing at least 0.2% by weight of said MoO.sub.3 and at least 0.5% by weight of said CeO.sub.2.

13. The silicate glass as defined in claim 9, containing 0% by weight said ZrO.sub.2, from 0.5 to 4% by weight of said MgO, from 1 to 10% by weight of said SrO, from 1 to 12% by weight of said BaO, 0% by weight ZnO, from 0 to 10% by weight Na.sub.2O, from 0.5 to 8% by weight CeO.sub.2 and from 0.2 to 5% by weight MoO.sub.3 and having a total content of alkaline earth metal oxides of 2 to 15% by weight.

14. The silicate glass as defined in claim 9, having an X-ray absorption coefficient .mu. of more than 60 cm.sup.-1 at 0.06 nm.

15. A funnel glass for a cathode ray tube comprising a lead-free bismuth-containing silicate glass having the following composition, in percent by weight, based on oxide:

9 SiO.sub.2 30 to 50 Bi.sub.2O.sub.3 20 to 40 ZrO.sub.2 0 to 3 Al.sub.2O.sub.3 0.5 to 5 MgO 0 to 4 CaO 0.5 to 4 SrO 1 to 15 BaO 0 to 15 total alkaline earth metal oxide content 2 to 20 ZnO 0 to 2 Li.sub.2O 0 to 5 Na.sub.2O 1 to 12 K.sub.2O 2 to 15 Cs.sub.2O 0 to 3 total alkali metal oxide content 5 to 20 CeO.sub.2 0 to 8 WO.sub.3 0.5 to 5 MoO.sub.3 0 to 5 Sb.sub.2O.sub.3 0 to 0.6

and having an X-ray absorption coefficient .mu. of more than 60 cm.sup.-1 at 0.06 nm.

16. A soldering glass comprising a lead-free bismuth-containing silicate glass having the following composition, in percent by weight, based on oxide:

10 SiO.sub.2 30 to 50 Bi.sub.2O.sub.3 20 to 40 ZrO.sub.2 0 to 3 Al.sub.2O.sub.3 0.5 to 5 MgO 0 to 4 CaO 0.5 to 4 SrO 1 to 15 BaO 0 to 15 total alkaline earth metal oxide content 2 to 20 ZnO 0 to 2 Li.sub.2O 0 to 5 Na.sub.2O 1 to 12 K.sub.2O 2 to 15 Cs.sub.2O 0 to 3 total alkali metal oxide content 5 to 20 CeO.sub.2 0 to 8 WO.sub.3 0.5 to 5 MoO.sub.3 0 to 5 Sb.sub.2O.sub.3 0 to 0.6