Process for producing electrode-formed glass substrate
View Patent ↗A lead-free glass for covering electrodes including, as represented by mass % based on the following oxides, from 30 to 50% of B 2 O 3 , from 21 to 25% of SiO 2 , from 10 to 35% of ZnO, from 7 to 14% in total of K 2 O and either one or both of Li 2 O and Na 2 O, from 0 to 10% of Al 2 O 3 , and from 0 to 10% of ZrO 2 , wherein when it contains at least one component selected from the group consisting of MgO, CaO, SrO and BaO, the total of their contents is at most 5%, and when the molar fractions of Li 2 O, Na 2 O and K 2 O are represented by l, n and k, respectively, l is at most 0.025, and l+n+k is from 0.07 to 0.17.
1. A glass ceramic composition, comprising
a fired mixture of a powder of a lead-free glass and a powder of titanium oxide, wherein
the lead-free glass comprises, as represented by mass % based on the following oxides and relative to the total mass of the lead-free glass,
from 30 to 50% of B 2 O 3 ,
from 21 to 25% of SiO 2 ,
from 10 to 23% of ZnO,
from 9 to 19% in total of K 2 O and at least one of Li 2 O and Na 2 O,
from 0 to 10% of Al 2 O 3 , and
from 0 to 5% of ZrO 2 and optionally at least one component selected from the group consisting of MgO, CaO, SrO and BaO, the total content thereof is at most 5%, with the molar fractions of Li 2 O, Na 2 O and K 2 O represented by l, n and k, respectively, l is at most 0.025, and l+n+k is from 0.08 to 0.17,
the powder of lead-free glass is present in the fired mixture in an amount of from 90 to 99.9 mass %, relative to the total mass of the fired mixture,
the powder of titanium oxide is present in the fired mixture in an amount of from 0.1 to 10 mass %, relative to the total mass of the fired mixture, and
the lead-free glass has a calculated strength index value of at least 1.7.
2. The glass ceramic composition according to claim 1 , which is the form of particles having an average particle diameter of at least 0.5 μm.
3. The glass ceramic composition according to claim 1 , which is the form of particles having an average particle diameter of from 0.5 to 20 μm.
4. The glass ceramic composition according to claim 1 , having a Ts of from 500 to 630° C.
5. The glass ceramic composition according to claim 1 , which comprises, as represented by mass % based on the following oxides and relative to the total mass of the lead-free glass,
from 35 to 50% of B 2 O 3 ,
from 21.5 to 24% of SiO 2 , and
from 12 to less than 20% of ZnO.
6. The glass ceramic composition according to claim 1 , which comprises, as represented by mass % based on the following oxides and relative to the total mass of the lead-free glass,
from 35 to 45% of B 2 O 3 ,
from 21.5 to 23% of SiO 2 , and
from 12 to less than 15% of ZnO.
7. The glass ceramic composition according to claim 1 , wherein the total content of B 2 O 3 , SiO 2 , and Al 2 O 3 is at least 55%, relative to the total mass of the lead-free glass.
8. The glass ceramic composition according to claim 1 , which comprises from 9 to 19 mass % in total of K 2 O and Li 2 O, relative to the total mass of the lead-free glass.
9. The glass ceramic composition according to claim 1 , wherein the total content of B 2 O 3 and SiO 2 is at least 68 mass %, relative to the total mass of the lead-free glass.
10. The glass ceramic composition according to claim 1 , wherein Na 2 O is present with K 2 O and is present in an amount of from 2 to 5 mass %, relative to the total mass of the lead-free glass.
11. The glass ceramic composition according to claim 1 , wherein the lead free glass comprises at most 10 mass % in total of K 2 O and at least one of Li 2 O and Na 2 O, relative to the total mass of the lead-free glass, and l+n+k is from 0.08 to 0.105.
12. The glass ceramic composition according to claim 1 , wherein Al 2 O 3 is present in the lead-free glass in an amount of from 1.4 to 8 mass %, relative to the total mass of the lead-free glass.
13. The glass ceramic composition according to claim 1 , wherein the lead-free glass further comprises CuO in an amount of at most 1.5 mass %, relative to the total mass of the lead-free glass, or
the lead-free glass further comprises CuO, CeO 2 , and CoO and the total content thereof is at most 3 mass %, relative to the total mass of the lead-free glass.
14. A process, comprising forming electrodes on a glass substrate and covering the electrodes with glass, wherein the electrodes are covered with a lead-free glass according to claim 1 .
15. The process according to claim 14 , wherein the lead-free glass has a B 2 O 3 content of at least 43%, a ZnO content of at most 23%, an Li 2 O content of from 0 to 0.5%, an Na 2 O content of from 2 to 5%, a K 2 O content of from 4 to 10%, a total content of Li 2 O, Na 2 O and K 2 O of at most 12%, and an Al 2 O 3 content of from 0 to 5%, and l+n+k is at most 0.11.
16. The process according to claim 14 , wherein the lead-free glass has a total content of B 2 O 3 and SiO 2 of at least 68%.
17. The process according to claim 14 , wherein the lead-free glass does not contain Li 2 O.
18. A process comprising forming electrodes on a glass substrate, firing the glass ceramic composition as defined in claim 1 to form fired glass, and covering the electrodes with the fired glass.