US4522925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing glass and method of making a Willemite filler therefor
Assignee: Techneglas LLC
•
Filing: 1983-09-01
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Granted: 1985-06-11
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Expires: 2003-09-01
Abstract
Abstract A sealing glass composition comprising a lead borate glass matrix and a Willemite filler that provides a blended sealing glass composition with outstanding properties including excellent thermal (button flow and rod seal stress values) and chemical properties. A method of making the Willemite filler is described, the method including critical firing times and temperatures in order to produce the highly effective filler.
Inventors
- 👤 Perry P. Pirooz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:50
CPC Classifications
C; C03; C03C; C03C8/00; C03C8/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
119 words
A sealing glass composition consisting essentially of about 65 parts by weight of a lead borate glass matrix and 35 parts by weight of a Willemite (zinc orthosilicate) filler, the Willemite (zinc orthosilicate) being made by mixing about 73 parts by weight of ZnO and about 27 parts by weight of SiO 2 and firing the mixture at about 1350° C. for about 24 hours and milling the product to provide finely divided Willemite (zinc orthosilicate) with a particle size comprising about 85% finer than 38 microns, the lead borate glass having the following ingredients in approximate weight percents: ______________________________________
Ingredients
Wt. %
______________________________________
PbO 83
B.sub.2 O.sub.3
12.5
Bi.sub.2 O.sub.3
3
SiO.sub.2
0.5
ZnO 0.5
BaO 0.5
______________________________________
Claim 2
Dependent Claim
119 words
A sealing glass composition consisting essentially of about 65 parts by weight of a lead borate glass matrix and 35 parts by weight of a Willemite (zinc orthosilicate) filler, the Willemite (zinc orthosilicate) being made by mixing about 73 parts by weight of ZnO and about 27 parts by weight of SiO 2 and firing the mixture at about 1350° C. for about 24 hours and milling the product to provide finely divided Willemite (zinc orthosilicate) with a particle size comprising about 85% finer than 38 microns, the lead borate glass having the following ingredients in approximate weight percents: ______________________________________
Ingredients
Wt. %
______________________________________
PbO 83
B.sub.2 O.sub.3
12.5
Bi.sub.2 O.sub.3
3
SiO.sub.2
0.5
ZnO 0.5
BaO 0.5
______________________________________
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |