US3050408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite lead-oxide-silica particles
Assignee: NL Industries Inc
•
Filing: 1959-04-28
•
Granted: 1962-08-21
•
Expires: 1979-04-28
Abstract
No abstract record available.
Inventors
- 👤 Joseph A Orsino
- 👤 Jr Edward J Dunn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:21
CPC Classifications
C; C01; C01G; C01G21/00; C01G21/02
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
126 words
A PROCESS FOR THE MANUFACTURE OF A SILICA CORED LEAD OXIDE PARTICLE COMPRISING THE STEPS OF PREPARING A SLURRY OF SILICA AND AT LEAST ONE LEAD OXIDE, SAID LEAD OXIDE BEING PRESENT IN AMOUNT FROM 20% TO 95% INCLUDING AT LEAST 5% RED LEAD, AND SAID SILICA BEING PRESENT IN AMOUNT FROM 5% TO 80% ALL PERCENTAGES BEING BASED ON THE COMBINED TOTAL WEIGHT OF SILICA AND LEAD OXIDE, GRINDING SAID SLURRY FOR AT LEAST 4 HOURS DELIQUORING SAID SLURRY, AND CALCINING THE SOLID PORTION THEREOF FOR AT LEAST 2 AND NOT MORE THAN 8 HOURS AT ELEVATED TEMPERTURE, WHEREIN SAID ELEVATED TEMPERATURE IS FROM 450*C. TO 600*C., THE TIME AND TEMPERATURE OF CALCINATION BEING SO RELATED THAT THE SOLID PORTION CONTAINS RED LEAD THROUGHOUT CALCINATION.
References Cited (Backward Citations)
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Cited
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US2236051A
Cited
US2563367A
Cited
US2649388A
Cited
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Cited
US2913419A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-08-20 | 1966-02-19 | 1966-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-08-20 | 1970-02-19 | 1970-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-08-20 | 1974-02-19 | 1974-08-21 | $7700.00 | Window Closed / Lapsed |