Patent US3696864A successfully refreshed from Google Patents.
US3667976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Colored cement
Assignee: General Portland Cement Co
•
Filing: 1970-06-30
•
Granted: 1972-06-06
•
Expires: 1990-06-30
Abstract
Abstract CEMENT, AND PARTICULARLY PORTLAND CEMENT, CAN BE COLORED TO A VARIETY OF DIFFERENT HUES BY ADMIXING SELECTED METALS WITH THE RAW MATERIALS FROM WHICH THE CEMENT IS MADE PRIOR TO OR DURING BURNING OF THE RAW MATERIALS. THE METELS CAN BE INTRODUCED IN ELEMENTAL OR COMBINED FORM. GENERALLY, THE METALS ARE INTRODUCED IN AMOUNTS FROM 0.2 TO 2.0% BY WEIGHT EXPRESSED AS THE OXIDE OF THE METAL BASED ON THE TOTAL AMOUNT OF DRY RAW MATERIALS WHICH ARE INTRODUCED INTO THE KILN. BURNING TEMPERATURES AT WHICH THE RAW MATERIALS AND COLORING AGENT ARE REACTED ARE CONVENTIONAL.
Inventors
- 👤 Theodore F Tanner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:07
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/36; C04B7/38; C04B7/42
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |