US2759798A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low density silica gel
Assignee: WR Grace and Co
•
Filing: 1953-06-30
•
Granted: 1956-08-21
•
Expires: 1973-06-30
Abstract
No abstract record available.
Inventors
- 👤 Charles E Waring
- 👤 Dorothy K Shipley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:49
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
44 words
THE PROCESS OF FORMING A RELATIVELY LOW DENSITY SILICA GEL WHICH COMPRISES ACIDIFYING WITH A MINERAL ACID A SOLUTION OF AN ALKALI METAL SILICATE CONTAINING AN AQUEOUS EMULSION OF A SATURATED LOWER ALIPHATIC CARBOXYLIC ACID ESTER TO FORM A GALATINOUS PRECIPITATE OF SILICA HYDROGEL.
Claim 2
Dependent Claim
44 words
THE PROCESS OF FORMING A RELATIVELY LOW DENSITY SILICA GEL WHICH COMPRISES ACIDIFYING WITH A MINERAL ACID A SOLUTION OF AN ALKALI METAL SILICATE CONTAINING AN AQUEOUS EMULSION OF A SATURATED LOWER ALIPHATIC CARBOXYLIC ACID ESTER TO FORM A GALATINOUS PRECIPITATE OF SILICA HYDROGEL.
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) | 1959-08-21 | 1960-02-20 | 1960-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-08-21 | 1964-02-20 | 1964-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-08-21 | 1968-02-20 | 1968-08-21 | $7700.00 | Window Closed / Lapsed |