Patent US3239549A successfully refreshed from Google Patents.
US3239549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alkali metal and quaternary ammonium double salts of silicic acid
Assignee: PQ Corp
•
Filing: 1960-08-22
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Granted: 1966-03-08
•
Expires: 1980-08-22
Abstract
No abstract record available.
Inventors
- 👤 Weldes Helmut Hans Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:22
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C01; C01B; C01B37/00; C01B37/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
5 words
A COMPOUND HAVING THE FORMULA:
Claim 2
Dependent Claim
5 words
A COMPOUND HAVING THE FORMULA:
Claim 3
Dependent Claim
8 words
A PSEUDO-CUBIC, ANISOTROPIC CRYSTALLINE COMPOUND HAVING THE FORMULA
Claim 4
Dependent Claim
8 words
A PSEUDO-CUBIC, ANISOTROPIC CRYSTALLINE COMPOUND HAVING THE FORMULA
References Cited (Backward Citations)
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US2137314A
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US2618606A
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US2689245A
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US2839558A
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US2873282A
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US2765307A
Cited
CH335526A
Cited
US2784106A
Cited
US2844482A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-03-07 | 1969-09-06 | 1970-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-07 | 1973-09-06 | 1974-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-07 | 1977-09-06 | 1978-03-08 | $7700.00 | Window Closed / Lapsed |