Patent US3520140A successfully refreshed from Google Patents.
US3520140A
Expired / Lapsed
US
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Soil sealing method
Assignee: Dow Chemical Co
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Filing: 1967-10-12
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Granted: 1970-07-14
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Expires: 1987-10-12
Abstract
No abstract record available.
Inventors
- 👤 Melvin F Katzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:10
CPC Classifications
C; C09; C09K; C09K17/00; C09K17/14; C09K17/18; C09K17/20; C09K17/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US668362A
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US2865177A
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US2801984A
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US2842338A
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US3016713A
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US3021298A
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US3181612A
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US3302717A
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US3397172A
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US3276206A
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US3336979A
Cited
US3353601A
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US3373814A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-13 | 1974-01-12 | 1974-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-13 | 1978-01-12 | 1978-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-13 | 1982-01-12 | 1982-07-14 | $7700.00 | Window Closed / Lapsed |