US2961439A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dextran ether formaldehyde reaction product
Assignee: Midland Chemical Corp
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Filing: 1954-11-24
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Granted: 1960-11-22
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Expires: 1974-11-24
Abstract
No abstract record available.
Inventors
- 👤 Leo J Novak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:56
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0009; C08B37/0021
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
68 words
A REACTION PRODUCT OF CARBOXYMETHYL DEXTRAN AND FORMALDEHYDE OBTAINED BY MAINTAINING AN AQUEOUS ACIDIC MIXTURE OF CARBOXYMETHYL DEXTRAN CONTAINING AN AVERAGE OF 1.0 TO ABOUT 2.0 CARBOXYMETHYL GROUPS PER ANHYDROGLUCOSE UNIT AND FORMALDEHYDE AT A TEMPERATURE BETWEEN ROOM TEMPERATURE AND 150*C. UNTIL THE FORMALDEHYDE IS REACTED WITH THE CARBOXYMETHYL DEXTRAN AS EVIDENCED BY INCREASED HYDRODURABILITY OF THE PRODUCT AS COMPARED TO THE HYDRODURABILITY OF THE STARTING CARBOXYMETHYL DEXTRAN.
Claim 2
Dependent Claim
68 words
A REACTION PRODUCT OF CARBOXYMETHYL DEXTRAN AND FORMALDEHYDE OBTAINED BY MAINTAINING AN AQUEOUS ACIDIC MIXTURE OF CARBOXYMETHYL DEXTRAN CONTAINING AN AVERAGE OF 1.0 TO ABOUT 2.0 CARBOXYMETHYL GROUPS PER ANHYDROGLUCOSE UNIT AND FORMALDEHYDE AT A TEMPERATURE BETWEEN ROOM TEMPERATURE AND 150*C. UNTIL THE FORMALDEHYDE IS REACTED WITH THE CARBOXYMETHYL DEXTRAN AS EVIDENCED BY INCREASED HYDRODURABILITY OF THE PRODUCT AS COMPARED TO THE HYDRODURABILITY OF THE STARTING CARBOXYMETHYL DEXTRAN.
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) | 1963-11-22 | 1964-05-23 | 1964-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-11-22 | 1968-05-23 | 1968-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-11-22 | 1972-05-23 | 1972-11-22 | $7700.00 | Window Closed / Lapsed |