US2610953A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl phosphoric acid esters of cellulose and processes for making the same
Assignee: Individual
•
Filing: 1950-04-25
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Granted: 1952-09-16
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Expires: 1970-04-25
Abstract
No abstract record available.
Inventors
- 👤 George C Daul
- 👤 John D Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:41
CPC Classifications
C; C08; C08B; C08B5/00; C08F; C08F8/00; C08F8/40
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
123 words
A PROCESS FOR PREPARING A POLYVINYL PHOSPHORIC ACID ESTER OF CELLULOSE, HAVING ION-EXCHANGE PROPERTIES, WHICH COMPRISES REACTING BY HEATING AN AQUEOUS SOLUTION OF A COMPOUND OF THE GROUP CONSISTING OF POLYVINYL PHOSPHORIC ACID, BEING AN ORTHOPHOSPHORIC ACID ESTER OF POLYVINYL ALCOHOL, WHICH ESTER HAS FREE PHOSPHORIC ACID GROUPS, AND ITS AMMONIUM SALT, WITH CELLULOSE, AT A TEMPERATURE AND FOR A TIME SUFFICIENT TO CAUSE SAID REACTION BUT NOT SO HIGH OR SO LONG AS TO CAUSE SUBSTANTIAL CHARRING AT A TEMPERATURE IN THE RANGE 130* C. TO 160* C. FOR ABOUT 10 TO 30 MINUTES, THEREAFTER COATING SAID REACTION PRODUCT WITH AN AQUEOUS SOLUTION OF A SUBSTANCE TAKEN FROM THE SAID GROUP AND HEATING FOR A TIME SUFFICIENT TO POLYMERIZE SAID COATING SUBSTANCE.
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) | 1955-09-16 | 1956-03-17 | 1956-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-09-16 | 1960-03-17 | 1960-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-09-16 | 1964-03-17 | 1964-09-16 | $7700.00 | Window Closed / Lapsed |