US2502330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Washing paper pulp to remove coloring matter
Assignee: Individual
•
Filing: 1943-03-01
•
Granted: 1950-03-28
•
Expires: 1963-03-01
Abstract
No abstract record available.
Inventors
- 👤 Clarence E Libby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:01
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1042
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
IN THE PROCESS OF REMOVING ORGANIC COLORING MATTER IN THE NATURE OF TANNIN OR LIGNIN COMPOUNDS FROM PAPER PULP WITHOUT REMOVING A SUBSTANTIAL AMOUNT OF CELLULOSE CONSTITUENT OF THE PULP, THE STEP COMPRISING WASHING THE PULP AFTER DIGESTION BUT BEFORE BLEACHING WITH A SOLUTION CONSISTING ESSENTIALLY OF WATER AND ABOUT 20 TO 100 PARS OF MOLECULARLY DEHYDRATED ALKALL METAL PHOSPATE PER ONE MILLION PARTS OF WATER, THE CONCENTRATION OF MOLECULARLY DEHYDRATED ALKALI METAL PHOSPHATE IN THE WASH WATER BEING SUBSTANTIALLY LESS THAN THAT WHICH WOULD BE REQUIRED TO SOFTEN THE WATER BY SEQUESTRATION OF CALCIUM.
Claim 2
Dependent Claim
95 words
IN THE PROCESS OF REMOVING ORGANIC COLORING MATTER IN THE NATURE OF TANNIN OR LIGNIN COMPOUNDS FROM PAPER PULP WITHOUT REMOVING A SUBSTANTIAL AMOUNT OF CELLULOSE CONSTITUENT OF THE PULP, THE STEP COMPRISING WASHING THE PULP AFTER DIGESTION BUT BEFORE BLEACHING WITH A SOLUTION CONSISTING ESSENTIALLY OF WATER AND ABOUT 20 TO 100 PARS OF MOLECULARLY DEHYDRATED ALKALL METAL PHOSPATE PER ONE MILLION PARTS OF WATER, THE CONCENTRATION OF MOLECULARLY DEHYDRATED ALKALI METAL PHOSPHATE IN THE WASH WATER BEING SUBSTANTIALLY LESS THAN THAT WHICH WOULD BE REQUIRED TO SOFTEN THE WATER BY SEQUESTRATION OF CALCIUM.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-03-27 | 1953-09-26 | 1954-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-03-27 | 1957-09-26 | 1958-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-03-27 | 1961-09-26 | 1962-03-28 | $7700.00 | Window Closed / Lapsed |