Patent US3193445A successfully refreshed from Google Patents.
US3193445A
Expired / Lapsed
US
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Method of bleaching cellulosic materials with hydrogen peroxide
Assignee: PPG Industries Inc
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Filing: 1962-07-16
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Granted: 1965-07-06
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Expires: 1982-07-16
Abstract
No abstract record available.
Inventors
- 👤 Walter F Parker
- 👤 Garry L Burroway
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:12
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1036; D06; D06L; D06L4/00; D06L4/10; D06L4/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
48 words
A METHOD OF BLEACHING CELLULOSIC MATERIAL WHICH COMPRISES CONTACTING SAID MATERIAL WITH AQUEOUS HYDROGEN PEROXIDE SOLUTION TO PROVIDE BLEACHED MATERIAL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE AND THEREAFTER TREATING SUCH BLEACHED MATERIAL STILL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE WITH ANHYDRIDE OF 2 TO 8 CARBON CARBOXYLIC ACID.
Claim 2
Independent Claim
48 words
A METHOD OF BLEACHING CELLULOSIC MATERIAL WHICH COMPRISES CONTACTING SAID MATERIAL WITH AQUEOUS HYDROGEN PEROXIDE SOLUTION TO PROVIDE BLEACHED MATERIAL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE AND THEREAFTER TREATING SUCH BLEACHED MATERIAL STILL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE WITH ANHYDRIDE OF 2 TO 8 CARBON CARBOXYLIC ACID.
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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) | 1968-07-05 | 1969-01-04 | 1969-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-07-05 | 1973-01-04 | 1973-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-07-05 | 1977-01-04 | 1977-07-06 | $7700.00 | Window Closed / Lapsed |