Patent US6217549B1 successfully refreshed from Google Patents.
US2668153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a sponge material and the product resulting therefrom
Assignee: Individual
•
Filing: 1951-04-28
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Granted: 1954-02-02
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Expires: 1971-04-28
Abstract
No abstract record available.
Inventors
- 👤 Hammon Henry George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:21
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/30; C08J2329/00; C08J2329/14; Y; Y10; Y10S; Y10S264/00; Y10S264/13
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
103 words
A SPONGE MATERIAL COMPRISING THE REACTION PRODUCT OF POLUVINYL ALCOHOL AND FORMALDEHYDE IN WHICH THE MAJOR PORTION OF THE MATERIAL HAS FROM ABOUT 35 TO 80% OF THE HYDROXYL GROUPS OF THE POLYVINYL ALCOHOL REACTED, AND CONTAINING LOCALIZED RELATIVELY HARD SECTIONS OF SMALL EXTENT IN WHICH A HIGHER PERCENTAGE OF HYDROXYL GROUPS ARE REACTED THAN ARE REACTED IN THE REMAINDER OF THE SPONGE MATERIAL, SAID HARD SECTIONS BEING FORMED BY REACTING THE POLYVINYL ALCOHOL WITH GRANULAR PARAFORMALDEHYDE SUBSTANTIALLY ALL THE PARTICLES OF WHICH HAVE A MAXIMUM SIZE OF ABOUT 20 MESH AND IN WHICH SUBSTANTIALLY NO PARTICLES ARE ABOVE 8 MESH IN SIZE.
Claim 2
Dependent Claim
103 words
A SPONGE MATERIAL COMPRISING THE REACTION PRODUCT OF POLUVINYL ALCOHOL AND FORMALDEHYDE IN WHICH THE MAJOR PORTION OF THE MATERIAL HAS FROM ABOUT 35 TO 80% OF THE HYDROXYL GROUPS OF THE POLYVINYL ALCOHOL REACTED, AND CONTAINING LOCALIZED RELATIVELY HARD SECTIONS OF SMALL EXTENT IN WHICH A HIGHER PERCENTAGE OF HYDROXYL GROUPS ARE REACTED THAN ARE REACTED IN THE REMAINDER OF THE SPONGE MATERIAL, SAID HARD SECTIONS BEING FORMED BY REACTING THE POLYVINYL ALCOHOL WITH GRANULAR PARAFORMALDEHYDE SUBSTANTIALLY ALL THE PARTICLES OF WHICH HAVE A MAXIMUM SIZE OF ABOUT 20 MESH AND IN WHICH SUBSTANTIALLY NO PARTICLES ARE ABOVE 8 MESH IN SIZE.
References Cited (Backward Citations)
GB573966A
Cited
US2609347A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-02-01 | 1957-08-03 | 1958-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-02-01 | 1961-08-03 | 1962-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-02-01 | 1965-08-03 | 1966-02-02 | $7700.00 | Window Closed / Lapsed |