Patent US2997364A successfully refreshed from Google Patents.
US2997364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chrome-tanning mixtures and preparation of leather therewith
Assignee: Bayer AG
•
Filing: 1957-12-02
•
Granted: 1961-08-22
•
Expires: 1977-12-02
Abstract
No abstract record available.
Inventors
- 👤 Komarek Ernst
- 👤 Mauthe Gustav
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:24
CPC Classifications
C; C14; C14C; C14C3/00; C14C3/02; C14C3/28
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
68 words
A PROCESS FOR THE MANUFACTURE OF LEATHER WHICH COMPRISES PRETANNING A HIDE WITH A MIXTURE OF A TRIVALENT CHROMIUM TANNING SALT AND A SYNTHETIC TANNING AGENT PREPARED BY CONDENSATION OF AN UNSULFONATED METHYLOLATED PHENOL WITH A MEMBER OF THE GROUP CONSISTING OF A SULFITE AND A BISULFITE IN THE PRESENCE OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF AN ALCOHOL, ANALDEHYDE, AND A KETONE UNDER ALKALINE CONDITIONS.
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) | 1964-08-21 | 1965-02-20 | 1965-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-21 | 1969-02-20 | 1969-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-21 | 1973-02-20 | 1973-08-22 | $7700.00 | Window Closed / Lapsed |