US2818433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making methylenedianilines
Assignee: Monsanto Chemicals Ltd
•
Filing: 1955-09-19
•
Granted: 1957-12-31
•
Expires: 1975-09-19
Abstract
No abstract record available.
Inventors
- 👤 Floyd B Erickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:39
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/68; C07C209/78; C07C209/82; C07C209/84; C07C211/00; C07C211/33; C07C211/39; C07C211/41; C07C211/42; C07C211/43; C07C211/44; C07C211/49; C07C211/50; C07C249/00; C07C249/02; C07C2602/00; C07C2602/02; C07C2602/04; C07C2602/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
66 words
THE METHOD OF PREPARING A 4,4''-METHYLENEDIANILINE WHICH COMPRISES HEATING A SOURCE OF FORMALDEHYDE SELECTED FROM THE GROUP CONSISTING OF FORMALDEHYDE, DIMETHOXY METHANE AND PARAFORMALDEHYDE, WITH MORE THAN A 100% STOICHIOMETRIC EXCESS OF THE HYDROCHLORIC ACID SALT OF A SINGLE ANILINE IN WHICH THE PARA POSITION IS FREE OF SUBSTITUENTS, TO A TEMPERATURE OF 50 TO 90*C. IN AN AQUEOUS MEDIUM, AND RECOVERING THE SAID METHYLENEDIANILINE PRODUCT.
Claim 2
Independent Claim
66 words
THE METHOD OF PREPARING A 4,4''-METHYLENEDIANILINE WHICH COMPRISES HEATING A SOURCE OF FORMALDEHYDE SELECTED FROM THE GROUP CONSISTING OF FORMALDEHYDE, DIMETHOXY METHANE AND PARAFORMALDEHYDE, WITH MORE THAN A 100% STOICHIOMETRIC EXCESS OF THE HYDROCHLORIC ACID SALT OF A SINGLE ANILINE IN WHICH THE PARA POSITION IS FREE OF SUBSTITUENTS, TO A TEMPERATURE OF 50 TO 90*C. IN AN AQUEOUS MEDIUM, AND RECOVERING THE SAID METHYLENEDIANILINE PRODUCT.
References Cited (Backward Citations)
DE58955C
Cited
DE70402C
Cited
DE270663C
Cited
US471659A
Cited
US541859A
Cited
US763756A
Cited
US1803331A
Cited
US2034491A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-12-30 | 1961-07-01 | 1961-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-30 | 1965-07-01 | 1965-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-30 | 1969-07-01 | 1969-12-31 | $7700.00 | Window Closed / Lapsed |