Patent US3257418A successfully refreshed from Google Patents.
US3257418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dianhydride and process of preparation
Assignee: EIDP Inc
•
Filing: 1964-12-23
•
Granted: 1966-06-21
•
Expires: 1984-12-23
Abstract
No abstract record available.
Inventors
- 👤 George B Vermont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:50
CPC Classifications
C; C07; C07D; C07D493/00; C07D493/02; C07D493/08; C08; C08G; C08G73/00; C08G73/06; C08G73/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
5 words
TRICYCLO (4.2.2.0**2,5) - 7-DECENE-4-PHENYL-3,9,10-TRICHLORO-3,4,9,10-TETRACARBOXYLIC DIANHYDRIDE.
Claim 2
Dependent Claim
5 words
TRICYCLO (4.2.2.0**2,5) - 7-DECENE-4-PHENYL-3,9,10-TRICHLORO-3,4,9,10-TETRACARBOXYLIC DIANHYDRIDE.
Claim 3
Dependent Claim
77 words
A PROCESS FOR MAKING THE COMPOUND OF CLAIM 1 WHICH CONSISTS ESSENTIALLY OF A. REACTING TWO MOLECULES OF DICHLOROMALEIC ANHYDRIDE WITH TWO MOLECULUES OF BENZENE BY EXPOSING TO RADIANT ENERGY CONSISTING ESSENTIALLY OF WAVELENGTHS OF 2700 TO 4000 ANGSTROM UNITS A SOLUTION OF (1) DICHLOROMALEIC ANHYDRIDE, (2) BENZENE AND (3) A PHOTOSENSITIZER CONSISTING ESSENTIALLY OF AN AROMATIC COMPOUND HAVING A CARBONYL GROUP ATTACHED TO THE RING, AND B. SEPARATING THE RESULTING DIANHYDRIDE FROM THE REACTION PRODUCT MIXTURE.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-06-20 | 1969-12-20 | 1970-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-06-20 | 1973-12-20 | 1974-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-06-20 | 1977-12-20 | 1978-06-21 | $7700.00 | Window Closed / Lapsed |