US3639657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Products of acid anhydrides and polyamines used as latent hardeners for epoxy resins
Assignee: Novartis Corp
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Filing: 1969-03-19
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Granted: 1972-02-01
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Expires: 1989-03-19
Abstract
Abstract THE REACTION PRODUCTS OF APPROXIMATELY EQUIMOLECULAR PROPORTIONS OF AN ACID ANHYDRIDE, SUCH AS PHTHALIC ANHYDRIDE, AND A POLYAMINE, SUCH AS DIETHYLENETRIAMINE, ARE LATENE HARDENERS FOR EPOXY RESINS HAVING MORE THAN ONE 1,2-EPOXY GROUPS PER MOLECULE AND, WHEN COMBINED WITH AN EPOXY RESIN, PROVIDE SYSTEMS WHICH ARE STABLE FOR LONG PERIODS WHEN STORES AT AMBIENT OR MODERATELY ELEVATED TEMPERATURES WHILE PROVIDING ON CURING FOR RELATIVELY SHORT PERIODS AT ELEVATED TEMPERATURES, ON THE ORDER OF 100150*C., HARDENED PRODUCTS OF GOOD PROPERTIES.
Inventors
- 👤 Raymond Michael Moran Jr
- 👤 Henry Thomas Belekicki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:55
CPC Classifications
C; C08; C08L; C08L63/00
Claims Analysis
Total Claims: 0
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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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |