US3296266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of melamine
Assignee: Honeywell International Inc
•
Filing: 1965-01-21
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Granted: 1967-01-03
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Expires: 1985-01-21
Abstract
No abstract record available.
Inventors
- 👤 Elmer L Nelson
- 👤 Thomas W Kennedy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:00
CPC Classifications
C; C07; C07D; C07D251/00; C07D251/02; C07D251/12; C07D251/26; C07D251/40; C07D251/54; C07D251/62; C07D251/56; C07D251/60; C07D251/70
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
97 words
IN THE PROCESS FOR PURIFYING CRUDE MELAMINE CONTAINING HYDROXY TRIAZINE IMPURITIES BY DIGESTING A DISPERSION OF SAID CRUDE MELAMINE IN AQUEOUS AMMONIA, AT A TEMPERATURE IN THE RANGE 140* TO 230*C., FILTERING THE RESULTING SOLUTION OF MELAMINE IN AQUEOUS AMMONIA AND COOLING THE FILTRATE TO CRYSTALLIZE PURIFIED MELAMINE THEREFROM, THE IMPROVEMENT WHICH COMPRISES COOLING THE SOLUTION OF MELAMINE IN AQUEOUS AMMONIA FIRST TO A TEMPERATURE IN THE RANGE 50* TO 80*C., AND THEN, AFTER A PERIOD OF AT LEAST ONE MINUTE, TO A TEMPERATURE IN THE RANGE 0* TO 40*C., AND RECOVERING THE PURIFIED MELAMINE THUS PRECIPITATED.
Claim 2
Dependent Claim
97 words
IN THE PROCESS FOR PURIFYING CRUDE MELAMINE CONTAINING HYDROXY TRIAZINE IMPURITIES BY DIGESTING A DISPERSION OF SAID CRUDE MELAMINE IN AQUEOUS AMMONIA, AT A TEMPERATURE IN THE RANGE 140* TO 230*C., FILTERING THE RESULTING SOLUTION OF MELAMINE IN AQUEOUS AMMONIA AND COOLING THE FILTRATE TO CRYSTALLIZE PURIFIED MELAMINE THEREFROM, THE IMPROVEMENT WHICH COMPRISES COOLING THE SOLUTION OF MELAMINE IN AQUEOUS AMMONIA FIRST TO A TEMPERATURE IN THE RANGE 50* TO 80*C., AND THEN, AFTER A PERIOD OF AT LEAST ONE MINUTE, TO A TEMPERATURE IN THE RANGE 0* TO 40*C., AND RECOVERING THE PURIFIED MELAMINE THUS PRECIPITATED.
References Cited (Backward Citations)
US3161638A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-01-02 | 1970-07-04 | 1971-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-01-02 | 1974-07-04 | 1975-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-01-02 | 1978-07-04 | 1979-01-03 | $7700.00 | Window Closed / Lapsed |