US3364235A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phthalic anhydride color inhibition
Assignee: Sherwin Williams Co
•
Filing: 1966-01-03
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Granted: 1968-01-16
•
Expires: 1986-01-03
Abstract
No abstract record available.
Inventors
- 👤 Thomas A Bloom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:32
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/573
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
87 words
A PROCESS FOR INHIBITING COLOR FORMATION IN MOLTEN DISTILLED PHTHALIC ANHYDRIDE WHICH COMPRISES ADDING TO CRUDE PHTHALIC ANHYDRIDE WHICH IS PREPARED BY A CONVENTIONAL PROCESS OF OXIDIZING NAPHTHALENE, A COLOR INHIBITOR FROM THE CLASS CONSISTING OF CALCIUM, BARIUM, ZINC, CADMIUM, SILVER AND LEAD, AND OXIDES THEREOF, IN AN AMOUNT OF A FRACTION OF ONE PERCENT EFFECTIVE TO INHIBIT COLOR FORMATION WHEN THE PHTHALIC ANHYDRIDE IS DISTILLED, AND THEREAFTER DISTILLING THE PHTHALIC ANHYDRIDE WHILE SAID COLOR INHIBITOR IS PRESENT IN THE MOLTEN PHTHALIC ANHYDRIDE BEING SUBJECTED TO DISTILLATION.
Claim 2
Dependent Claim
87 words
A PROCESS FOR INHIBITING COLOR FORMATION IN MOLTEN DISTILLED PHTHALIC ANHYDRIDE WHICH COMPRISES ADDING TO CRUDE PHTHALIC ANHYDRIDE WHICH IS PREPARED BY A CONVENTIONAL PROCESS OF OXIDIZING NAPHTHALENE, A COLOR INHIBITOR FROM THE CLASS CONSISTING OF CALCIUM, BARIUM, ZINC, CADMIUM, SILVER AND LEAD, AND OXIDES THEREOF, IN AN AMOUNT OF A FRACTION OF ONE PERCENT EFFECTIVE TO INHIBIT COLOR FORMATION WHEN THE PHTHALIC ANHYDRIDE IS DISTILLED, AND THEREAFTER DISTILLING THE PHTHALIC ANHYDRIDE WHILE SAID COLOR INHIBITOR IS PRESENT IN THE MOLTEN PHTHALIC ANHYDRIDE BEING SUBJECTED TO DISTILLATION.
References Cited (Backward Citations)
US2510852A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-01-15 | 1971-07-17 | 1972-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-01-15 | 1975-07-17 | 1976-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-01-15 | 1979-07-17 | 1980-01-16 | $7700.00 | Window Closed / Lapsed |