US3825656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing hexagonal system prismatic calcium sulfite
Assignee: Lion Fat and Oil Co Ltd
•
Filing: 1971-12-16
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Granted: 1974-07-23
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Expires: 1991-12-16
Abstract
Abstract HEXAGONAL SYSTEM PRISMATIC CALCIUM SULFITE, WHICH IS USEFUL AS A FILLER FOR THERMOPLASTIC RESINS, IN PREPARED BY CONTACTIG AN SO2-CONTAINING GAS WITH A SUSPENSION OF CALCIUM HYDROXIDE, PRECIPITATED CALCIUM CARBONATE, OR MIXTURES THEREOF WHEREIN THE SO2-CONTAINING GAS IS PASSED CONTINUOUSLY THROUGH A PLURALITY OF CONTACT ZONES IN WHICH THE FIRST OF SAID ZONES HAS A TEMPERATURE OF 50*-100*C. AND A PH OF 3-6 AND EACH SUCCEEDING CONTACT ZONE HAS A TEMPERATURE OF 50*-100*C. AND A PH OF HIGHER THAN 6, WHILE SIMULTANEOUSLY PASSING THE SUSPENSION THROUGH SAID PLURALITY OF CONTACT ZONES COUNTER-CURRENTLY TO THE DIRECTION OF THE FLOW OF THE SO2-CONTAINING GAS.
Inventors
- 👤 M Hirakawa
- 👤 R Susuki
- 👤 K Murakami
- 👤 H Hoshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:58
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/48
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) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |