Patent US4557311A successfully refreshed from Google Patents.
Patent US3321269A successfully refreshed from Google Patents.
US3321269A
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Process for the production of crystalline calcium carbonate of vaterite type
Assignee: Toagosei Co Ltd
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Filing: 1964-07-07
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Granted: 1967-05-23
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Expires: 1984-07-07
Abstract
No abstract record available.
Inventors
- 👤 Yasui Eizo
- 👤 Shoda Shichiro
- 👤 Suzuki Hiroshi
- 👤 Yamada Hiroshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:11
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/18; C01F11/181; C01P; C01P2002/00; C01P2002/70; C01P2002/72; C01P2004/00; C01P2004/60; C01P2004/61
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
85 words
THE PROCESS FOR PRODUCTION OF CRYSTALLINE CALCIUM CARBONATE OF THE VATERITE TYPE HAVING A MAXIMUM GRAIN SIZE OF 5 MICRONS WHICH COMPRISES THE STEPS OF: (A) VIGOROUSLY AGITATING AN AQUEOUS SOLUTION OF CALCIUM CHLORIDE; (B) REACTING SAID SOLUTION WITH GASEOUS CARBON DIOXIDE DURING THE COURSE OF SAID AGITATING STEP; (C) MAINTAINING THE PH OF SAID SOLUTION AT A MINIMUM VALUE OF 8 SAID REACTING STEP BY THE ADDITION OF AMMONIUM HYDROXIDE; AND (D) MAINTAINING THE REACTION TEMPERTURE IN THE RANGE OF FROM 11* TO 20*C.
Claim 2
Dependent Claim
85 words
THE PROCESS FOR PRODUCTION OF CRYSTALLINE CALCIUM CARBONATE OF THE VATERITE TYPE HAVING A MAXIMUM GRAIN SIZE OF 5 MICRONS WHICH COMPRISES THE STEPS OF: (A) VIGOROUSLY AGITATING AN AQUEOUS SOLUTION OF CALCIUM CHLORIDE; (B) REACTING SAID SOLUTION WITH GASEOUS CARBON DIOXIDE DURING THE COURSE OF SAID AGITATING STEP; (C) MAINTAINING THE PH OF SAID SOLUTION AT A MINIMUM VALUE OF 8 SAID REACTING STEP BY THE ADDITION OF AMMONIUM HYDROXIDE; AND (D) MAINTAINING THE REACTION TEMPERTURE IN THE RANGE OF FROM 11* TO 20*C.
References Cited (Backward Citations)
US2941860A
Cited
US2964382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-05-22 | 1970-11-21 | 1971-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-05-22 | 1974-11-21 | 1975-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-05-22 | 1978-11-21 | 1979-05-23 | $7700.00 | Window Closed / Lapsed |