Patent US4233283A successfully refreshed from Google Patents.
US4233283A
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Method for manufacture of iron oxide flakes
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1979-03-15
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Granted: 1980-11-11
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Expires: 1999-03-15
Abstract
Abstract In the manufacture of iron oxide flakes by the steps of mixing an aqueous ferric salt solution with an aqueous alkali solution for thereby inducing an amorphous precipitate and subjecting the precipitate to a hydrothermal treatment, iron oxide flakes of an increased flake size are obtained by adding boric acid or a salt thereof to the mixture prior to the step of hydrothermal treatment.
Inventors
- 👤 Kazuaki Ado
- 👤 Soichiro Nobuoka
- 👤 Takashi Asai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:27
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/22; C09C1/24; C01; C01G; C01G49/00; C01G49/02; C01G49/06; C01P; C01P2002/00; C01P2002/80; C01P2002/84; C01P2004/00; C01P2004/20; C01P2004/22; C01P2004/51; C01P2004/52; C01P2004/54; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/32; C01P2006/60; C01P2006/80
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
92 words
In a method for the manufacture of micaceous α-iron oxide by the steps of mixing an aqueous ferric salt solution with an aqueous alkali solution thereby producing an amorphous precipitate and subjecting the precipitate to a hydrothermal treatment at a temperature of more than 150° C. under pressure of more than 5 kg/cm 2 , the improvement which comprises the step of adding boric acid or a salt thereof in an amount of 0.1 to 10% by weight, based on the ferric salt computed as an anhydride, prior to the hydrothermal treatment.
Claim 2
Dependent Claim
92 words
In a method for the manufacture of micaceous α-iron oxide by the steps of mixing an aqueous ferric salt solution with an aqueous alkali solution thereby producing an amorphous precipitate and subjecting the precipitate to a hydrothermal treatment at a temperature of more than 150° C. under pressure of more than 5 kg/cm 2 , the improvement which comprises the step of adding boric acid or a salt thereof in an amount of 0.1 to 10% by weight, based on the ferric salt computed as an anhydride, prior to the hydrothermal treatment.
Claim 3
Dependent Claim
21 words
The method according to claim 1, wherein boric acid or a salt thereof is added to the aqueous ferric salt solution.
Claim 4
Dependent Claim
20 words
The method according to claim 1, wherein boric acid or a salt thereof is added to the aqueous alkali solution.
Claim 5
Dependent Claim
19 words
The method according to claim 1, wherein boric acid or a salt thereof is added to the amorphous precipitate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |