US3661510A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light bulk density sodium perborate
Assignee: FMC Corp
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Filing: 1969-03-13
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Granted: 1972-05-09
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Expires: 1989-03-13
Abstract
Abstract A light, bulk density (about 0.3-0.6 g./cc.) sodium perborate having a particle size larger than about 60 mesh is produced by reacting together an aqueous sodium metaborate solution with hydrogen peroxide in the presence of externally prepared, prismatic, seed crystals of sodium perborate tetrahydrate.
Inventors
- 👤 Donald Charles Winkley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:20
CPC Classifications
C; C01; C01B; C01B15/00; C01B15/055; C01B15/12; C01B15/126
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
Process of producing sodium perborate in the form of prismatic crystals having a length:width ratio of 3:1 to 10:1, said crystals being radially clustered about a common center in a ''''star''''-shaped cluster having a size larger than 60 mesh and a bulk density of 0.3- 0.6 g./cc. which comprises reacting together at 25* - 45* C., in an aqueous medium, hydrogen peroxide and sodium metaborate in a mole ratio of H2O2:BO2 of 1:1 in the presence of externally prepared, preformed seed crystals of sodium perborate tetrahydrate having a smaller size than the desired product and a length:width ratio of at least 3:1 and separating the resultant sodium perborate crystals from their mother liquor.
Claim 2
Dependent Claim
39 words
Process of claim 2 wherein the hydrogen peroxide is added as an aqueous solution having a concentration of 30- 70 percent hydrogen peroxide and the sodium metaborate is added as an aqueous solution containing about 5 M sodium metaborate.
Claim 3
Dependent Claim
31 words
Process of claim 2 wherein the process is carried out in a vacuum crystallizer and water is constantly evaporated from the reaction solution to maintain the volume of the solution constant.
Claim 4
Dependent Claim
37 words
Process of claim 2 wherein the seeding rate is maintained from 5 to 30 percent and the sodium perborate ''''star''''-shaped crystals are prepared at a rate of between 50- 300 g./hr. per liter of active crystallizer volume.
Claim 5
Dependent Claim
26 words
Process of claim 2 wherein the reaction takes place in the presence of 15- 30 g./l. of excess sodium metaborate and 5- 7 g./l. of borax.
Claim 6
Dependent Claim
16 words
Process of claim 2 wherein the slurry density of the reaction mixture is from 5- 40.
References Cited (Backward Citations)
US2223903A
Cited
US2257461A
Cited
US2828183A
Cited
US2947602A
Cited
US3348907A
Cited
FR1436629A
Cited
GB1142304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |