Patent US3904684A successfully refreshed from Google Patents.
US3904684A
Expired / Lapsed
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Method for producing sodium citrate dihydrate
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1973-04-19
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Granted: 1975-09-09
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Expires: 1993-04-19
Abstract
Abstract Sodium citrate dihydrate is recovered directly from a citric acid fermentation broth by removing impurities at pH 9 to 13 and concentrating the resulting fluid at pH 10 to 13. The sodium citrate dihydrate is used as food additives, detergent builders as well as desulfurizing agents.
Inventors
- 👤 Masahiko Tsuda
- 👤 Yoshiaki Fujiwara
- 👤 Tetsuya Shiraishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:27
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/40; C12P7/44; C12P7/48; C07; C07C; C07C51/00; C07C51/41; C07C51/412; Y; Y10; Y10S; Y10S435/00; Y10S435/8215; Y10S435/822; Y10S435/83; Y10S435/843; Y10S435/911; Y10S435/921; Y10S435/923; Y10S435/93; Y10S435/94
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
105 words
A METHOD FOR PRODUCING SODIUM CITRATE DIHYDRATE WHICH COMPRISES (1) ADJUSTING A CITRIC ACID FERMENTATION BROTH OBTAINED BY USING A HYDROCARBON AS THE PRINCIPAL CARBON SOURCE FOR THE CULTURE MEDIUM TO A PH FROM 9 TO 13 INCLUSIVE WITH SODIUM HYDROXIDE, SODIUM CARBONATE OR SODIUM HYDROGEN CARBONATE, (2) REMOVING THE INSOLUBLES FROM THE RESULTANT BROTH, (3) CONCENTRATING THE RESULTANT FLUID WHILE MAINTAINING THE FLUID AT A PH FROM 10 TO 13 INCLUSIVE WITH SODIUM HYDROXIDE, SODIUM CARBONATE OR SODIUM HYDROGEN CARBONATE, AND AT A TEMPERATURE OF 50* TO 65*C TO PRECIPITATE SODIUM CITRATE DIHYDRATE CRYSTALS AND (4) RECOVERING THE THUS FORMED CRYSTALS FROM THE FLUID.
Claim 2
Independent Claim
105 words
A METHOD FOR PRODUCING SODIUM CITRATE DIHYDRATE WHICH COMPRISES (1) ADJUSTING A CITRIC ACID FERMENTATION BROTH OBTAINED BY USING A HYDROCARBON AS THE PRINCIPAL CARBON SOURCE FOR THE CULTURE MEDIUM TO A PH FROM 9 TO 13 INCLUSIVE WITH SODIUM HYDROXIDE, SODIUM CARBONATE OR SODIUM HYDROGEN CARBONATE, (2) REMOVING THE INSOLUBLES FROM THE RESULTANT BROTH, (3) CONCENTRATING THE RESULTANT FLUID WHILE MAINTAINING THE FLUID AT A PH FROM 10 TO 13 INCLUSIVE WITH SODIUM HYDROXIDE, SODIUM CARBONATE OR SODIUM HYDROGEN CARBONATE, AND AT A TEMPERATURE OF 50* TO 65*C TO PRECIPITATE SODIUM CITRATE DIHYDRATE CRYSTALS AND (4) RECOVERING THE THUS FORMED CRYSTALS FROM THE FLUID.
Claim 3
Dependent Claim
29 words
The method according to claim 1, wherein the citric acid fermentation broth contains citric acid in the form of its free acid, sodium citrate, ammonium citrate or ions thereof.
References Cited (Backward Citations)
US3086928A
Cited
US3689359A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |