Patent US3919189A successfully refreshed from Google Patents.
US3919189A
Expired / Lapsed
US
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Decreasing bacterial contamination of xanthan gum with propylene oxide
Assignee: Kelco Co
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Filing: 1973-04-09
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Granted: 1975-11-11
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Expires: 1993-04-09
Abstract
Abstract Intimate intermingling, as in a tumble reactor, of particulate xanthan gum with propylene oxide as essentially the only gas present, at about 90*-125* F., for not more than 4 hours, can produce a xanthan gum substantially free of bacterial contaminants; the propylene oxide is removed to afford a residual propylene oxide content of not more than 300 ppm in the product xanthan gum.
Inventors
- 👤 Richard A Empey
- 👤 David J Pettitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:58
CPC Classifications
A; A61; A61L; A61L2/00; A61L2/16; A61L2/20; A61L2/206; A23; A23L; A23L29/00; A23L29/20; A23L29/269; A23L29/27
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
72 words
A PROCESS FOR STERILLIZING XANTHAN GUM CONTAINING ABOUT 24,000 BACTERIA/GM, WHEREIN SAID GUM CHARGE IS TUMBLE-INTERMINGLED WITH ABOUT 1.0 OUNCE PER CUBIC FOOT OF PROPYLENE OXIDE GAS, BASED ON THE REACTOR VOLUME, AS ESSENTIALLY THE ONLY GAS PRESENT, AT ABOUT 105*F. FOR ABOUT 3 HOURS, AND THE PROPYLENE OXIDE GAS IS THEREAFTER REMOVED TO OBTAIN A STERILLIZED XANTHAN GUM PRODUCT HAVNG ABOUT 1,800 BACTERIA/GM. AND ABOUT 18/ PPM OF RESIDUAL PROPYLENE OXIDE.
Claim 2
Dependent Claim
72 words
A PROCESS FOR STERILLIZING XANTHAN GUM CONTAINING ABOUT 24,000 BACTERIA/GM, WHEREIN SAID GUM CHARGE IS TUMBLE-INTERMINGLED WITH ABOUT 1.0 OUNCE PER CUBIC FOOT OF PROPYLENE OXIDE GAS, BASED ON THE REACTOR VOLUME, AS ESSENTIALLY THE ONLY GAS PRESENT, AT ABOUT 105*F. FOR ABOUT 3 HOURS, AND THE PROPYLENE OXIDE GAS IS THEREAFTER REMOVED TO OBTAIN A STERILLIZED XANTHAN GUM PRODUCT HAVNG ABOUT 1,800 BACTERIA/GM. AND ABOUT 18/ PPM OF RESIDUAL PROPYLENE OXIDE.
Claim 3
Dependent Claim
78 words
A process for the purification of xanthan gum containing bacterial contamination which comprises intermingling the particulate impure xanthan gum with gaseous propylene oxide, the latter at a density of 0.4 - 6 ounces per cubic feet; at a temperature of about 95*-115*F. for not more than 4 hours; and recovering the xanthan gum having a bacterial level which is 75% reduced below the original level of contamination, and a propylene oxide residue of no more than 300 ppm.
Claim 4
Dependent Claim
78 words
A process for the purification of xanthan gum containing bacterial contamination which comprises intermingling the particulate impure xanthan gum with gaseous propylene oxide, the latter at a density of 0.4 - 6 ounces per cubic feet; at a temperature of about 95*-115*F. for not more than 4 hours; and recovering the xanthan gum having a bacterial level which is 75% reduced below the original level of contamination, and a propylene oxide residue of no more than 300 ppm.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |