Patent US4070535A successfully refreshed from Google Patents.
US4070535A
Expired / Lapsed
US
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Cellulase-free xanthan gum and process for producing same
Assignee: Merck and Co Inc
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Filing: 1975-08-22
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Granted: 1978-01-24
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Expires: 1995-08-22
Abstract
Abstract Intimate intermingling, as in a tumble reactor, of wet particulate xanthan gum, with either propylene oxide, beta -propiolactone, glutaraldehyde or pivalolactone, as essentially the only gas present, at about 40 DEG -70 DEG C., for from 1-5 hours, produces xanthan gum in which the cellulase enzyme is inactivated, but in which the viscosity of solutions is increased; 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
2026-11-03 06:48
CPC Classifications
C; C12; C12N; C12N9/00; C12N9/99; C08; C08B; C08B37/00; C08B37/0006; C08B37/0024; C08B37/0033
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
93 words
A process for inactivating cellulase enzyme in xanthan gum precipitated from a fermentation beer at a pH of from about 4 to about 8 comprising intermingling wet particulate chemically unmodified xanthan gum, having a solids content not above about 90% by weight, with 2-20% based on xanthan dry weight of an oxide reagent which is either propylene oxide, B-propiolactone, glutaraldehyde, pivalolactone, glycidol, epichlorohydrin or ethylene oxide at from about 40° to about 70° C., for from about 1 to about 5 hours, at ambient pressure and recovering the cellulase-inactivated xanthan gum thus produced.
Claim 2
Dependent Claim
93 words
A process for inactivating cellulase enzyme in xanthan gum precipitated from a fermentation beer at a pH of from about 4 to about 8 comprising intermingling wet particulate chemically unmodified xanthan gum, having a solids content not above about 90% by weight, with 2-20% based on xanthan dry weight of an oxide reagent which is either propylene oxide, B-propiolactone, glutaraldehyde, pivalolactone, glycidol, epichlorohydrin or ethylene oxide at from about 40° to about 70° C., for from about 1 to about 5 hours, at ambient pressure and recovering the cellulase-inactivated xanthan gum thus produced.
Claim 3
Dependent Claim
31 words
The process of claim 1 wherein the temperature is from about 50° to about 70° C. and the amount of oxide reagent is from about 4-12% based on xanthan dry weight.
Claim 4
Dependent Claim
23 words
The process of claim 2 wherein the amount of oxide reagent is from about 8 to about 12% based on xanthan dry weight.
Claim 5
Dependent Claim
12 words
The process of claim 1 in which oxide reagent is propylene oxide.
Claim 6
Dependent Claim
23 words
The process of claim 1 in which the produced xanthan gum has a residual propylene oxide content of less than about 300 ppm.
Claim 7
Dependent Claim
28 words
The process of claim 1 in which the wet particulate xanthan gum contains 50-60% xanthan gum solids, the rest of the weight being water or water and isopropanol.
Claim 8
Dependent Claim
9 words
The product prepared by the process of claim 1.
Claim 9
Dependent Claim
23 words
The process of claim 1 in which the produced xanthan gum has a residual propylene oxide content of less than about 180 ppm.
Claim 10
Dependent Claim
17 words
A process according to claim 1 wherein the oxide reagent is propylene oxide, β-propiolactone, glutaraldehyde or pivalolactone.
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) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |