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US4048434A
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Method for preparing an acid modified oxidized hydroxyalkyl starch
Assignee: Standard Brands Inc
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Filing: 1975-05-29
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Granted: 1977-09-13
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Expires: 1995-05-29
Abstract
Abstract Acid modified oxidized hydroxyalkyl starch is prepared by the sequential steps of: (a) reacting granular starch with a 1,2-alkylene epoxide under conditions whereby starch having a hydroxyalkyl D of S of from about 0.02 to less than about 0.18 is obtained and the granular nature of the starch is maintained, (b) oxidizing the hydroxyalkyl starch with an alkaline hypochlorite under suitable conditions to introduce an amount of carboxylic groups onto said starch, the amount being no greater than about 1.2 minus the product of 7 times the hydroxyalkyl D of S, (c) treating the oxidized hydroxyalkyl starch with an acid to increase the alkaline paste fluidity thereof, and (d) recovering the resulting product.
Inventors
- 👤 Edwin L. Speakman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:44
CPC Classifications
C; C08; C08B; C08B31/00; C08B31/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
239 words
A method for preparing a gelatinizable acid modified oxidized hydroxyalkyl starch by the sequential steps consisting essentially of: a. reacting granular starch with a 1,2-alkylene epoxide containing 2 to 4 carbon atoms, inclusively, under non-gelatinizing conditions at a pH of above about 10 to obtain a granular starch having a hydroxyalkyl D of S of from about 0.02 to less than about 0.18, b. adjusting the pH of the hydroxyalkyl starch to a range of from about 6 to about 8, c. oxidizing the hydroxyalkyl starch with an alkaline hypochlorite under conditions to introduce an amount of carboxylic groups onto said starch, the amount of carboxylic groups, percent by weight dry starch basis, being no greater than about 1.2 minus the product of 7 times the hydroxyalkyl D of S. d. treating the hydroxyalkyl oxidized starch with an acid to increase the alkaline paste fluidity thereof, said treatment being carried out under conditions such that 1. the starch having a D of S of from about 0.02 to about 0.1 has an alkaline paste fluidity of less than about 293, 2. the starch having a D of S of from about 0.11 to about 0.13 has an alkaline paste fluidity of less than about 283, and 3. the starch having a D of S of from about 0.14 to less than about 0.18 has an alkaline paste fluidity of less than about 210, and e. recovering the resulting product.
Claim 2
Independent Claim
239 words
A method for preparing a gelatinizable acid modified oxidized hydroxyalkyl starch by the sequential steps consisting essentially of: a. reacting granular starch with a 1,2-alkylene epoxide containing 2 to 4 carbon atoms, inclusively, under non-gelatinizing conditions at a pH of above about 10 to obtain a granular starch having a hydroxyalkyl D of S of from about 0.02 to less than about 0.18, b. adjusting the pH of the hydroxyalkyl starch to a range of from about 6 to about 8, c. oxidizing the hydroxyalkyl starch with an alkaline hypochlorite under conditions to introduce an amount of carboxylic groups onto said starch, the amount of carboxylic groups, percent by weight dry starch basis, being no greater than about 1.2 minus the product of 7 times the hydroxyalkyl D of S. d. treating the hydroxyalkyl oxidized starch with an acid to increase the alkaline paste fluidity thereof, said treatment being carried out under conditions such that 1. the starch having a D of S of from about 0.02 to about 0.1 has an alkaline paste fluidity of less than about 293, 2. the starch having a D of S of from about 0.11 to about 0.13 has an alkaline paste fluidity of less than about 283, and 3. the starch having a D of S of from about 0.14 to less than about 0.18 has an alkaline paste fluidity of less than about 210, and e. recovering the resulting product.
Claim 3
Dependent Claim
32 words
A method for preparing a gelatinizable oxidized hydroxyalkyl starch as defined in claim 1, wherein the granular starch is reacted with a 1,2-alkylene epoxide in the presence of a starch gelatinization inhibitor.
Claim 4
Dependent Claim
21 words
A method for preparing a gelatinizable oxidized hydroxyalkyl starch as defined in claim 2, wherein the 1,2-alkylene epoxide is ethylene oxide.
Claim 5
Dependent Claim
23 words
A method for preparing a gelatinizable oxidized hydroxyalkyl starch as defined in claim 3, wherein the alkaline hypochlorite is sodium or potassium hypochlorite.
Claim 6
Dependent Claim
21 words
A method for preparing a gelatinizable oxidized hydroxyalkyl starch as defined in claim 4, wherein the granular starch is corn starch.
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) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |