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US 5,672,699 AGranted
Process for preparation of hydrophobic starch derivatives
AssigneeNational Starch and Chemical Investment Holding Corporation
InventorsRobert L. Billmers, Victor L. Mackewicz
Life of this patent
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Abstract
A method for preparing hydrophobic starch derivatives wherein the starch and anhydride reagent are predispersed or intimately contacted by mixing at low acidic pH to form a stable dispersion before being brought to alkaline reaction conditions.
Claims15
A method of preparing a hydrophobic starch derivative comprising reacting starch with an organic acid anhydride in an aqueous system wherein:
- a) starch is slurried in water at an acid pH of less than 7.0,
- b) an organic acid anhydride reagent having the following formula is added to the slurry, ##STR4## where R is a dimethylene or trimethylene group and R' is a hydrocarbon group having 2 to 20 carbon atoms,
- c) intimately contacting the starch and anhydride reagent by mixing to form a stable dispersion, and
- d) adding alkali material to the starch dispersion to adjust the pH to an alkaline pH of greater than 7.0 to initiate the reaction and adding further alkali material to maintain the pH at that level until the reaction is complete.
1 more element
A hydrophobic starch derivative prepared by reacting starch with an organic acid anhydride in an aqueous system wherein:
- a) starch is slurried in water at an acid pH of less than 7.0,
- b) an organic acid anhydride reagent having the following formula is added to the slurry, ##STR5## where R is a dimethylene or trimethylene group and R.sup.1 is a hydrocarbon group having 2 to 20 carbon atoms,
- c) intimately contacting the starch and anhydride reagent by mixing to form a stable dispersion, and
- d) adding alkali material to the starch dispersion to adjust the pH to an alkaline pH of greater than 7.0 to initiate the reaction and adding further alkali material to maintain the pH at that level until the reaction is complete.
1 more element
Dependencies are inferred from the claim text.