Polysaccharide aldehydes prepared by oxidation method and used as strength additives in papermaking
AssigneeNational Starch and Chemical Investment Holding Corporation
InventorsA. Levent Cimedoglu, John S. Thomaides
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Abstract
Polysaccharide aldehydes are prepared using selective oxidation involving the use of nitroxyl radical mediated aqueous oxidation with a limited amount of oxidant and defined reaction conditions. These polysaccharide aldehyde derivatives having maximum effective aldehyde and minimal carboxylic acid levels making them especially useful as wet, temporary wet and dry strength additives for paper.
Claims8
A polysaccharide derivative having C-6 aldehyde and carboxyl functionality wherein the aldehyde to carboxylic acid ratio is greater than or equal to 0.5 based on moles of polysaccharide anhydrosugar unit, wherein the polysaccharide is a starch or a cellulose.
Amphoteric polysaccharide aldehyde derivatives comprising:
- from about 0.5 to about 25 mole % of cationic groups based on moles of polysaccharide anhydrosugar unit,
- from about 1 to about 15 mole % of C-6 aldehyde content based on moles of polysaccharide anhydrosugar unit, and
- from about 0 to about 20 mole % of carboxylic acid content based on moles of polysaccharide anhydrosugar unit,
- wherein the polysaccharide aldehyde derivatives are starch aldehyde derivatives or cellulose aldehyde derivatives.
Dependencies are inferred from the claim text.