Polysaccharide derivatives containing aldehyde groups, their preparation from the corresponding acetals and use in paper

Abstract From the Canadian patent

Polysaccharide aldehydes having the formula (I) or Sacch-O-CH2-Ar-CHO (II) such as starch, cellulose, and gum aldehydes, are useful as paper additives for imparting strength and as the granular or gelatinized portion of a corrugating adhesive. Those having formula I are prepared by a nonoxidative method which involves reacting the polysaccharide base in the, presence of alkali, with a derivatizing acetal reagent having the general structure , and then hydrolyzing the acetal by adjusting the pH to less than 7, preferably 2-4. In the formula Ar is an aryl group, optionally containing an ether linkage or an alkaryl group and A, and A' are lower alkyls or together form at least a 5-membered …