The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 08, 1991
Filed:
Dec. 28, 1988
John J Tsai, Belle Mead, NJ (US);
Patrick G Jobe, Westfield, NJ (US);
Diane J Lamb, Lincoln, NE (US);
Robert L Billmrs, Stockton, NJ (US);
Martin M Tessler, Edison, NJ (US);
National Starch and Chemical Investment Holding Corporation, Wilmington, DE (US);
Abstract
Polysaccharide aldehydes having the formula Sacch--O--CH.sub.2 --CH.dbd.CH--CHO, Saach--O--CH.sub.2 --C.tbd.C--CHO, ##STR1## starch, cellulose, and gum aldehydes, are useful for imparting wet, dry, or temporary wet strength to paper. They are prepared by a non-oxidative method which involves reacting the polysaccharide base, in the presence of alkali, with a derivatizing acetal reagent having the general structure ##STR2## and then hydrolyzing the acetal by adjusting the pH to less than 7, preferably 2-4. In the formulas, n is 1-3; R.sup.11 and R.sup.12 are independently an alkyl, aryl, aralkyl, or alkaryl group when n is 1, R.sup.11 or R.sup.12 is one of the groups when n is 2, or R.sup.11 and R.sup.12 are not present when n is 3; R.sup.13 is an alkyl group, optionally containing an ether linkage, or an aralkyl group; R.sup.14 and R.sup.15 are individually a hydrogen or a methyl group; R.sup.16, R.sup.17, and R.sup.18 are individually an alkyl group; Y.sup.- is an anion; Z is an organic group capable of reacting with the polysaccharide base to form an ether derivative and selected from the group consisting of an epoxide, ethylenically unsaturated group, halohydrin, and halogen; R.sup.19, if present, is a divalent organic group containing no reactive substiuents; and A and A' are lower alkyls or together form at least a 5-membered cyclic acetal.