Patent ID: 9650742
Date: 2017-05-16
CPC Classifications: C08B,C08L,D21C,D21H

Claim:
1. A process for making a hydrogel forming material from a kraft or sulfite pulping process cellulosic pulp slurry consisting essentially of: extracting hemicellulose heteropolymers from the kraft or sulfite pulping process cellulosic pulp slurry as a hemicaustic extract by treating the cellulosic pulp slurry with a cold caustic solution; isolating the hemicaustic extract, wherein the hemicaustic extract comprises 2% by weight to 12% by weight hemicellulose heteropolymers and 2% to 8% by weight of caustic; concentrating the hemicaustic extract to 5% by weight to 15% by weight hemicellulose heteropolymers and about 3% by weight to about 20% by weight of caustic compounds by nanofiltration; preparing a heterogeneous reaction mixture comprised of the hemicaustic extract and a derivatizing agent comprised of a monofunctional etherifying agent and/or a polyfunctional organic cross-linking agent; and raising the temperature of the reaction mixture to a temperature from about 50° C. to the boiling point of the reaction mixture for a time period sufficient to react the hemicaustic extract and the derivatizing agent and producing a reaction product comprising a hydrogel forming material.