Process and equipment for preparing swellable cross-linked carboxyalkylcelluloses from natural cellulose or cellulose hydrate and use thereof

A process for preparing swellable cross-linked carboxyalkylcelluloses by reacting cellulose, a carboxyalkylating etherifying agent, and a cross-linking agent in an aqueous alkaline medium, comprising effecting alkalizing, etherifying, and cross-linking simultaneously in one reaction step using fibers, textile sheet materials containing these fibers having a base of cellulose hydrate or of natural cellulose, or sheet materials from the group of films and sponge cloths composed of cellulose hydrate, by contacting

• (a) said fibers or sheet materials with an ample quantity of an aqueous alkaline reaction mixture,
• (b) removing part of the reaction mixture from the fibers or sheet materials contacted therewith, so that at least the quantity required for reaction is still present, wherein the molar relationships of the components of said quantity of the reaction mixture ranges, relative to 1 mole of cellulose, from 0.7 to 2.1 moles of alkali hydroxide, 10 to 30 moles of H.sub.2 O, 0.7 to 2 moles of the etherifying agent and 0.005 to 0.1 mole of the cross-linking agent, and
• (c) treating the fibers or sheet materials containing said remainder of the aqueous alkaline reaction mixture with heat energy for the purpose of the actual chemical reaction.