Process for the peparation of finely divided, water-swellable polysaccharide graft polymers

In a process for the preparation of finely divided, porous and rapidly water-swellable polysaccharide graft polymers, comprising the steps of semicontinuous reverse-phase suspension polymerization, partial dewatering and crosslinking, the improvement being that during the suspension polymerization step,

• an aqueous solution containing from 60 to 95 parts of an olefinically unsaturated carboxylic acid which has been neutralized to the extent of from 50 to 100%,
• from 0 to 50 parts of at least one other olefinically unsaturated monomer,
• from 0 to 2 parts of crosslinking agent and
• from 0.005 to 5 parts of polymerization initiator, is added continuously at from 40.degree. to 100.degree. C. over the course of from 0.5 to 5 hours to a suspension of from 5 to 40 parts of polysaccharide and from 0 to 2 parts of polymerization initiator in a nonpolar organic solvent which contains 1 to 10% by weight, based on the total weight of said olefinically unsaturated carboxylic acid, of a dispersant mixture of
• (a) from 50 to 100% by weight of nonionic surfactant having a hydrophilic-lipophilic balance of 0.5 to 10, and
• (b) from 0 to 50% by weight of nonionic surfactant having a hydrophilic-lipophilic balance of from 10.5 to 20, and wherein,
• after from 75 to 100% of the aqueous monomer containing solution has been added, 0.2 to 4% by weight, based on the total weight of said olefinically unsaturated carboxylic acid, of an additional dispersant selected from the group consisting of an amphoteric ammonium compound containing an alkyl radical having 6 to 20 carbon atoms, a quaternary imidazolinium salt containing an alkyl radical having 6 to 20 carbon atoms, and mixtures thereof is added.