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

A process for the preparation of finely divided, porous and rapidly water-swellable polysaccharide graft polymers, comprising:

• adding an aqueous solution, which contains 60 to 95 parts of a 50 to 100 per cent neutralized olefinically unsaturated carboxylic acid, 0 to 50 parts of other olefinically unsaturated monomers, 0 to 2 parts of crosslinking agent and 0.005 to 5 parts of polymerization initiator, continuously at 40.degree. to 100.degree. C. over a time of 0.5 to 5 hours to a suspension, in nonpolar organic solvent, of 5 to 40 parts of polysaccharide and 0 to 2 parts of polymerization initiator wherein said nonpolar organic solvent contains a dispersing agent mixture consisting of
• (a) 50 to 100 per cent by weight of nonionic surfactant having a hydrophilic/lipophilic balance of 0.5 to 10 and
• (b) 0 to 50 per cent by weight of nonionic surfactant having a hydrophilic/lipophilic balance of 10.5 to 20 and thereby conducting semi-continuous reverse phase polymerization;
• partially dehydrating the polymer product obtained in the polymerization step;
• and then
• cross-linking the partially dehydrated polymer in the presence of 0.005 to 5% by weight of crosslinking agent, based on the polymer.