Bayer Aktiengesellschaft

Sergej Schapowalow

Siegfried Korte

Rolf-Volker Meyer

Gunter Sackmann

Klaus Szablikowski

Martin Ullrich

Wolfgang Koch

Helmut Brod

G Unter Sackmann

Gu/ Nter Sackmann

Super-absorbent polymer in the form of pre-formed spherical particles obtainable by alkaline hydrolysis of aqueous emulsions of crosslinked and/or un-crosslinked homopolymers and/or copolymers of acrylonitrile in water/alcohol mixtures and the use of the polymer in hygiene products, as a water-storing material in agriculture and for the sheathing of electrical cables.

Pre-formed super absorbers with high swelling capacity

A process for the continuous production of superabsorbent polymers, characterised in that aqueous emulsions of uncross-linked and cross-linked polyacrylonitrile homopolymers and/or copolymers, the polyacrylonitrile concentrations in the reaction mixture being from 10 to 45 w.t. %, are hydrolysed with aqueous alkali hydroxide solutions at 50.degree. to 100.degree. C. in a continuously operating reactor suitable for carrying out highly viscous reactions, and that from the highly viscous gels formed the products in the form of superabsorbent powders are continuously precipitated by means of continuous precipitation using low-boiling monoalcohols, and the use thereof in sanitary articles, as water-storing materials in agriculture or for sheathing electrical cables.

Process for the continuous production of superabsorbent polymers from

Superabsorbent polymers based on partly hydrolysed homopolymers and/or copolymers of acrylonitrile which are cross-linked through the incorporation of polyfunctional monomers, wherein 30 to 80 mol-% of the nitrile groups are converted into carboxylate groups, 20 to 70 mol-% of the nitrile groups are converted into carbonamide groups and 0 mol-% to 20 mol-% of the nitrile groups are unchanged, and the said cross-linked polymers possess a swelling capacity of 700 g/g in water and of up to 60 g/g in physiological saline and a gel strength of from 20 g to 100 g, their preparation and their use.

Superabsorbent polymers from cross-linked polyacrylonitrile emulsions

A process for the production of super-absorbent polymers with a swelling capacity in water-containing liquids of up to 1,000 g/g in which aqueous emulsions of particularly high molecular weight polymers of acrylonitrile are partly hydrolyzed by reaction with aqueous solutions of alkali metal and/or alkaline earth metal hydroxides, the polymers are precipitated in powder form by addition of water-miscible organic solvents, separated off, dried and then optionally heated for a short time. The super-absorbent polymers are used as water-storing materials, for example in sanitary articles, in agriculture or in the sheathing of electrical cables.

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Leverkusen, Germany

Sergej Schapowalow