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US 7,612,016 B2Granted
Preparation of superabsorbent polymers
AssigneeEvonik Stockhausen GmbH
InventorsRichard Mertens, Olaf Höller
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Abstract
The invention describes superabsorbent polymers composed of surface-post crosslinked polycarboxypolysaccharides having excellent age-stable absorption properties, even under load, high attrition resistance and biodegradability and their use for absorbing water, aqueous or serous fluids and also blood. Also disclosed is a method of making which is impervious to changes in raw material quality and which provides consistent product quality.
Claims16
A process for preparing superabsorbent polymers comprising the steps of:
- a) forming a hydrogel by mixing an uncrosslinked polycarboxypolysaccharide with water;
- b) the hydrogel is mechanically comminuted and dried;
- c) the dried hydrogel is comminuted and classified to form a polymer particles;
- and d) the polymer particles are coated with a solution of a crosslinker and subjected to a surface post crosslinking wherein said post crosslinked superabsorbent polymer has an absorbency against pressure (AAP0.7) value of 12.5 g/g or more.
1 more element
Dependencies are inferred from the claim text.