Powdery, cross-linked polymers which absorb aqueous liquids and blood, method for the production thereof and their use
AssigneeStockhausen GmbH & Co. KG
InventorsRichard Mertens, Jörg Harren
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Abstract
The invention relates to crosslinked polymerizates which are capable of absorbing, which are based on partially neutralized, monoethylenically unsaturated monomers that carry acidic groups, which exhibit improved properties, in particular, with regard to their ability to transport liquids when in a swollen state, and which are subsequently crosslinked on the surface thereof at temperatures ≧150° C. with a combination consisting of polyol used as a subsequent crosslinker compound and of a cation provided in the form of an aqueous solution.
Claims37
A powdered polymer product which has been subjected to secondary crosslinking at its surface, comprising a polymer comprising
- a) 55-99.9 wt.-% of polymerized, ethylenically unsaturated monomers which contain acid groups and are neutralized to at least 25 mole-%,
- b) 0-40 wt.-% of polymerized, ethylenically unsaturated monomers copolymerizable with a),
- c) 0.1-5.0 wt.-% of one or more polymerized crosslinkers,
- d) 0-30 wt.-% of a water-soluble polymer,
- the sum of the weight amounts a) through d) being 100 wt.-%, wherein the polymer has been treated with
- e) 0.01-5 wt.-%, relative to the polymer product, of at least one polyol as surface secondary crosslinking agent in an aqueous solution, and
- f) 0.001-1.0 wt.-%, relative to the polymer product, of a cation in the form of an aqueous solution,
- and heated to a secondary crosslinking temperature of from 150 to 300° C.,
- wherein the powdered polymer product has a permeability of 70×10−7 cm3·s/g or greater.
Dependencies are inferred from the claim text.