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US 8,133,509 B2Granted
Hydrogels based on aliphatic NCO prepolymers
AssigneeBayer MaterialScience AG
InventorsBurkhard Kohler, Michael Mager, Stefanie Eiden, Johan Kijlstra
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Abstract
The invention concerns novel hydrogels, a process for the preparation of these hydrogels and would contact materials comprising these hydrogels. These polyurethane hydrogels are obtained by the reaction of aliphatic isocyanate prepolymers with polyols comprising tertiary nitrogen in water.
Claims8
A process for producing polyurethane hydrogels comprising mixing:
- a) one or more nonionically hydrophilicized, aliphatic and/or cycloaliphatic polyisocyanate prepolymers which contain less than 1% by weight of monomeric diisocyanates,
- b) one or more compounds having at least one tertiary amino group and at least three hydroxyl groups,
- c) water, and, optionally,
- d) one or more antimicrobially active metal salts and/or metal particles
- wherein said polyisocyanate prepolymers comprise polyoxyalkylene units attached via urethane groups, wherein at least 60 weight % of the oxyalkylene units of said polyoxyalkylene units are oxyethylene units, wherein said oxyethylene units are present in the form of blocks.
2 more elements
Dependencies are inferred from the claim text.