Production of water-dispersible polyurethanes having ionic groups and hydrophilic side chains
AssigneeBayer Aktiengesellschaft
InventorsKlaus Noll, Jurgen Grammel, Walter Meckel
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Abstract
The present invention relates to water-dispersible polyurethane elastomers having a substantially linear molecular structure, characterized by (a) lateral polyalkylene oxide polyether chains having a content of ethylene oxide units of from about 0.5 to 10% by weight, based on the polyurethane as a whole and (b) a content of .dbd.N.sym..dbd., --COO.crclbar. or --SO.sub.3.crclbar. groups of from about 0.1 to 15 milliequivalents per 100 g, To aqueous dispersions of these water-dispersible polyurethane elastomers and to processes for producing these water-dispersible polyurethane elastomers.
Claims16
Water-dispersible polyurethanes having a substantially linear molecular structure, characterized by:
- (a) lateral polyalkylene oxide polyether chains having a content of laterally incorporated ethylene oxide units sufficient to provided from about 0.5 to 10%, of the weight of the polyurethane as a whole, and,
- (b) a content of .dbd.N.sup..sym. .dbd., --COO.sup..crclbar. or --SO.sub.3.sup..crclbar. groups of from about 0.1 to 15 milliequivalents per 100 g.
A process for the production of a water-dispersible polyurethane having a substantially linear molecular structure comprising reacting
- (a) organic diisocyanates,
- (b) organic difunctional compounds having isocyanatereactive end groups and having a molecular weight of from about 300 to 6000, and
- (c) synthesis components containing hydrophilic groups or groups convertible into hydrophilic groups, said groups responsible for the dispersibility of the polyurethane,
- so as to produce a polyurethane which contains from about 0.5 to 10% by weight of lateral ethylene oxide units, and from about 0.1 to 0.1 to 15 milliequivalents of ionic groups selected from the group consisting .dbd.N.sup..sym. .dbd., --COO.sup..crclbar. and --SO.sub.3.sup..crclbar. per 100 g of polyurethane.
Dependencies are inferred from the claim text.