| abstract |
Blocked polyisocyanates with improved water-dispersible or water-soluble properties are prepared by reacting polyisocyanates, in which 50 to 99.8% of the isocyanate groups are blocked, optionally in a solvent-free environment with an organic polyaminosulphonate or an organic polyaminosulphonic acid in sufficient quantities to provide an end product containing from 0.1 to 10%, by weight, of sulphonate groups (SO 3 - ). The blocked polyisocyanates have particular utility when used in combination with hydrophobic polyhydroxyl compounds as binders in aqueous coating compounds. |