| 摘要 |
<p>Preparing water emulsifiable polyisocyanate preparation, comprises (a) preparing a dispersing-active product from at least a diisocyanate comprising e.g. hexamethylene diisocyanate, 2,4- and 2,6-toluene diisocyanate, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, or 2,4'- and 4,4'-diisocyanatodiphenylmethane with at least a mono- or polyhydric 2-4C-polyalkyleneetheralcohol in the alkylene groups, which includes a polyether chain with at least 8 ethylene oxide units, and (b) mixing the resulting reaction product of step (a) with at least one (cyclo)aliphatic polyisocyanate. Preparing water emulsifiable polyisocyanate preparation, comprises (a) preparing a dispersing-active product from at least a diisocyanate comprising hexamethylene diisocyanate, 4,4'-di-(isocyanatocyclohexyl) -methane, 1-isocyanato-3,3,5-trimethyl-5-(isocyanatomethyl)cyclohexa ne, 2,4- and 2,6-toluene diisocyanate, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, or 2,4'- and 4,4'-diisocyanatodiphenylmethane with at least a mono- or polyhydric 2-4C-polyalkyleneetheralcohol in the alkylene groups, which includes at least 8 ethylene oxide units containing polyether chain, and (b) mixing the resulting reaction product of step (a) with at least one (cyclo)aliphatic polyisocyanate having an average isocyanate-functionality of 2.5-3.5, where the step (b) is performed in the presence of an allophanatization catalyst and the conditions are chosen such that allophanate groups are formed between the reaction product of step (a) and the polyisocyanate, and the allophanatization catalyst comprises at least a zinc compound and the polyalkyleneetheralcohol in the step (a) exhibits a content of ions of less than 100 mmole/kg.</p> |
