| abstract |
The present invention relates to a process for preparing at least one ethylenically unsaturated, urethane group-containing compound from (i) diisocyanate, (ii) at least one compound having at least one hydroxyl group and at least one ethylenically unsaturated, polymerizable group, (iii) and optionally at least one hydroxyl group-containing compound, in which 1 diisocyanate is subjected to a determination of the peroxide content immediately prior to the reaction, 2 (a) if the determined peroxide content is greater than or equal to 20 mmol/kg, the diisocyanate is subjected to distillative purification until the determined peroxide content is less than 20 mmol/kg, or or (b) if the determined peroxide content is less than 20 mmol/kg, no distillative purification is performed, and 3. then (i) distilled diisocyanate of (a) and/or untreated diisocyanate of (b) is reacted with (ii) at least one compound having at least one hydroxyl group and at least one ethylenically unsaturated, polymerizable group and optionally (iii) with at least one hydroxyl group-containing compound to give an ethylenically unsaturated, urethane group-containing compound. |