| abstract |
The invention relates to an impact modifier, which is an isocyanate-terminated polymer, the isocyanate groups of which are partially or completely blocked by reaction with a blocking agent, wherein the isocyanate-terminated polymer is a reaction product of a) one or more polyols comprising polytetramethylene ether glycol in a fraction of at least 95 wt%, with respect to the total weight of the polyols, and b) two or more polyisocyanates, which comprise at least one diisocyanate and at least one polyisocyanate having an average isocyanate functionality of 2.5 or more, wherein the molar ratio of isocyanate groups of the one or more diisocyanates to isocyanate groups of the one or more polyisocyanates having an average isocyanate functionality of 2.5 or more lies in the range of 2 to 1 to 20 to 1. The impact modifier is suitable in particular in one-component epoxide resin formulations, in particular one-component epoxide resin glues, but also in two-component epoxide resin formulations. Very good low-temperature impact resistance can be achieved by means of the impact modifier. |