| 摘要 |
Mo-3896 LeA 29,04/A ISOCYANATE PREPOLYMERS, A PROCESS FOR THEIR PRODUCTION AND THEIR USE IN ONE-COMPONENT COATING COMPOSTIONS The present invention relates to a process for the production of storage stable, prepolymers containing free isocyanate groups by reacting a) an organic polyisocyanate component containing one or more lacquer polyisocyanates containing (cyclo)aliphatically bound isocyanate groups, having an isocyanate content of 8 to 25% by weight and having a maximum functionality of 4.5 with b) one or more hydroxy-functional polyacrylate resins having molecular weight (Mn) of 300 to 100,000 and a content of alcoholic hydroxyl groups of 0.05 to 7% by weight in the presence of c) organic solvents and d) optionally other auxiliaries and additives, at an equivalent ratio of isocyanate groups of component a) to hydroxyl groups of component b) and optionally d) of 3:1 to 40:1, wherein the type and quantities of starting components a) and b) are selected to provide a value B of at most 4 when calculated in accordance with the formula: wherein F1 and F2 represent the NCO and OH functionalities of components a) and b), F1 representing the component with the lower functionality when the components differ in functionality and valA/valI represents the OH/NCO equivalent ratio of components a), b) and optionally d). The invention also relates to the NCO prepolymers obtained by this process and to their use for the production of one-component, moisture-curing coating compositions.
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