| 摘要 |
<p>The invention relates to polymeric formulations comprising at least one first epoxy resin having density between 100 and 0,000 Pa·s, a blocked isocyanate, a polymer comprising hydroxy functional groups, a thermoplastic resin and a cross-linking agent, wherein the polymer comprising hydroxyl functional groups has a hydroxyl content in the range 0.65 to 0.95 meq/g, the isocyanate-equivalents-to-polymer-OH-equivalents rate being in the range 0.60 to 1.1. Preferably, the first epoxy resin is substantially semisolid at room temperature, the formulation comprising at least one second epoxy resin substantially liquid at room temperature, first and second epoxy resin being present in a weight ratio from 60:40 to 80:20. These formulations are advantageously used for manufacturing prepregs and articles of composite material according to a dry winding process. By virtue of improved stability, higher glass transition temperature, and a rheological profile which can be chemically tailored to the needs of the impregnation/dry winding process.</p> |
