| abstract |
The present invention relates to a process for manufacturing an isocyanate-terminated polyurethane prepolymer, which is intended primarily for a use in a flame retardant poly-mer. The inventive process for manufacturing an isocyanate-terminated polyurethane pre-polymer comprises the steps of (i) charging a reaction vessel with a) at least one polyol with a number average molecular weight Mn in a range of approximately 900 g/mol to approxi-mately 5000 g/mol; b) at least one multifunctional diol, wherein the at least one multifunc-tional diol comprises at least two hydroxy groups and at least one functional group selected from the group comprising carboxy, sulfonic acid groups, alkyl groups, ether groups, polyether groups and/or amine groups; (ii) adding at least one isocyanate, wherein the at least one isocyanate is used in excess with respect to the molar ratio of the isocyanate groups to the hy-droxy groups of the other components of the reaction mixture to obtain an isocyanate-terminated polyurethane prepolymer; wherein the isocyanate-terminated polyurethane prepolymer has a dynamic viscosi-ty in a range between approximately 4,000 mPa∙s and approximately 700,000 mPa∙s measured with a Brookfield DV2T EXTRA™ Vis-cometer at 30 °C according to DIN EN ISO 2884-2, dated September 2006. Further, the present invention relates to an isocyanate-terminated polyurethane prepolymer which is ob-tained by the mentioned process, a process for manufacturing the aqueous functionalized polyurethane dispersion, the aqueous functionalized polyurethane dispersion, and a use of said aqueous functionalized polyurethane dispersion. |