SEMI-RIGID POLYURETHANE FOAMED MATERIALS BASED ON BIURET-MODIFIED POLYISOCYANATES, COMPOSITE STRUCTURAL COMPONENTS USING SAID SEMI-RIGID POLYURETHANE FOAMED MATERIALS, AND A PROCESS FOR THE PRODUCTION THEREOF

摘要

Semi-rigid polyurethane foamed materials are described which havea density of 60.1 to 200 kg/m3. These foamed materials are obtainable bythe reaction(a) a polyisocyanate component which has an NCO content of 30-47%,and which comprises a toluene diisocyanate which has a biuretstructure and which has an NCO value within the range from 33 to47% by weight,(b) a polyether polyol component with an average molecular weight of1,000 to 12,000 and a functionality ~ 2,(c) from 0.5 to 8% by weight of water, based on the total weight ofcomponents (b), (c), (d), (e) and (f),(d) optionally, a further polyol component with an average molecularweight of 62 to less than 1,000 and a functionality ~ 2,(e) optionally, with further adjuvant substances, additives and flameretardants known in the art, and(f) optionally blowing agents,while maintaining an isocyanate index of 30 to 180 with respect to the ratio ofisocyanate groups present in component (a) to the sum ofisocyanate-reactive groups present in components (b) to (f).A process for producing said foamed materials and the use thereofin composite structural components are also described.