| abstract |
The prodn. of rigid polyurethane (PU) foam with low thermal conductivity comprises reacting: (a) opt. modified polyisocyanates with (b) high-mol. wt. cpds. with reactive H atoms, and (c) opt. low-mol. wt. chain extenders and/or crosslinkers, in presence of: (d) blowing agents, (e) catalysts, and (f) opt. additives. This foam contains at least 32 wt% aromatic residues incorporated in components (a), (b) and/or opt. (c). |