摘要 |
The invention provides a process for the production of flexible to semi-rigid polyurethane shaped articles with a compacted edge zone of given hardness and a significantly more flexible cell core, so-called integral foams, in which non-combustible mixtures of fluoroalkanes which comprise 1,1,1,3,3-pentafluorobutane (R 365mfc) are employed as physical blowing agents. |