Patent ID: 6204299
Filing Date: 2001-03-20
Classification: A61K,A62D,B01D,B23K,C07C,C07D,C08J,C11D

Abstract:
A process for preparing a foamed plastic comprising the steps of:admixing organic polyisocyanate and high molecular weight compound with at least 2 reactive hydrogen atoms in the presence of:1) blowing agent mixture comprising at least one normally liquid omega-hydrofluoroalkyl ether compound having a saturated perfluoroaliphatic chain of carbon atoms interrupted by one or more ether oxygen atoms, the chain carbon atom at one end (the proima end) of the chain being that of a difluoromethyl group which is bonded to another chain carbon atom or to a said ether-oxygen atom, the carbon atom at the other end (the distal end) of the chain being part of a distal group selected from the group consisting of difluoromethyl, difluorochloromethyl, a straicht-chain peyfluoroalkyl, a branched-chain perfluoroalkyl, and a perfluoroalkyl substituted with a saturated perfluoroalicyclic moiety, with the proviso that where said difluoromethyl group at the proximal end is bonded to a said ether-oxygen atom, then said straight-chain perfluoroalkyl has at least 6 chain carbon atoms and said branched-chain perfluoroalkyl has at least 4 carbon atoms;2) a catalyst; and3) a surfactant.