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Omega-hydrofluoroalkyl ethers, precursor carboxylic acids and derivatives thereof, and their preparation and application

  • US 6,204,299 B1
  • Filed: 06/24/1997
  • Issued: 03/20/2001
  • Est. Priority Date: 05/20/1994
  • Status: Expired due to Fees
First Claim
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1. 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; and

    3) a surfactant.

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