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Gas separation membrane

  • US 5,071,452 A
  • Filed: 08/13/1990
  • Issued: 12/10/1991
  • Est. Priority Date: 08/11/1989
  • Status: Expired due to Fees
First Claim
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1. A gas separation membrane comprising at least one film of a thickness ranging from 0.05.10-6 to 20.10-6 m, at least 90% by mole of which is at least one aromatic polyimide or copolyimide, the recurrent unit of which has formula (I):

  • ##STR12## where A represents a tetravalent aromatic radical, at least 50% by mole of which have formula (II);

    ##STR13## and B represents a bivalent aromatic radical or a mixture of bivalent aromatic radicals.

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