Patent ID: 6180008
Filing Date: 2001-01-30
Classification: B01D,C10G

Abstract:
Membrane having sufficient flux and selectivity to separate aromatic hydrocarbons from non-aromatic hydrocarbons in a feed stream under hlyperfiltration conditions comprising asymmetric polyimide membrane impregnated with at least one conditioning agent comprising a lubricating oil, wherein the polyimide is at least one copolymer derived from (a) the co-condensation of benzophenonie 3,3',4,4'-tetracarboxylic acid dianhydride and a mixture of (i) di(4-aminophenyl) methane and toluene diamine, or (ii) a mixture of 4,4'-methylenebis (phenyl isocyanate) and toluene diisocyanate; or (b) the condensation of 1H,3H-Benzo[1,2-c:4,5-c']difuran-1,3,5,7-tetrone with 5,5'-carbonybis[1,3-isobenzofuiranidione], 1,3-diisocyanato-2-methiylbenzene and 2,4-diisocyanato-1-miethylbenzene.