Inventors:
Harvey Steadly - Westport CT
Anthony J. Laccetti - Shelton CT
Assignee:
Parker Hannifin Corporation - Cleveland OH
International Classification:
B01D 1300
Abstract:
Integral gradient, skinned, submicroscopically porous, anisotropic, hydrophilic, asymmetric polyamide membranes comprising: (a) a first porous polyamide zone obtained from a polyamide solution formulated to give coagulated film with pores of a given size, (b) a fabric support imbedded in the first porous polyamide layer, and (c) a second porous polyamide zone having a skinned outer surface, obtained from a polyamide solution having the same constituents as the solution used to form the first porous polyamide zone but solution post-treated to give pores substantially smaller than those in the first porous polyamide zone, as well as a process for producing such membranes, are disclosed.