×

Hydrophobic membrane materials for filter venting applications

  • US 6,884,375 B2
  • Filed: 01/08/2004
  • Issued: 04/26/2005
  • Est. Priority Date: 04/12/2002
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for preparing a membrane, the method comprising:

  • providing a casting dope comprising a solvent and a terpolymer of tetrafluoroethylene, vinylidene fluoride, and hexafluoropropylene;

    casting the dope to form a thin film;

    exposing the film to a humid atmosphere for a period of time sufficient to allow formation of surface pores;

    quenching the film in a quenching bath; and

    recovering from the quenching bath a flat sheet membrane, the membrane comprising a terpolymer of tetrafluoroethylene, vinylidene fluoride, and hexafluoropropylene, the membrane having a first porous face having a first average pore diameter, a second porous face having a second average pore diameter, and a porous supporting structure therebetween wherein the supporting structure comprises a reticulated network of flow channels, and wherein the porous faces and the porous supporting structure comprise a network of structural surfaces capable of contacting a filter stream.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×