Modification of drawn film

Abstract

The Invention relates to a drawn polymer film, comprising (A) a polymer or polymer blend and at least (B) one additional component with an average particle diameter of between 0.1 and 15 μm, which by means of (C) one or several secondary treatment steps is processed to form a membrane after being drawn. The average particle diameter of component (B) ranges between 0.1 and 15 μm, preferably 0.5-8.0 μm, with the range between 1.0 and 7.0 μm being particularly preferred. The membranes are used for alkene-alkane separation, electrodialysis, the desalinisation of seawater, in fuel cell applications and other membrane applications.

What is claimed is: 
     
         1 . A membrane formed by a process which comprises:
 providing a foil containing 20 to 98% by weight of a polymer component (A) and 80 to 2% by weight of a particle component (B), which comprises phyllosilicates or tectosilicates distributed in the matrix of the polymer component (A) and having a mean particle diameter of 0.1 to 15 μm;   stretching the foil monoaxially or biaxially to provide cavities in the foil;   filling the cavities using a process that includes replacing the cations of the phyllosilicates or the tectosilicates completely or partially by organic functionalizing hydrophobization agents and   post-treating with phosphoric acid to fill the cavities in the foil.