The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 2002
Filed:
Feb. 28, 2000
Marcus O. Müller, Arnhem, NL;
Erich Kessler, Hoschst im Odenw, DE;
Ralf R. Hornscheidt, Heiligenhaus, DE;
Frank Wiese, Wuppertal, DE;
Armin J. Lang, Miltenberg, DE;
Membrana GmbH, Wuppertal, DE;
Abstract
Process for producing hydrophobic polyolefinic membranes for gas exchange via thermally induced liquid-liquid phase separation is disclosed. A solution of at least one polyolefin in a solvent system, of a compound A and a compound B having a viscosity less than 60 mPa s, is extruded to form a shaped object. The compound A is a solvent and compound B preferably a non-solvent of the polymer, and the boiling point of compound A is at least 50° C. higher than that of compound B. After the shaped object leaves the die, at least one surface thereof is subjected to an atmosphere promoting evaporation of compound B, and the shaped object is subsequently cooled until the phase separation and solidification of the high-polymer-content phase take place. The integrally asymmetrical membrane producible in this manner has a porosity of greater than 50% to 75% by volume, a sponge-like, open-pored, microporous support layer without macrovoids and on average isotropic pores, and at least one separation layer with pores <100 nm, if any. The membrane is preferably used for blood oxygenation.