METHOD OF MAKING MICROPOROUS MEMBRANES Russian patent published in 1996 - IPC

FIELD: chemical engineering. SUBSTANCE: method of making microporous membranes includes irradiation of polymeric film by flows of high-energy particles, for example quantum of emission, electrons or ions and consequent etching. Before irradiation the film is heated up to temperature being in the range between glass transition temperature and flow temperature, then it is deformed and cooled up to temperature less than glass transition temperature. After irradiation the film is repeatedly heated and cooled up to temperatures being in indicated ranges. Etching can be carried out before repeated heating, at the same time with it and after repeated cooling. EFFECT: facilitated manufacture. 4 cl, 2 dgw