| 摘要 |
1,273,717. Polytetrafluoroethylene films. DURHAM CHEMICALS Ltd., and ENERGY CONVERSION Ltd. 24 April, 1969 [25 April, 1968], No. 14610/71. Divided out of 1,256,706. Headings B5A and B5B. [Also in Division C3] The diffusivity of cellular foraminous unsintered polytetrafluoroethylene tape is reduced by subjecting the tape to pressure between the platens of a press. One surface of the tape may have a layer of electrochemical catalytic material applied thereto prior to the pressing. The tape may be of thickness 0.007 inch and may be subjected to a pressure of 1-3.75 tons/inch<SP>2</SP> with the platens being heated to 40-200‹ C. The tape may be used in electrochemical cell electrodes. |
