Patent ID: 6218000
Filing Date: 2001-04-17
Classification: B01D,B29C,B29K,C08J,H05K,Y10T

Abstract:
Process for the production of particulate filled, microporous polytetrafluoroethylene (PTFE), comprisinga) stretching a tape of a mixture of PTFE resin and 5-50% by weight of a particulate having an average particle size of between 5 and 100 nanometers, to form a microporous film;b) sintering the tape;c) stretching the tape in a direction substantially perpendicular to the stretching in step a) to form a microporous membrane of expanded PTFE having a thickness less than 55 micrometers, a filler loading of 5-50% by weight, and wherein the membrane has a structure of PTFE nodes and fibrils with the filler being within the PTFE nodes and fibrils rather than in the pores.