| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: invention relates to a novel aqueous polytetrafluoroethylene emulsion obtained using a special fluorinated emulsifying agent, and to fine polytetrafluoroethylene powder and porous material produced from said powder. Described is a porous material produced from polytetrafluoroethylene via extrusion of a paste of fine polytetrafluoroethylene powder which is obtained through coagulation of aqueous polytetrafluoroethylene emulsion obtained during emulsion polymeristion of tetrafluoroethylene in an aqueous medium using a fluorinated emulsifying agent of formula (I): CF3CF2OCF2CF2OCF2COOA, in which A is an alkali metal atom or an NH4 group taken in amount of 1500-20000 parts per million relative the final output of polytetrafluoroethylene, followed by stretching. ^ EFFECT: obtaining porous material with excellent various characteristics, made from polytetrafluoroethylene, having excellent processability during extrusion of the paste. ^ 5 cl, 3 ex, 1 tbl, 1 dwg |
