Abstract: Filter media for liquid purification, which can remove metal compounds or metal ions containing in polishing or washing liquids such as alkali, acid solution or ultra-pure water used for silicon wafers of semiconductors. Removal of metals from various kind of liquid such as inorganic chemicals, organic solvent, or industrial waste water are also the subject of the present invention. The Filter media made of melt-blown nonwoven substrate comprising of aethylene/norbornene copolymer represented by the following formula [1] and/or a polycyclic norbornene polymer represented by the following formulae [2](a),(b),(c) as raw material, wherein said ethylene/norbornene copolymer and said polycyclic norbornene polymer have a glass transition temperature (Tg) selected in a range from 80 to 180° C. and melt volume rate (MVR) (ISO 1133, measuring conditions: 260° C., 2.

Abstract: This invention relates to functional nonwoven filter media provided by radiation-induced graft copolymerization and its production method. Meltblown type of nonwoven (Meltblown) comprised of fine fibers, less than 8 micron in diameter, of polyolefin or polyamide is chosen as the suitable grafting trunk polymer. The production methods are composed of following steps, 1) irradiation less than 30 kGy dose to the Meltblown with electron beam or gamma ray; 2) graft copolymerization of emulsified vinyl monomer onto the Meltblown; and 3) chemical conversion of ion exchange group onto the grafted vinyl monomer. These steps are independently conducted in their suitable operation conditions.