| 摘要 |
<p>Melt-blown fiber having an average diameter of not more than 5.0 mum, said fiber comprises at least 85 wt.-% of a propylene copolymer, wherein . said melt blown fiber and/or said propylene copolymer has/have a melt flow rate MFR2 (230° C.) measured according to ISO 1133 of at least 200 g/10 min, . said propylene copolymer has a comonomer content of 0.5 to 5.5 wt.-%, the comonomers are ethylene and/or at least one C4 to C20 alpha-olefin selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene, . the propylene copolymer has <2,1> regiodefects of not more than 0.4 mol.-% determined by 13C-spectroscopy, and . said melt blown fiber and/or said propylene copolymer fulfill(s) the equation (1). wherein Tm [° C.] is the melting temperature [given in ° C.] of melt blown fiber said and/or of said propylene copolymer measured according to ISO 11357-3, C2 [wt %] is the amount [given in weight percentage] of comonomers within said melt blown fiber and/or within said propylene copolymer determined with Fourier transform infrared spectroscopy (FTIR). Tm [ ° C . ] [ ° C . ] >= 160 - C 2 [ wt % ] × 5.25 [ wt % ] ( 1 )</p> |
