CPC B01D 61/145 (2013.01) [B01D 63/08 (2013.01); B01D 67/0002 (2013.01); B01D 69/02 (2013.01); B01D 69/10 (2013.01); B01D 71/34 (2013.01); C02F 1/444 (2013.01); B01D 2323/39 (2013.01); B01D 2325/02 (2013.01); B01D 2325/04 (2013.01); B01D 2325/34 (2013.01)] | 11 Claims |
1. A filter medium comprising:
a second support with porosity and a nanofiber web which are sequentially stacked on each of an upper portion and a lower portion of a first support with porosity; and
a channel through which a filtrate filtered in the nanofiber web flows in a direction of the first support,
wherein the nanofiber web comprises a PVDF nanofiber,
wherein the nanofiber is formed with a hydrophilic coating layer on a surface, and
wherein the hydrophilic coating layer includes 2 to 20 parts by weight of polyacrylic acid-co-maleic acid based on 100 parts by weight of PVA,
wherein the nanofiber web has a fiber average diameter ranging from 0.05 μm to 0.5 μm,
wherein the first support, the second support, and the nanofiber web satisfy condition (1), condition (2), and condition (3) below:
0.067≤(b1+c1)/a1≤0.59 and 0.028≤c1/b1≤0.43, (1)
0.0306≤(b2+c2)/a2≤0.1383 and 0.0053≤c2/b2≤0.53, and (2)
0.31≤(b3+c3)/a3≤0.72 and 0.01≤c3/b3≤0.033, (3)
wherein a1, b1, and c1 respectively refer to basis weights (g/m2) of the first support, the second support, and the nanofiber web,
a2, b2, and c2 respectively refer to thicknesses (mm) of the first support, the second support, and the nanofiber web, and
a3, b3, and c3 respectively refer to fiber average diameters (μm) of the first support, the second support, and the nanofiber web.
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