Patent ID: 8662316
Filing Date: 2014-03-04
Classification: B01D,Y10T

Abstract:
1. A filter medium for liquid filtration having a basis weight of 100 g/cm2 or less, a 30% or less strength decrease ratio as calculated from a normal state bursting strength and bursting strength when wetted in water for 30 minutes at 30° C. as described in JIS L 1096, wet bursting strength of 300 kPa or higher, and a value of the normalized standard deviation as measured with the β-ray formation tester of 0.8 or less, and a filter medium density of 0.20-0.40 g/cm3 wherein said filter medium contains 0.5-40% by weight of a non-beating NBKP of 70 μm or less in fiber diameter; and contains, as other base materials 1-60% by weight of, an ultrafine organic fiber and an ultra-fine inorganic fiber, said ultra-fine fibers being of below 5 μm in fiber diameter, and 10-60% by weight of a synthetic organic fiber and an inorganic fiber, said synthetic organic fiber and inorganic fiber being of 5 μm or higher in fiber diameter and the proportion of fibers total 100%; wherein part of the synthetic organic fiber of 5 μm or higher in fiber diameter is a fibrous organic binder; and wherein a synthetic resin type binder is applied in the amount of 5-20% by weight with respect to the above-mentioned total base materials.