Text: (JP2022082168)
1. A diaphragm for alkaline water electrolysis comprising a porous membrane, wherein the porous membrane comprises an organic polymer resin and inorganic particles, the porous membrane has voids, and a void ratio of a diaphragm surface layer up to a depth of 30 μm from the diaphragm surface is 20% or greater; The diaphragm for alkaline water electrolysis has a mass loss rate due to shedding of diaphragm components after ultrasonic treatment in 30 °C water for 3 minutes at a frequency of 38 kHz and an output of 100 W of 2% or less than the diaphragm before ultrasonic treatment.
2. The diaphragm for alkaline water electrolysis according to claim 1, wherein the voids have a width of 4 μm or greater and a length of 10 μm or greater.
3. The diaphragm for alkaline water electrolysis according to claim 1 or 2, wherein the inorganic particles have a plate-like shape.
4. The diaphragm for alkaline water electrolysis according to any one of claims 1~ 3, wherein the porous membrane contains 40~ 80 parts by mass of an organic polymer resin per 100 parts by mass of the inorganic particles.
5. The diaphragm for alkaline water electrolysis according to any one of claims 1~ 4, wherein the diaphragm for alkaline water electrolysis further comprises a porous supporting body.
6. The diaphragm for alkaline water electrolysis according to claim 5, wherein the diaphragm for alkaline water electrolysis comprises a layer comprising the porous membrane and an impregnated layer in which the porous support body is impregnated with the porous membrane.
7. The diaphragm for alkaline water electrolysis according to any one of claims 1~ 6, wherein shedding matter produced by shedding of the diaphragm components has an average particle size of 2 μm or less.
8. The diaphragm for alkaline water electrolysis according to any one of claims 1~ 7, wherein the diaphragm for alkaline water electrolysis has an air permeability maintenance rate of 80% or greater after ultrasonic treatment in 30 °C water at a frequency of 38 kHz and an output of 100 W for 3 minutes. SUMMARIZE ABOVE TEXT