Nitto-denko Corporation

Yu Kamamoto

Hisae Kitagawa

Takeo Inoue

Tamao Fukushima

The conversion element member of the present disclosure includes: a conversion element having an opening capable of functioning as a ventilation port and/or a sound-transmitting port; and a waterproof membrane. The conversion element has an outer surface provided with the opening. The waterproof membrane is joined, at a joining portion thereof, to the outer surface of the element so as to cover the opening, the joining portion having a shape surrounding the opening when viewed in a direction perpendicular to the outer surface. The waterproof membrane has a non-joining portion defined as a portion surrounded by the joining portion when viewed in the direction, the non-joining portion having a region overlapping the outer surface when viewed in the direction. A spacing distance Dbetween the membrane and the outer surface in the region is 0.01 mm to X mm, where X represents, in an indentation test on the waterproof membrane.

Conversion element member, and conversion element module and electronic device including conversion element member

Provided is a porous polytetrafluoroethylene membrane in which an absolute value of a difference in lightness between one principal surface and the other principal surface is 1.0 or more, where the lightness is lightness L* of CIE 1976 (L*, a*, b*) color space specified in JIS Z8781-4: 2013. The porous polytetrafluoroethylene membrane may be colored black or gray. The porous polytetrafluoroethylene membrane provided can have properties with a reduced coloring-induced deterioration.

Porous polytetrafluoroethylene membrane, gas-permeable membrane, and gas-permeable member

A waterproof membrane of the present disclosure has an insertion loss of 5.0 dB or less for sound with a frequency of 1 kHz, and an insertion loss of 5.0 dB or less for sound with a frequency of 10 kHz when a permeation region for sound of the waterproof membrane has an area of 1.3 mm. The waterproof membrane of the present disclosure can cope with further size reduction of the permeation region. A waterproof member of the present disclosure includes the above-mentioned waterproof membrane of the present invention and a support member joined to the waterproof membrane.

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Osaka, Japan

Yu Kamamoto