US Patent 10028043 Waterproof sound-permeable membrane, waterproof sound-permeable member, and electronic device

The waterproof sound-permeable membrane of the present disclosure is a waterproof sound-permeable membrane adapted to permit passage of sound and prevent ingress of water. The air permeability of the waterproof sound-permeable membrane, as expressed by Gurley number, is 20 seconds/100 mL or more. The water entry pressure of the waterproof sound-permeable membrane is 500 kPa or more. When a tensile strength at break of the waterproof sound-permeable membrane in a MD direction is denoted by T1 and a tensile strength at break of the waterproof sound-permeable membrane in a TD direction orthogonal to the MD direction is denoted by T2, a strength ratio (T1/T2) is in a range of 0.5 to 2.0.