Patent ID: 9438997
Filing Date: 2016-09-06
CPC Classification: H04R

Claim Text:
1. A diaphragm comprising: a paper layer including natural fibers and synthetic fibers formed of thermoplastic resin; and a skin layer formed of a same thermoplastic resin as the thermoplastic resin of the synthetic fibers and formed on one surface of the paper layer, wherein tensile strength in a circumferential direction of the diaphragm is more than one time and 1.5 times or less as high as tensile strength in a direction from a center to an outer periphery of the diaphragm, the natural fibers have a beating degree of 200 ml or more and 700 ml or less in Canadian Standard freeness, and a length of each of the natural fibers is 0.8 mm or more and less than 3 mm.