DIAPHRAGM FOR ELECTROACOUSTIC TRANSDUCER

摘要

PURPOSE:To improve both specific elastic modulus and internal loss, by mixing a filler into thermoplastic resin to increase the Young's modulus and at the same time having a lamination structure with the resin having a high internal loss. CONSTITUTION:Polypropylene is kneaded with the flaky mica powder applied with a silane coupling process to obtain the 1st film of about 180mum thickness by a extrusion molding process. While the mixture resin obtained by kneading petroleum resin with atactic polypropylene is sliced by 150mum thickness to obtain the 2nd film. Then the 1st film having counter faces applied with a corona discharge process is set on both sides of the 2nd film, and the 2nd film is fused and adhered with pressure to the 1st film. Thus a composite sheet of 440mum thickness containing an outer layer formed from the 1st film is obtained on both sides of an intermediate layer of about 80mum thickness formed from the 2nd film is obtained. This composite sheet is used to a diaphragm.