Method of manufacturing acoustic diaphragm
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsKazuhiro Watanabe, Mutsuaki Murakami
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Abstract
A method of manufacturing a dome- or cone-like acoustic diaphragm by a process including the step of heating a polymeric film comprising an aromatic polyimide, a polyoxadiazole or an aromatic polyamide, to a temperature range of 2,000.degree. C. or above, and the step of pressure molding. The heating and the pressure molding may be carried out at the same time when the polymeric film is heated for its graphitization. Alternatively, the pressure molding may be carried out while the polymeric film having been graphitized by the heating is further heated. Still alternatively, a polymeric film having been pressure-molded in the course of heat polycondensation of a polyamic acid may be graphitized by heating.
Claims12
A method of manufacturing an acoustic diaphragm comprises heating a polymeric film to effect graphitization of said polymeric film and at the same time pressure-molding said film into the shape of a dome or cone while heating said film to a temperature of from 2,000.degree. C. to 3,000.degree. C.;
- said polymeric film comprising an aromatic polyimide, a polyoxadizole or an aromatic polyamide.
A method of manufacturing an acoustic diaphragm which comprises pressure-molding an aromatic polyimide film formed in the course of heat polycondensation of a polyamic acid, and then heating the molded aromatic polyimide film at a temperature of 2,000.degree. C. to 3,000.degree. C. to effect its graphitization.
Dependencies are inferred from the claim text.