| abstract |
PURPOSE: A molding material for sound instrument that is obtained by kneading polymethyl methacrylate together with a flake graphite powder, thus being light weight, high rigidity, high elasticity and high internal loss and giving high-temperature-resistant diaphragms and head shells. n CONSTITUTION: Polymethyl methacrylate (50W25wt%) and a flake graphite powder preferably with average particle size of less than 5μm (50W75wt%) are kneaded. Further, when desired, a rubber material such as nitrile-butadiene rubber is added thereto by 2W50wt% and they are kneaded with heat using, e.g., a kneader or roller into sheets of molding material. Then, the sheets are oriented by press or compression molding, if desired, to give the objective molding material. n COPYRIGHT: (C)1981,JPO&Japio |