| 摘要 |
PURPOSE:To manufacture a loudspeaker diaphragm having a large internal loss and a high elastic modulus by executing injection molding at a specific temperature range with respect to a composite obtained by polymerizing in a multistage ultrahigh molecular weight polyolefin and low or high molecular weight polyolefin. CONSTITUTION:A forming material mainly composed of a polyolefin composite consisting of ultrahigh molecular weight polyolefin whose limiting viscosity is 10-40dl/g, measured in a 135 deg.C decalin solution and low molecular weight or high molecular weight polyolefin whose limiting viscosity is 0.1-5dl/g, measured in the 135 deg.C decalin solution, and manufactured by a multistage polymerizing method is subjected to injection molding within an injection temperature range of 150-200 deg.C, and a molecular chain of the ultrahigh molecular weight polyolefin is oriented radially from the symmetrical center of a diaphragm. The polyolefin composite used as the forming material consists of a homopolymer or a copolymer (copolymer) of alpha-olefin such as, for instance, ethylene, propyrene, 1-butene, 1-pentene, 1-hexene, etc., two components whose melting viscosity is remarkably different are mixed minutely, and what is called a polymer alloy is formed. |
