| 摘要 |
PURPOSE:To permit production of a magnetic disk substrate by using a polyphenylene sulfide PPS resin by superposing resin sheets formed of the PPS resin which does not contain the reinforcing material on both faces of a core material formed of the PPS resin contg. the reinforcing material and blanking the resulted sheet. CONSTITUTION:The PPS resin contg. the reinforcing material as the core material 1 is continuously extruded and formed to a sheet shape from a die 5 of an extrusion molding device. The long-sized resin sheets 2, 2 formed of the PPS resin without contg. the reinforcing material to the film shape are left off from coils 6, 6 and are superposed on both the top and bottom faces of the core material 1. The core material is heated in this state by a heater 8 and is then introduced into a pressurizing device 4, by which the sheets 2 are thermally compression bonded, laminated and united to the core material 1. The substrate sheet 9 obtd. in the above-mentioned manner is introduced to a blanking device and a disk shape is blanked from the sheet 9, by which the magnetic disk substrate is obtd. |
