PRODUCTION OF SUBSTRATE FOR OPTICAL DISK

摘要

PURPOSE:To prevent the remaining of air in an injection nozzle and the side face of an outside circumferential ring and to prevent the generation of a drop-out by coating a UV curing resin only to the part where the injection ring and the outside circumferential ring come into contact with a stamper and packing a resin into the molding space from the injection nozzle. CONSTITUTION:The preliminary injection nozzle 14 is inserted into a mold and the acrylic and methacrylic resin 4 is previously injected to a doughnut shape to the side face 11 of the injection nozzle and the side face 12 of the outside circumferential ring. The nozzle 14 is removed and in turn the resin having the same compsn. as the compsn. of the previously injected resin is injected from the injection nozzle 7 while the spacing between a quartz flat plate 1 and the stamper 2 is maintained. An injection value 8 is closed to stop the injection where the photosetting resin 4 enters a resin pool space 5 by about half. The photosetting resin 4 is then cured by a light source 6. The cured matter of the photosetting resin is removed from the flat plate 1 and the nickel stamper 2, by which the substrate 13 having information patterns is obtd. The substrate for optical media which does not generated the drop-out and has excellent recording and reproducing characteristics is thereby obtd. at a high speed and low cost.