Method of drying thermoplastic norbornene resin, the substrate for magnetic recording media using the thermoplastic norbornene resin, the magnetic recording medium using the substrate, and the method of manufacturing the magnetic recording medium

摘要

The gas components in thermoplastic norbomene resin pellets are suppressed below certain levels by drying the resin under vacuum or under the ordinary pressure and under vacuum. A substrate for magnetic recording media is manufactured by injection-molding the resin dried by the method according to the invention. The magnetic recording medium, employing the substrate manufactured according to the invention, includes at least a magnetic layer, a protection layer on the magnetic layer and a liquid lubricant layer on the protection layer. The magnetic recording medium is manufactured by forming these layers, one after another, on the substrate according to the invention.