| 摘要 |
PURPOSE:To display an excellent release effect even if a using quantity of a mold release agent is little and at the same time also a quantity of the mold release agent to be infiltrated into a substrate can be reduced, by a method wherein the mold release agent is introduced into the mold by making the same into a gaseous state during an injection molding and mold release processes. CONSTITUTION:After injection molding of a substrate for various optical discs or optical cards which record or reproduce information optically within a mold by the injection molding, demolding of the substrate is performed by breaking a half of the movable side mold. A mold release agent is introduced into the mold under a gaseous state in an injection molding and mold release processes. In other words, after the demolding and prior to a start of the next injection molding, an air flow containing the mold release agent is introduced within the mold and a mold release agent coating in several molecular layers is formed on a stamper surface. With this construction, a quantity of the mold release agent remaining within the substrate is reduced and an optical disc board superior in preservation and stability can be obtained. Furthermore, simplification of a washing process of the mold release agent can be contrived. |
