METHOD OF PRODUCING CYCLIC OLEFIN-BASED RESIN MOLD ARTICLE

To provide a method of producing a cyclic olefin-based resin mold article using an injection molder in which occurrence of a black speck to the mold article is suppressed even when the injection molder is operated continuously.SOLUTION: A method of producing a resin mold article of this invention uses an injection molder including a screw having a feed section with a length of l, a compression section with a length of l, and a measurement section with a length of lin this order. A cyclic olefin-based resin material as resin material is fed to the feed section and, when the fed resin material is heated, molten, and extruded to the compression section and the measurement section, the resin material is not completely molten in a part of the compression section closer by l/4 to a boundary between the feed section and the compression section and is completely molten at a boundary between the compression section and the measurement section.SELECTED DRAWING: Figure 1 【課題】射出成形機を用いて環状オレフィン系樹脂の成形体を製造する場合において、射出成形機を連続運転した場合であっても成形体に黒点を発生しにくくする。【解決手段】長さｌ１の供給部、長さｌ２の圧縮部および長さｌ３の計量部をこの順に有するスクリューを備えた射出成形機を用いる射出成形において、供給部に、樹脂材料として環状オレフィン系樹脂材料を供給し、供給された樹脂材料を加熱して溶融しつつ圧縮部および計量部に押し出す際に、供給部と圧縮部の境界よりｌ２／４だけ供給部寄りの部分においては、樹脂材料は完全には溶融しておらず、かつ、圧縮部と計量部の境界においては、樹脂材料は完全に溶融している、樹脂成形体の製造方法。【選択図】図１