| 摘要 |
PURPOSE:To prevent the air from being caught in a reaction liquid mixture in a mold by a method wherein the reaction liquid mixture is poured in the mold from the lower part of the mold. CONSTITUTION:By a method to mold a molding from norbornene type monomer by reaction injection molding system, reaction liquid mixture is poured in a mold from the lower part of the mold. Not only the ring opening polymerization of the reaction liquid mixture is hindered by oxygen, but also its viscosity is very low and consequently the mixture easily catch the air in itself. Accordingly, when the reaction liquid mixture is poured from the lower part of the mold, the air in the mold is pushed upwards and discharged through the gap and air vent of the mold and the whole interior of the mold is gradually filled with the reaction liquid mixture without catching the air in the mixture itself. The preferable mold 1 to use has the inlet 3 of the reaction liquid mixture, which is provided at its lower part, and air vents 2 provided at parts, each of which is difficult to be filled with the reaction liquid mixture or is the last part to be filled with the reaction liquid mixture. |
